ELECTROCHROMIC COMPOUNDS AND OPTICAL ARTICLES CONTAINING THEM

Abstract

The invention relates to a group of novel electrochromic compounds. More specifically, it relates to benzazoles and condensed azole compounds substituted with one or several pyridinium rings and the use of these compounds as a variable transmittance medium for the manufacture of an optical article, such as an ophthalmic lens.

Claims

1: An electrochromic compound represented by formula (I): ##STR00140## wherein: A is N, .sup.+N, NR.sub.1, .sup.+NR.sub.1 or CR.sub.1; B is CR.sub.2, S, Se, O, N, NR.sub.2 or .sup.+NR.sub.2; D is CR.sub.3, N, S, O, Se, NR.sub.3 or .sup.+NR.sub.3; E is C, N or .sup.+N; R.sub.1 is H, C.sub.1-C.sub.18 alkyl, aryl or Z; R.sub.2 is H, C.sub.1-C.sub.18 alkyl, aryl, Z or aryl substituted by Z; R.sub.3 is H or C.sub.1-C.sub.18 alkyl, aryl or Z; R.sub.4 is H, C.sub.1-C.sub.18 alkyl, aryl or Z; R.sub.5 is H, C.sub.1-C.sub.18 alkyl, aryl or Z; R.sub.6 is H, C.sub.1-C.sub.18 alkyl, aryl or Z; R.sub.7 is H, C.sub.1-C.sub.18 alkyl, aryl or Z; R.sub.7 and R.sub.6 and/or R.sub.6 and R.sub.5 and/or R.sub.5 and R.sub.4 may form together an aromatic ring or heteroaromatic ring fused to the six-membered(hetero)cyclic core (Cycle C6) they are attached to, optionally substituted by Z, ##STR00141## With Z is Y is C.sub.1-C.sub.18 alkyl, (hetero)aryl or (hetero)arylalkyl; R.sub.8, R.sub.9, R.sub.10 and R.sub.11 are independently selected from H and C.sub.1-C.sub.18 alkyl; R.sub.8 and R.sub.9 or R.sub.10 and R.sub.11 may form an aromatic ring fused to the pyridium group they are attached to, When B=CZ, and when A=.sup.+N, R.sub.8 or R.sub.11 may form with A a ring, aromatic or not, fused with the five-membered heterocyclic ring (Cycle C5) A is attached to, n is selected to counterbalance the number of positive charges; X is a counterion; is a single bond or a double bond; with the 3 following provisos: 1) Cycle C5 is a five membered heterocyclic ring with 2 of A, B, D and E being independently selected from: N, NR.sub.1, .sup.+NR.sub.1, NR.sub.2, .sup.+NR.sub.2, .sup.+NR.sub.3, .sup.+NR.sub.3, S, Se and O; 2) Cycle C5 and Cycle C6 form a conjugated system; and 3) at least one of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 or R.sub.7 is Z or at least R.sub.7 and R.sub.6 form together an aromatic ring substituted by Z or at least R.sub.5 and R.sub.6 form together an aromatic ring substituted by Z or at least R.sub.5 and R.sub.4 form together an aromatic ring substituted by Z.

2: The compound of formula (I) according to claim 1, wherein said compound is represented by formulae (II), (III), (IV), (V), (VI), (VII), (VIII), (IX) or (X): ##STR00142## ##STR00143## wherein A, B, D, E, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11, when present, are as defined in claim 1; and wherein Z, Y, n and X are also as defined in claim 1.

3: The compound of formula (I) according to claim 1 wherein A is N, .sup.+N, NR.sub.1 or .sup.+NR.sub.1; and/or B is N, NR.sub.2 or .sup.+NR.sub.2; and/or D is N, NR.sub.3 or .sup.+NR.sub.3.

4: The compound of formula (I) according to claim 1 wherein E is N or .sup.+N and/or D is S.

5: The compound of formula (II) according to claim 2 wherein A is N, .sup.+N, NR.sub.1 or .sup.+NR.sub.1; D is NR.sub.3, .sup.+NR.sub.3, S, Se, or O; E is C.

6: The compound of formula (II) according to claim 5 wherein A is N.sup.+ or .sup.+NR.sub.1; D is S; and E is C.

7. The compound of formula (II) according to claim 6 wherein A is .sup.+N; D is S; E is C and; R.sub.8 forms with A, a five or six-membered ring, unsaturated or saturated, fused with Cycle C5 A is attached to and is represented by formula (XI), (XII) or (XIII). ##STR00144##

8: The compound of formula (II) according to claim 6 wherein A is .sup.+NR.sub.1; D is S; and E is C.

9: The compound of formula (II) according to claim 8 wherein R.sub.7 and R.sub.6 and/or R.sub.6 and R.sub.5 and/or R.sub.5 and R.sub.4 form together an aromatic ring or heteroaromatic ring fused to the (hetero)cyclic core (Cycle C6) they are attached to, optionally substituted by Z.

10: The compound of formula (II) according to claim 8 wherein R.sub.8 and R.sub.9 or R.sub.10 and R.sub.11 form an aromatic ring fused to the pyridium group they are attached to.

11: The compound of formula (I) according to claim 1, wherein said compound is selected from the group consisting of: ##STR00145## ##STR00146## ##STR00147## ##STR00148##

12: An electrochromic composition comprising at least one compound as defined in claim 1.

13: The electrochromic composition according to claim 12, wherein said composition further comprises a host medium, a mesomorphous media or a gel.

14: An electrochromic device comprising a compound as defined in claim 1.

15: The electrochromic device according to claim 14, wherein said electrochromic device is selected from an optical article, a window, a visor, a mirror, a head mounted device and a display.

16: An electrochromic device comprising an electrochromic composition as defined in claim 12.

17: The electrochromic device according to claim 16, wherein said electrochromic device is selected from an optical article, a window, a visor, a mirror, a head mounted device and a display.

Description

EXAMPLES

[0132] This invention will be further illustrated by the following non-limiting examples which are given for illustrative purposes only and should not restrict the scope of the appended claims.

Synthesis of Compounds of the Invention

1. Iso)thiazole Benzologues

Example 1

2-(Pyridin-4-yl)benzothiazole

[0133] ##STR00052##

[0134] A solution of 2-aminobenzenethiol (7.01 g, 56.1 mmol) and pyridine-4-carboxaldehyde (6.00 g, 56.1 mmol) in EtOH (28 mL) was stirred under air for 120 h. The resulting mixture was filtered, and the residue washed with cooled MeOH (20 mL) and air dried to give the title compound (7.63 g, 64%) as a cream powder. The liquors were reduced in volume and filtered to give a second crop (0.73 g, 6%), .sub.H (CDCl.sub.3, 400 MHz) 7.46 (1H, dt, J=1.2 and 8.2 Hz), 7.56 (1H, dt, J=1.2 and 8.2 Hz), 7.93-7.99 (3H, m), 8.14 (1H, ddd, J=8.2 Hz) and 8.78 (2H, dd, 1.6 and J=4.5 Hz); .sub.C (CDCl.sub.3, 100 MHz) 121.21, 121.89, 123.93, 126.22, 126.84, 135.21, 140.47, 150.79, 153.97 and 165.11.

4-(Benzothiazol-2-yl)-1-hexylpyridin-1-ium iodide

[0135] ##STR00053##

[0136] A solution of 2-(pyridin-4-yl)benzothiazole (0.54 g, 2.5 mmol) and 1-iodohexane (1.62 g, 7.6 mmol) in MeCN (40 mL) in the dark under N.sub.2 was heated at reflux for 24 h, then cooled and diluted with Et.sub.2O (50 mL). The precipitate was filtered off, washed with Et.sub.2O (320 mL) and air dried to give the title compound (0.77 g, 71%) as a yellow powder, .sub.H (DMSO-d.sub.6, 400 MHz) 0.85 (3H, t, J=7.0 Hz), 1.21-1.37 (6H, m), 1.88-2.01 (2H, m), 4.65 (2H, t, J=7.3 Hz), 7.62-7.72 (2H, m), 8.25 (1H, dd, J=0.9 and 7.6 Hz), 8.35 (1H, dd, J=1.1 and 7.6 Hz), 8.76 (2H, d, 6.8 Hz) and 9.23 (2H, d, J=6.8 Hz); .sub.C (DMSO-d.sub.6, 100 MHz) 14.32, 22.34, 25.54, 31.06, 31.19, 61.11, 123.72, 124.82, 125.47, 128.23, 128.33, 136.64, 146.29, 146.73, 153.83 and 161.90.

4-(Benzothiazol-2-yl)-1-hexylpyridin-1-ium tetrafluoroborate

[0137] ##STR00054##

[0138] A solution of 4-(benzothiazol-2-yl)-1-hexylpyridin-1-ium iodide (0.77 g, 1.8 mol) in MeOH/H.sub.2O (40 mL, 1:1) was added dropwise to a solution of NaBF.sub.4 (3.96 g, 36 mmol) in water (80 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered, washed with water (25 mL) and air dried to give the title compound (0.69 g, 98%) as a pale yellow powder, .sub.H (DMSO-d.sub.6, 400 MHz) 0.88 (3H, t, J=6.9 Hz), 1.25-1.39 (6H, m), 1.89-2.02 (2H, m), 4.67 (2H, t, J=7.4 Hz), 7.64-7.75 (2H, m), 8.28 (1H, dd, J=1 and 8.3 Hz), 8.37 (1H, dd, J=1 and 7.6 Hz), 8.79 (2H, d, 6.8 Hz) and 9.23 (2H, d, J=6.8 Hz); .sub.C (DMSO-d.sub.6, 100 MHz) 13.75, 21.78, 24.98, 30.50, 30.63, 60.57, 123.14, 124.26, 124.90, 127.67, 127.77, 136.09, 145.72, 146.19, 153.27 and 161.33.

Compound 1: 2-(1-Hexylpyridin-1-ium-4-yl)-3-methylbenzothiazol-3-ium bis(tetrafluoroborate)

[0139] ##STR00055##

[0140] A mixture of 4-(benzothiazol-2-yl)-1-hexylpyridin-1-ium tetrafluoroborate (0.59 g, 1.5 mmol) in MeOTs (1.71 g) was heated at 180 C. for 2 h, cooled, triturated with Et.sub.2O (340 mL) and dried under N.sub.2 to give 0.81 g of a light tan powder. The solid was redissolved in MeOTs (1.71 g), heated at 180 C. for 1 h, cooled, triturated again with Et.sub.2O (430 mL) and air dried. The gummy solid was dissolved in MeOH/water (25 mL, 1:4) and added dropwise to a solution of NaBF.sub.4 (3.38 g, 30.7 mmol) in water (50 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered, washed with water (25 mL), air dried and triturated with hot MeOH (8 mL). The residue was cooled, filtered and washed with cold MeOH (2 mL) to give the title compound (0.38 g, 51%) as a cream powder, .sub.H [(CD.sub.3).sub.2CO, 400 MHz] 0.91 (3H, t, J=7.0 Hz), 1.29-1.47 (4H, m), 1.49-1.61 (2H, m), 2.20-2.32 (2H, m), 4.58 (3H, s), 5.04 (2H, t, J=7.7 Hz), 8.07 (1H, t, J=7.9 Hz), 8.17 (1H, t, J=7.8 Hz), 8.58 (1H, d, J=8.4 Hz), 8.68 (1H, d, J=8.4 Hz), 8.89 (2H, bd, J=5.7 Hz) and 9.59 (2H, d, J=6.5 Hz); .sub.F [(CD.sub.3).sub.2CO, 376 MHz]-151.40, 151.35; .sub.C [(CD.sub.3).sub.2CO, 100 MHz] 13.30, 22.14, 25.54, 30.98, 31.37, 38.42, 62.91, 117.97, 124.70, 129.92, 130.08, 131.05, 131.42, 141.05, 142.81, 146.47 and 168.29.

Example 2

4-(Benzothiazol-2-yl)-1-phenylpyridin-1-ium triflate

[0141] ##STR00056##

[0142] A mixture of 2-(pyridin-4-yl)benzothiazole (1.34 g, 6.3 mmol), diphenyliodonium triflate (3.47 g, 8.1 mmol), Cu(OAc).sub.2.Math.H.sub.2O (0.11 g, 0.55 mmol, 10 mol %) in dry DMF (25 mL) was heated at 100 C. for 16 h, cooled and the solvent removed under reduced pressure. The residue was triturated with Et.sub.2O (340 mL) and air dried to give the title compound (2.66 g, 96%) as a yellow powder, .sub.H [(CD.sub.3).sub.2CO, 400 MHz] 7.67-7.86 (5H, m), 8.01-8.09 (2H, m), 8.27-8.37 (2H, m), 9.02 (2H, d, 6.8 Hz) and 9.56 (2H, d, J=6.8 Hz); .sub.F[(CD.sub.3).sub.2CO, 376 MHz]77.76; .sub.C (DMSO-d.sub.6, 100 MHz) 122.93, 124.60, 124.85, 125.25, 128.01, 128.18, 130.60, 131.78, 136.92, 142.95, 142.95, 145.92, 148.33, 154.18 and 160.76.

Compound 2: 3-Methyl-2-(1-phenylpyridin-1-ium-4-yl)benzothiazol-3-ium bis(tetrafluoroborate)

[0143] ##STR00057##

[0144] A mixture of 4-(benzothiazol-2-yl)-1-phenylpyridin-1-ium triflate (1.07 g, 2.4 mmol) MeOTs (3.62 g, 19 mmol) was heated at 180 C. for 3 h, cooled and triturated with Et.sub.2O (340 mL) and the residue dried under vacuum. The residue was dissolved in MeOH (5 mL) and added dropwise to a solution of NaBF.sub.4 (5.37 g, 48.8 mmol) in water (40 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate was filtered, washed with water (25 mL) and air dried. The residue was triturated with hot MeOH (220 mL), filtered and air dried to give the title compound (0.72 g, 62%) as a grey powder, .sub.H (DMSO-d.sub.6, 400 MHz) 4.32 (3H, s), 7.80-7.90 (3H, m), 7.92-7.99 (2H, m), 8.04 (1H, t, J=7.8 Hz), 8.14 (1H, t, J=7.5 Hz), 8.55 (1H, d, J=8.6 Hz), 8.69 (1H, d, J=8.2), 8.79 (2H, d, J=6.7 Hz) and 9.77 (2H, d, J=6.7 Hz); .sub.F (DMSO-d.sub.6, 376 MHz) 148.23, 148.18; .sub.C (DMSO-d.sub.6, 100 MHz) 118.42, 125.21, 125.57, 129.92, 130.10, 130.99, 131.21, 131.61, 132.40, 141.77, 142.47, 142.92, 146.55 and 168.49.

Example 3

(E)-3,4-Dihydronaphthalen-1(2H)-one O-acetyl oxime

[0145] ##STR00058##

[0146] Solid hydroxylamine hydrochloride (7.14 g, 103 mmol) was added in one portion to a solution of 3,4-dihydronaphthalen-1(2H)-one (10.00 g, 68.5 mmol) in EtOH (30 mL). The resulting solution was heated at 60 C. for 1 h, poured into HCl (200 mL, 2 M) and extracted with EtOAc (350 mL). The combined organic extracts were washed with brine (50 mL), then water (50 mL) and dried (Na.sub.2SO.sub.4) and the solvent removed under reduced pressure. The residue was dissolved in pyridine (32 mL) to which Ac.sub.2O (13.97 g, 137 mmol) and DMAP (16 mg) were then added. The resulting solution was stirred at rt for 1 h, poured into HCl (300 mL, 2 M) and extracted with EtOAc (3200 mL). After drying (Na.sub.2SO.sub.4) the solvent was removed under reduced pressure. The residue was twice crystallized from EtOAc/hexanes to give the title compound (10.51 g, 76%) as colourless needles, .sub.H (CDCl.sub.3, 400 MHz) 1.87-1.93 (2H, m), 2.27 (3H, s), 2.77-2.82 (2H, br. t, J=6.1 Hz), 2.86-2.90 (2H, m), 7.16-7.20 (1H, m), 7.22-7.26 (1H, m), 7.34 (1H, dt, J=1.4 and 7.4 Hz) and 8.13-8.16 (1H, m); .sub.C (CDCl.sub.3, 100 MHz) 19.92, 21.33, 25.60, 29.55, 125.61, 126.59, 128.72, 128.95, 130.74, 140.93, 161.31 and 169.22.

2-(Pyridin-4-yl)naphtho[1,2-d]thiazole

[0147] ##STR00059##

[0148] A mixture of (E)-3,4-dihydronaphdialen-1(2H-one O-acetyl oxime (4.00 g, 19.7 mmol), pyridine-4-carboxaldehyde (1.40 g, 13.1 mmol) and sulfur (10.09 g, 39.4 mmol) in DMSO (60 mL) under N.sub.2 was heated at 120 C. for 4 h, poured into water (200 mL) and extracted with EtOAc (3100 mL). The combined extracts were washed with water (100 mL), dried (Na.sub.2SO.sub.4) and the solvent removed under reduced pressure. The residue was chromatographed on silica using EtOAc (25-30% in hexanes gradient) as eluent. The fluorescent band was collected and the solvent removed under reduced pressure. The residue was crystallised from hot EtOAc/hexanes at 0 C. to give the title compound (1.14 g, 33%) as brown needles, .sub.H (CDCl.sub.3, 600 MHz) 7.64 (1H, ddd, J=1.3, 6.9 and 8.1 Hz), 7.74 (1H, ddd, J=1.2, 6.9 and 8.2 Hz), 7.87-7.90 (1H, br. dm, J=8.7 Hz), 7.95 (1H, d, J=8.7 Hz), 7.98-8.01 (1H, br. m, J=8.1 Hz), 8.06 (2H, d, J=6.0 Hz), 7.80 (2H, d, J=6.0 Hz) and 8.93 (1H, br. d, J=8.2 Hz); .sub.C (CDCl.sub.3, 125 MHz) 118.90, 120.98, 123.96, 126.61, 127.17, 127.40, 128.22, 128.92, 132.16, 132.33, 140.77, 150.56, 150.78 and 163.88.

4-(Naphtho[1,2-d]thiazol-2-yl)-1-phenylpyridin-1-ium trifluoromethanesulfonate

[0149] ##STR00060##

[0150] A mixture of 2-(pyridin-4-yl)naphtho[1,2-d]thiazole (1.12 g, 4.3 mmol), diphenyliodonium trifluoromethanesulfonate (2.20 g, 5.1 mmol) and Cu(OAc).sub.2.Math.H.sub.2O (86 mg, 10 mol %) in DMF (30 mL) under N.sub.2 was heated at 100 C. for 16 h. The resulting solution was cooled and the solvent removed under reduced pressure. The residue was triturated with Et.sub.2O (330 mL) and air dried to give the title compound (2.09 g, 100%) as a brown powder which was used without further purification in the next step, .sub.H (DMSO-d.sub.6, 400 MHz) 7.71-7.91 (5H, m), 7.93-8.01 (2H, m), 8.16-8.23 (2H, m), 8.40 (1H, d, J=8.9 Hz), 8.92 (1H, d, J=8.1 Hz), 8.96 (2H, d, J=7.0 Hz) and 9.49 (2H, d, J=7.0 Hz); .sub.F (DMSO-d.sub.6, 376 MHz) 77.75.

Compound 3: 1-Methyl-2-(1-phenylpyridin-1-ium-4-yl)naphtho[1,2-d]thiazol-1-ium bis(tetrafluoroborate)

[0151] ##STR00061##

[0152] A solution of 4-(naphtho[1,2-d]thiazol-2-yl)-1-phenylpyridin-1-ium trifluoromethanesulfonate (2.09 g, 4.3 mmol) in methyl trifluoromethanesulfonate (9.03 g, 55.1 mmol) was heated at reflux. After 2 days the solution was diluted with Et.sub.2O (40 mL) and the residue collected by filtration. The filtrand was washed with Et.sub.2O (210 mL) and air dried. The solid was extracted with water (2100 mL) and the solvent removed under reduced pressure. The residue was then dissolved in MeOH (5 mL) and added dropwise to a solution of NaBF.sub.4 (5.05 g, 45.9 mmol) in water (40 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered, washed with water (35 mL) and triturated with hot MeOH (20 mL). After cooling, the residue was filtered off and air dried to give the title compound (0.23 g, 8%) as a pale yellow solid. .sub.H (DMSO-d.sub.6, 400 MHz) 4.74 (3H, s), 7.76-8.12 (7H, m), 8.40-8.70 (3H, br. m), 8.82 (2H, br. d, J=3.3 Hz), 9.11 (1H, d. dm, J=9.0 Hz) and 9.79 (2H, br. d, J=3.3 Hz); .sub.F (DMSO-d.sub.6, 376 MHz) 148.25 and 148.20.

Example 4

Quinoline-4-carbaldehyde

[0153] ##STR00062##

[0154] A mixture of 4-methylquinoline (6.00 g, 41.9 mmol), p-toluenesulfonic acid (7.22 g, 42 mmol) and iodine (4.26 g, 16.8 mmol, 40 mol %) in DMSO (300 mL) was heated at 130 C. for 16 h, cooled, poured into water (400 mL) and basified (K.sub.2CO.sub.3). The mixture was extracted with EtOAc (5100 mL). The combined organic extracts were washed with aq. Na.sub.2S.sub.2O.sub.3 (300 mL), then brine (200 mL) and dried (Na.sub.2SO.sub.4). The solvent was removed under reduced pressure to give the title compound (6.11 g, 93%) as a beige solid, .sub.H (CDCl.sub.3, 400 MHz) 7.75 (1H, ddd, J=1.4, 6.9 and 8.4 Hz), 7.80 (1H, d, J=4.3 Hz), 7.83 (1H, d, J=1.4, 6.9 and 8.4), 8.23 (1H, ddd, J=0.7, 1.4 and 8.4 Hz), 9.11 (1H, ddd, J=0.7, 1.4 and 8.4 Hz), 9.21 (1H, d, J=4.3 Hz) and 10.53 (1H, s); .sub.C (CDCl.sub.3, 100 MHz) 123.89, 124.44, 125.87, 129.42, 130.06, 130.22, 136.76, 149.28, 150.48 and 192.92.

2-(Quinolin-4-yl)-2,3-dihydrobenzothiazole

[0155] ##STR00063##

[0156] A solution of quinoline-4-carbaldehyde (3.00 g, 19.1 mmol) and 2-aminobenzenethiol (2.39 g, 19.1 mmol) in EtOH (40 mL) was stirred under air for 2 days. The solvent was decanted and the residue crystallised from hot EtOH (40 mL) and cooled to 0 C., The product was collected by filtration, washed with EtOH (10 mL) and air dried to give the title compound (2.38 g, 47%) as orange prisms. The filtrate liquors were reduced to give a second crop (1.19 g, 23%) as a yellow powder, .sub.H (DMSO-d.sub.6, 400 MHz) 6.62 (1H, dt, J=1.2 and 7.5 Hz), 6.78 (1H, br. dd, J=1.1 and 7.8 Hz), 6.94 (1H, dt, J=1.3 and 7.7 Hz), 6.99 (1H, dd, J=1.2 and 7.4 Hz), 7.15 (2H, s), 7.62 (1H, d, J=4.5 Hz), 7.67 (1H, ddd, J=1.4, 6.9 and 8.4 Hz) 7.79 (1H, ddd, J=1.4, 6.9, 8.4 Hz) 8.07 (2H, br. t, J=8.8 Hz) and 8.88 (1H, d, J=4.4 Hz); .sub.C (DMSO-d.sub.6, 100 MHz) 4.46, 109.88, 117.60, 119.59, 121.94, 123.84, 124.74, 125.14, 126.21, 127.39, 129.94, 130.26, 148.02, 148.16, 148.40 and 151.08.

2-(Quinolin-4-yl)benzothiazole

[0157] ##STR00064##

[0158] Solid DDQ (1.29 g, 5.7 mmol) was added to a solution of 2-(quinolin-4-yl)-2,3-dihydrobenzothiazole (1.50 g, 5.7 mmol) in DCM (1.2 L). The mixture was stirred at rt for 1 h, then filtered through silica using EtOAc (60% in hexanes) as eluent. The solvent was removed under reduced pressure and the residue dissolved in EtOAc (200 mL) and washed sequentially with KOH (200 mL, 2 M), water (2100 mL) and brine (100 mL). The extracts were dried (Na.sub.2SO.sub.4) and the solvent removed under reduced pressure. The residue was crystallised from hot EtOAc/hexanes. After cooling to 4 C., the product was collected by vacuum filtration and washed with cold hexanes to give the title compound (1.19 g, 80%) as pale lime needles, .sub.H (CDCl.sub.3, 400 MHz) 7.52 (1H, ddd, J=1.3, 7.3 and 7.9 Hz), 7.60 (1H, ddd, J=1.3, 7.2 and 8.2 Hz), 7.70 (1H, ddd, J=1.3, 6.8 and 8.7 Hz), 7.80 (1H, d, J=4.4 Hz), 7.82 (1H, ddd, J=1.4, 6.9 and 8.4 Hz), 8.02 (1H, ddd, J=0.7, 1.3 and 8.0 Hz), 8.22 (1H, ddd, J=0.7, 1.4 and 8.4 Hz) 8.24 (1H, ddd, J=0.6, 1.2 and 8.2 Hz), 9.00 (1H, ddd, J=0.7, 1.4 and 8.5 Hz) and 9.05 (1H, d, J=4.4 Hz); .sub.C (CDCl.sub.3, 100 MHz) 121.63, 122.19, 124.12, 124.98, 126.04, 126.17, 126.76, 128.19, 130.00 (2C), 135.34, 138.32, 149.20, 149.80, 154.18, 164.80.

4-(Benzothiazol-2-yl)-1-phenylquinolin-1-ium tetrafluoroborate

[0159] ##STR00065##

[0160] A mixture of 2-(quinolin-4-yl)benzothiazole (1.00 g, 3.8 mmol), diphenyliodonium trifluoromethanesulfonate (2.46 g, 5.7 mmol) and Cu(OAc).sub.2.Math.H.sub.2O (76 mg, 10 mol %) in DMF (30 mL) under N.sub.2 was heated at 100 C. for 16 h. The resulting solution was cooled and the solvent removed under reduced pressure, the residue was triturated with Et.sub.2O (340 mL) to give a mixture (62:38) of product and starting material. The residue and diphenyliodonium trifluoromethanesulfonate (1.64 g, 3.8 mmol) and Cu(OAc).sub.2.Math.H.sub.2O (76 mg, 10 mol %) in DMF (30 ml) under N.sub.2 was heated at 100 C. for 16 h. The resulting solution was cooled and the solvent removed under reduced pressure. The residue was triturated with Et.sub.2O (340 mL) to give a mixture of product and reactant (70:30). This solid was dissolved in warm MeOH (20 mL) and added dropwise to a solution of NaBF.sub.4 (8.40 g, 76 mmol) in water (50 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate collected by filtration and washed with water (5 mL). The solid was dissolved in hot MeOH (20 mL) and added dropwise to NaBF.sub.4 (8.40 g, 76 mmol) in water (50 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered off, washed with water (5 mL) and air dried to give a yellow powder. The powder was triturated with hot EtOH (25 mL) to give the title compound (1.01 g, 54%) as a yellow powder, .sub.H (CDCl.sub.3, 400 MHz) 7.67-7.79 (2H, m), 7.79-8.92 (6H, m), 8.12-8.24 (2H, m), 8.27 (1H, br. d, J=7.6 Hz), 8.38 (1H, br. d, J=7.9 Hz), 8.68 (1H, d, J=6.2 Hz), 9.52 (1H, d, J=6.2 Hz) and 9.69 (1H, br. dd, J=1.5 and 8.3 Hz); .sub.F (CDCl.sub.3, 376 MHz) 154.67 and 154.62; Sc (CDCl.sub.3, 100 MHz) 120.31, 122.03, 122.56, 124.59, 126.34, 126.89, 127.61, 127.76, 128.91, 130.47, 131.13, 131.79, 135.76, 136.23, 140.35, 140.92, 148.20, 149.02, 154.37 and 161.44.

Compound 4: 3-Methyl-2-(1-phenylquinolin-1-ium-4-yl)benzothiazol-3-ium tetrafluoroborate

[0161] ##STR00066##

[0162] A mixture of 4-(benzothiazol-2-yl)-1-phenylquinolin-1-ium tetrafluoroborate (1.01 g, 2.4 mmol) in MeOTs (4.61 g, 24.8 mmol) was heated at 180 C. for 3 h, then cooled and triturated with Et.sub.2O (330 mL). The washings were discarded and the residue then dried under N.sub.2. The residue was dissolved in hot MeOH (40 mL) and added dropwise to a solution of NaBF.sub.4 (4.55 g, 41.4 mmol) in water (40 mL) with stirring. Stirring was continued for 0.5 h and the precipitate collected by filtration and washed with water (25 mL), and then with hot MeOH (5 mL) and air dried. The residue was triturated with AcMe (3 mL) to give the title compound (0.70 g, 56%) as an off white powder, .sub.H [(CD.sub.3).sub.2CO, 600 MHz] 4.52 (3H, s), 7.88-8.02 (5H, m), 8.07 (1H, app. br. d, J=9.0 Hz), 8.12 (1H, ddd, J=0.7, 7.3 and 8.7 Hz), 8.19-8.24 (2H, m), 8.39 (1H, ddd, J=1.3, 7.0 and 9.0 Hz), 8.57 (1H, ddd, J=0.6, 1.3 and 8.5 Hz), 8.64 (1H, ddd, J=0.7, 1.6, 7.9 Hz), 8.75 (1H, ddd, J=0.6, 1.2 and 7.3 Hz), 9.00 (1H, d, J=5.9 Hz) and 9.97 (1H, d, J=5.9 Hz); .sub.F [(CD.sub.3).sub.2CO, 470 MHz] 151.44 and 151.39; .sub.C [(CD.sub.3).sub.2CO, 125 MHz] 38.76, 118.09, 121.40, 124.76, 125.84, 126.59, 127.07, 128.87, 130.00, 130.73, 131.06, 132.25, 132.32, 132.52, 137.16, 140.39, 140.69, 141.56, 142.98, 150.58 and 166.95.

Example 5

3-(Pyridin-4-yl)-1,2-benzisothiazole

[0163] ##STR00067##

[0164] BuLi (2.5 M in hexane) (32.2. mL, 80.5 mmol) was added dropwise to a stirred solution of thioanisole (2.00 g, 16.1 mmol) and N,N,N,N-tetramethylethylenediamine (5.60 g, 7.24 mL, 48.3 mmol) in tert-butyl methyl ether (80 mL) under N.sub.2. The reaction mixture was then stirred under N.sub.2 at room temperature for 3 h. 4-Pyridinecarbonitrile (16.76 g, 161 mmol) was then added portion wise and the reaction mixture was then stirred under N.sub.2 at room temperature for 24 h. The reaction mixture was then carefully quenched with sat. NH.sub.4Cl (100 mL) and extracted with DCM (3200 mL). The organic layers were combined, dried (Na.sub.2SO.sub.4), filtered and the solvent was removed under reduced pressure. The resulting residue was chromatographed on silica gel [eluent=1:9 graduated to 4:6 EtOAc:DCM]. The solvent of the resulting column fractions was removed under reduced pressure and the resulting residue was again chromatographed on silica gel [eluent=1:9 graduated to 4:6 EtOAc:DCM]. The solvent of the resulting column fractions was removed under reduced pressure and the resulting residue was recrystallised from hot petroleum ether and filtered to give the title compound (0.33 g, 15%) as colourless crystals. The filtrate from the recrystallisation was left to stand at 20 C. for 16 h whereupon a second crop was obtained (0.15 g, 7%) as colourless crystals. Yield 0.48 g, 22%. .sub.H (CDCl.sub.3, 400 MHz) 8.81 (2H, d, J=5.3 Hz), 8.18 (1H, d, J=8.2 Hz), 8.02 (1H, d, J=8.2 Hz), 7.79 (2H, d, J=5.9 Hz), 7.59 (1H, t, J=7.3 Hz) and 7.50 (1H, t, J=7.3 Hz); .sub.C (CDCl.sub.3, 100 MHz) 161.4, 153.9, 150.5, 142.2, 133.36, 127.9, 125.6, 124.1, 123.0 and 120.2.

Compound 5: 4-(1,2-Benzisothiazol-3-yl)-1-phenylpyridin-1-ium tetrafluoroborate

[0165] ##STR00068##

[0166] 3-(Pyridin-4-yl)-1,2-benzisothiazole (0.36 g, 1.7 mmol), diphenyliodonium trifluoromethanesulfonate (1.12 g, 2.6 mmol) and Cu(OAc).sub.2. H.sub.2O (34 mg, 0.17 mmol) were dissolved in DMF (20 mL) under N.sub.2 and the reaction mixture was stirred at 100 C. for 16 h. The reaction mixture was cooled to room temperature and the solvent was removed under reduced pressure. The resulting pale yellow solid was triturated with diethyl ether (350 mL), filtered and dried under reduced pressure. The resulting pale yellow solid was dissolved in hot MeOH (150 mL) and added dropwise through a cotton wool plug to a stirred solution of NaBF.sub.4 (15.0 g) in H.sub.2O (300 mL) whereupon a pale yellow precipitate formed. The suspension was stirred for 30 minutes and then filtered under reduced pressure. The resulting solid was washed with water (30 mL) and then dried under reduced pressure to give a pale yellow powder. The solid was then dissolved in hot acetone and added dropwise through a cotton wool plug back into the filtrate (which had been reduced by ca. 30% under vacuum) to give a pale yellow precipitate. The resulting suspension was filtered under reduced pressure and the solid so obtained, washed with water (30 mL) and then dried under reduced pressure to give the title compound as a pale yellow powder. Yield 0.38 g, 59%. .sub.H (DMSO-d.sub.6, 400 MHz) 9.55 (2H, d, J=6.9 Hz), 8.84 (2H, d, J=6.9 Hz), 8.52 (2H, d, J=8.9 Hz), 8.07-7.95 (2H, m) and 7.92-7.71 (5H, m); .sub.C (DMSO-d.sub.6, 100 MHz) 157.4, 154.0, 148.8, 145.6, 142.5, 132.8, 131.4, 130.3, 128.6, 126.8, 126.6, 124.8, 123.9 and 121.5; .sub.F (DMSO-d.sub.6, 376 MHz) 148.22 (4F, br. m).

Example 6

Compound 6: 2-Methyl-3-(1-phenylpyridin-1-ium-4-yl)-1,2-benzisothiazol-2-ium bis(hexafluorophosphate)

[0167] ##STR00069##

[0168] 4-(1,2-Benzisothiazol-3-yl)-1-phenylpyridin-1-ium tetrafluoroborate (0.30 g, 0.8 mmol) was suspended in methyl trifluoromethanesulfonate (0.8 g, 5.4 mmol) and the reaction mixture was stirred under N.sub.2 at 100 C. for 80 minutes. The reaction mixture was then stirred under N.sub.2 at 40 C. for 4 h. After cooling to room temperature, diethyl ether (50 mL) was added and the resulting suspension was filtered to give a tan powder that was then triturated with ether (350 mL) and dried under reduced pressure. This tan powder was then dissolved in hot MeOH (50 mL) and added dropwise through a cotton wool plug to a stirred solution of NH.sub.4PF.sub.6 (10.0 g) in H.sub.2O (200 mL) whereupon a tan coloured precipitate formed. The precipitate was then washed with water (30 mL) and then dried under reduced pressure to give a pale tan powder. The pale tan powder was then recrystallised from hot MeOH to give the title compound as a pale tan powder Yield 0.18 g, 38%. .sub.H (DMSO-d.sub.6, 400 MHz) 9.81 (2H, d, J=6.9 Hz), 8.75 (2H, d, J=6.9 Hz), 8.71 (1H, d, J=6.6 Hz), 8.18 (1H, ddd, J=8.5, 7.3, 0.9 Hz), 8.10 (1H, d, J=6.6 Hz), 8.05-7.82 (6H, m) and 4.33 (3H, s); .sub.C (DMSO-d.sub.6, 100 MHz) 159.3, 147.8, 146.2, 142.5, 142.4, 134.5, 131.9, 130.9, 130.5, 129.3, 128.8, 127.0, 124.7, 122.9 and 39.5; .sub.F (DMSO-d.sub.6, 376 MHz) 70.14 (12F, d, J=711.5 Hz).

2. (Benz)Imidazoles and Fused-Ring Derivatives

Example 7

2-(Pyridin-4-yl)-1H-benzimidazole

[0169] ##STR00070##

[0170] A solution of o-phenylenediamine (10.10 g, 93.5 mmol) and pyridine-4-carboxaldehyde (10.00 g, 93.5 mmol) in EtOH (500 mL) was stirred under air for 72 h and the solvent removed under reduced pressure. The residue was crystallised from EtOAc/hexanes then triturated with hot EtOAc three times to give the title compound (11.44 g, 63%) as a tan powder, .sub.H (DMSO-d.sub.6, 400 MHz) 7.26 (2H, bs), 7.59 (1H, vbs), 7.71 (1H, vbs), 8.80 (2H, d, J=6.1 Hz), 8.75 (2H, d, J=6.1 Hz) and 13.26 (1H, bs).

1-Methyl-2-(pyridin-4-yl)-1H-benzimidazole

[0171] ##STR00071##

[0172] A mixture of 2-(pyridin-4-yl)-1H-benzimidazole (5.33 g, 27.3 mmol), Mel (5.33 mL, 12.15 g, 85.6 mmol) and KOH (7.83 g, 140 mmol) in acetone (660 mL) was stirred at rt for 2 h and poured into PhMe (700 mL). The resulting solution was washed with water (1 L), brine (100 mL), dried (Na.sub.2SO.sub.4) and the solvent removed under reduced pressure. The residue was filtered through neutral alumina using EtOAc as eluent. The solvent was removed under reduced pressure and the residue crystallised from EtOAc/hexanes to give the title compound (2.80 g, 49%) as yellow plates, .sub.H (CDCl.sub.3, 400 MHz) 3.83 (3H, s), 7.72-7.46 (3H, m), 7.72 (2H, d, J=6.0 Hz), 7.83-7.87 (1H, m) and 8.06 (2H, d, J=6.0 Hz); .sub.C (CDCl.sub.3, 100 MHz) 31.84, 109.88, 120.37, 123.03, 123.45, 123.74, 136.74, 137.86, 142.91, 150.38 and 150.76.

1-Hexyl-4-(1-methyl-1H-benzimidazol-2-yl)pyridin-1-ium tetrafluoroborate

[0173] ##STR00072##

[0174] A solution of 1-methyl-2-(pyridin-4-yl)-1H-benzimidazole (1.47 g, 7 mmol) and 1-iodohexane (4.47 g, 21.1 mmol) in MeCN (40 mL) was heated at reflux in the dark under N.sub.2 with stirring. After 24 h, the resulting mixture was cooled, diluted with Et.sub.2O (60 mL), filtered, washed with Et.sub.2O (30 mL) and dried under vacuum. The hygroscopic orange powder was dissolved in MeOH (30 mL) and added dropwise to a solution of NaBF.sub.4 (4.55 g, 41.4 mmol) in water (200 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate was filtered, washed with water (310 mL) and air dried to give the title compound (1.91 g, 73%) as a pale yellow powder, .sub.H [(CD.sub.3).sub.2CO, 400 MHz] 0.88 (3H, t, J=7.3 Hz), 1.27-1.56 (6H, m), 2.15-2.27 (2H, m), 4.23 (3H, s), 4.93 (2H, t, J=7.7 Hz), 7.39 (1H, ddd, J=1.1, 7.1 and 8.2 Hz), 7.48 (1H, ddd, J=1.2, 7.1 and 8.2 Hz), 7.70-7.74 (1H, m), 7.80-7.84 (1H, m), 8.80 (2H, d, J=6.9 Hz) and 9.34 (2H, d, J=6.9 Hz Hz); .sub.F [(CD.sub.3).sub.2CO, 376 MHz]-151.70 and 151.54; .sub.C [(CD.sub.3).sub.2CO, 100 MHz] 13.31, 22.17, 25.54, 31.00, 31.24, 32.08, 61.60, 111.15, 120.61, 123.44, 125.00, 127.04, 137.95, 143.21, 145.02, 145.87 and 147.05.

Compound 7: 2-(1-Hexylpyridin-1-ium-4-yl)-1,3-dimethyl-1H-benzimidazol-3-ium bis(tetrafluoroborate)

[0175] ##STR00073##

[0176] A mixture of 1-hexyl-4-(1-methyl-1H-benzimidazol-2-yl)pyridin-1-ium tetrafluoroborate (0.50 g, 1.3 mmol) in MeOTs (4.00 g, 21.5 mmol) was heated at 180 C. for 90 min, cooled and then triturated with Et.sub.2O (330 mL). The residue was dissolved in MeOH (20 mL) and added drop wise to a solution of NaBF.sub.4 (20.97 g, 190 mmol) in water (100 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered, washed with water (23 mL) and air dried to give 2-(1-hexylpyridin-1-ium-4-yl)-1,3-dimethyl-1H-benzimidazol-3-ium bis(tetrafluoroborate) (0.45 g, 71%) as a grey powder, .sub.H (CD.sub.3OD, 400 MHz) 0.91-0.99 (3H, m), 1.35-1.59 (6H, m), 2.10-2.22 (2H, m), 4.07 (6H, s), 4.81 (2H, t, J=7.6 Hz), 7.81-7.88 (2H, m), 8.05-8.12 (2H, m), 8.61 (2H, d, J=5.4 Hz) and 9.43 (2H, d, J=5.4 Hz); .sub.F (DMSO-d.sub.6, 376 MHz) 148.25; Sc (DMSO-d.sub.6, 100 MHz) 14.34, 22.34, 25.60, 31.14, 31.37, 33.44, 62.15, 114.19, 128.06, 130.84, 132.49, 136.91, 145.57 and 146.60.

Example 8

Compound 8: 2-(1-hexylpyridin-1-ium-4-yl)-1,3-dimethyl-1H-benzimidazol-3-ium bis(hexafluorophosphate)

[0177] ##STR00074##

[0178] Solid ammonium hexafluorophosphate (1.16 g, 7.1 mmol) was added to the aqueous filtrate and washings obtained during the preparation of compound 3 above and the resulting precipitate filtered, washed with water (22 mL), triturated with hot MeOH (2 mL) and air dried to give 2-(1-hexylpyridin-1-ium-4-yl)-1,3-dimethyl-1H-benzimidazol-3-ium bis(hexafluorophosphate) (0.21 g, 27%) as a cream powder; .sub.H (DMSO-d.sub.6, 400 MHz) 0.89 (3H, t, J=6.8 Hz), 1.25-1.47 (6H, m), 1.94-2.08 (2H, m), 3.97 (6H, s), 4.74 (2H, m), 7.81-7.88 (2H, m), 8.15-8.23 (2H, m), 8.63 (2H, d, J=6.4 Hz) and 9.48 (2H, d, J=6.4 Hz); .sub.F (DMSO-d.sub.6, 376 MHz) 70.13 (d, J=710 Hz); .sub.C (DMSO-d.sub.6, 100 MHz) 14.34, 22.35, 25.60, 31.14, 31.40, 33.47, 62.14, 114.20, 128.09, 130.87, 132.48, 136.90, 145.57 and 146.61.

Example 9

1-Hexyl-2-(pyridin-4-yl)-1H-benzimidazole

[0179] ##STR00075##

[0180] A mixture of 2-(pyridin-4-yl)-1H-benzimidazole (2.00 g, 10.3 mmol), powdered KOH (0.92 g, 16.4 mmol) and 1-iodohexane (2.39 g, 11.3 mmol) in anhydrous DMSO (30 mL) under N.sub.2 was stirred at rt for 24 h then poured into water (100 ml) and extracted with DCM (3100 mL). The combined extracts were washed with water (100 mL), dried (Na.sub.2SO.sub.4) and the solvent removed under reduced pressure. The residue was filtered through silica using EtOAc as eluent. The solvent was removed under reduced pressure and the residue triturated with hexanes (350 mL), filtered, washed with hexanes and air dried to give the title compound (2.53 g, 91%) as a tan powder, .sub.H (CDCl.sub.3, 400 MHz) 0.77-0.87 (3H, m), 1.17-1.35 (6H, m), 1.83-1.96 (2H, m), 4.450 (2H, t, J=7.6), 7.47-7.66 (3H, m), 7.90 (2H, d, J=6 Hz), 7.94 (1H, d, J=8 Hz) and 8.93 (2H, d, J=6 Hz); .sub.C (CDCl.sub.3, 100 MHz) 13.85, 22.36, 26.26, 29.70, 30.99, 46.00, 111.72, 118.10, 124.02, 126.43, 126.58, 133.56, 134.98, 135.17, 147.07 and 149.00.

Compound 9: 3-Hexyl-1-methyl-2-(1-methylpyridin-1-ium-4-yl)-1H-benzimidazol-3-ium bis(hexafluorophosphate)

[0181] ##STR00076##

[0182] A mixture of 1-hexyl-2-(pyridin-4-yl)-1H-benzimidazole (0.51 g, 1.84 mmol) in MeOTs (1.71 g, 9.2 mmol) was heated at 180 C. for 3 h, cooled, triturated with Et.sub.2O (340 mL) and the residue air dried. The residue was dissolved in MeOH (8 mL) and added dropwise to a solution of NaBF.sub.4 (8.10 g, 73.6 mmol) in water (100 mL) with stirring. Stirring was continued for 0.5 h. Ammonium hexafluorophosphate (10 g, 61 mmol) was added and stirring continued for 0.5 h. The resulting precipitate was filtered, washed with water (210 mL), triturated with hot MeOH (40 mL), cooled, filtered, washed with MeOH (5 mL) and air dried to give the title compound (0.96 g, 87%) as a colourless powder, .sub.H [(CD.sub.3).sub.2CO, 400 MHz] 0.83 (3H, t, J=6.7), 1.17-1.45 (6H, m), 1.93-2.02 (2H, m), 4.17 (3H, s), 4.63 (2H, t, J=7.7 Hz), 4.84 (3H, s), 7.87-7.95 (2H, m), 8.17-8.33 (2H, m), 8.98 (2H, d, J=6 Hz) and 9.61 (2H, d, J=6 Hz); .sub.F [(CD.sub.3).sub.2CO, 376 MHz]-72.687 (d, J=710 Hz); .sub.C [(CD.sub.3).sub.2CO, 100 MHz] 13.20, 22.19, 25.80, 29.44, 31.07, 32.82, 47.06, 49.33, 99.81, 113.72, 113.86, 128.01, 130.43, 131.81, 132.86, 137.48, 145.90 and 147.99.

Example 10

4-(1-Methyl-1H-benzimidazol-2-yl)-1-phenylpyridin-1-ium triflate

[0183] ##STR00077##

[0184] A mixture of 1-methyl-2-(pyridin-4-yl)-1H-benzimidazole (1.00 g, 4.8 mmol), diphenyliodonium triflate (3.08 g, 7.2 mmol), Cu(OAc).sub.2.Math.H.sub.2O (9.6 mg, 0.48 mmol, 10 mol %) in dry DMF (50 mL) was heated at 100 C. for 16 h, cooled and the solvent removed under reduced pressure. The residue was triturated with Et.sub.2O (100 mL), air dried and then crystallised from hot MeOH (10 mL). The product was isolated by filtration, washed with MeOH and air dried to give the title compound (1.33 g, 64%) as a yellow powder, .sub.H [(CD.sub.3).sub.2CO, 400 MHz] 4.294 (3H, s), 7.38-7.45 (1H, m), 7.47-7.53 (1H, m), 7.71-7.90 (5H, m), 8.01-8.11 (2H, m), 8.95 (2H, d, 7 Hz) and 9.51 (2H, d, J=7 Hz); .sub.F [(CD.sub.3).sub.2CO, 376 MHz]-78.86; .sub.C [(CD.sub.3).sub.2CO, 100 MHz] 32.21, 111.26, 120.77, 123.65, 124.62, 125.32, 127.03, 130.60, 131.68, 138.12, 142.98, 143.39, 144.99, 146.72 and 146.88.

Compound 10: 1,3-Dimethyl-2-(1-phenylpyridin-1-ium-4-yl)-1H-benzimidazol-3-ium bis(tetrafluoroborate)

[0185] ##STR00078##

[0186] A mixture of 4-(1-methyl-1H-benzimidazol-2-yl)-1-phenylpyridin-1-ium triflate (0.54 g, 1.2 mmol) in MeOTs (4.62 g, 24.8 mmol) was heated at 180 C. for 3 h, cooled, triturated with Et.sub.2O (50 mL), the residue was filtered off, washed with Et.sub.2O (210 mL) and air dried. The residue was dissolved in MeOH (10 mL) and added dropwise to a solution of NaBF.sub.4 (2.73 g, 24.8 mmol) in water (50 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered, washed with water (25 mL) and air dried. The residue was triturated with hot MeOH (5 mL), filtered and air dried to give the title compound (0.49 g, 83%) as a pale tan powder, .sub.H (DMSO-d.sub.6, 400 MHz) 4.04 (6H, s), 7.80-8.01 (7H, m), 8.19-8.29 (2H, m), 8.81 (2H, d, J=6.5 Hz) and 9.82 (2H, d, J=6.5 Hz); .sub.F (DMSO-d.sub.6, 376 MHz) 148.26, 148.20; .sub.C (DMSO-d.sub.6, 100 MHz) 33.49, 114.25, 125.24, 128.15, 130.84, 130.99, 132.41, 132.53, 137.83, 142.96, 145.50 and 146.81.

Example 11

Compound 11: 1-Hexyl-3-methyl-2-(1-phenylpyridin-1-ium-4-yl)-1H-benzimidazol-3-ium bis(hexafluorophosphate)

[0187] ##STR00079##

[0188] A mixture of 1-hexyl-2-(pyridin-4-yl)-1H-benzimidazole (0.8.0 g, 2.9 mmol), diphenyliodonium triflate (1.85 g, 4.3 mmol), Cu(OAc).sub.2.Math.H.sub.2O (58 mg, 0.29 mmol, 10 mol %) in dry DMF (30 mL) was heated at 100 C. for 16 h, cooled and the solvent removed under reduced pressure. The residue was triturated with Et.sub.2O (330 mL) and dried under vacuum. The residue was heated in MeOTs (4.26 g, 22.4 mmol) at 180 C. for 2 h, cooled and then diluted with Et.sub.2O (80 mL). The solvent was decanted and the residue triturated with Et.sub.2O (330 mL) and dried under vacuum. The residue was dissolved in MeOH (20 mL) and added drop wise to a solution of ammonium hexafluorophosphate (4.16 g, 28.7 mmol) in water (100 mL). The precipitate was filtered and washed with water (210 mL) and air dried to give the title compound (0.68 g, 38%) as a cream powder, .sub.H [(CD.sub.3).sub.2CO, 400 MHz] 0.82 (3H, t, J=6.9 Hz), 1.17-1.45 (6H, m), 1.96-2.04 (2H, m), 4.19 (3H, s), 4.66 (2H, t, J=7.7 Hz), 7.81-7.95 (5H, m), 7.99-8.10 (2H, m), 8.17-8.32 (2H, m), 9.13 (2H, bd, J=5.2 Hz) and 9.89 (2H, bd, J=5.2 Hz); .sub.F [(CD.sub.3).sub.2CO, 376 MHz]-72.47 (d, J=710 Hz); .sub.C [(CD.sub.3).sub.2CO, 100 MHz] 13.31, 22.18, 25.82, 29.49, 31.06, 32.92, 47.14, 113.76, 113.94, 124.76, 128.08, 130.75, 130.95, 131.89, 132.35, 132.96, 138.59, 143.02, 144.71 and 147.04.

3. Imidazo[1,2-a]pyridines

Example 12

7-Bromo-2-phenylimidazo[1,2-a]pyridine A

[0189] ##STR00080##

[0190] A mixture of phenacyl bromide (4.00 g, 20.1 mmol), 4-bromopyridin-2-amine (2.90 g, 16.8 mmol) and NaHCO.sub.3 (1.69 g, 20.1 mmol) in MeOH (80 mL) was heated at reflux for 5 h, cooled and the solvent reduced. Water (200 mL) was added and the resulting mixture extracted with DCM (3100 mL), dried (Na.sub.2SO.sub.4) and the solvent removed under reduced pressure. The residue was chromatographed on silica using MeOH (5% in DCM) as eluent. The solvent was removed under reduced pressure and the residue crystallised from DCM/hexanes to give the title compound (2.07 g, 39%) as a cream powder, .sub.H (CDCl.sub.3, 400 MHz) 6.91 (1H, dd, J=1.9 and 7.1 Hz), 7.34-7.40 (1H, m), 7.43-7.49 (2H, m), 7.83-7.87 (2H, m), 7.92-7.98 (2H, m) and 8.00 (2H, dd, J=0.5 and 7.1 Hz); .sub.C (CDCl.sub.3, 100 MHz) 108.27, 116.34, 118.21, 119.80, 125.72, 126.12, 128.30, 128.80, 133.27, 145.83 and 146.71.

2-Phenyl-7-(pyridin-4-yl)imidazo[1,2-a]pyridine C

[0191] ##STR00081##

[0192] A mixture of 7-bromo-2-phenylimidazo[1,2-a]pyridine A (1.18 g, 4.3 mmol), and 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (1.32 g, 6.4 mmol), K.sub.2CO.sub.3 (0.90 g, 6.5 mmol) and Pd(PPh.sub.3).sub.4 (0.20 g, 4 mol %) in degassed PhMe (40 mL) and EtOH (40 mL) under N.sub.2 was heated at reflux for 16 h, cooled, poured into water (50 ml) and extracted with DCM (340 mL). The combined extracts were dried (Na.sub.2SO.sub.4) and the solvent removed under reduced pressure. The residue was chromatographed on silica using MeOH (5% in DCM) as eluent. The band with Rf=0.5 was collected, the solvent removed and the residue triturated with hot PhMe (15 mL). After cooling the product was collected and air dried to give the title compound (1.02 g, 87%) as a cream powder, .sub.H (CDCl.sub.3, 400 MHz) 7.12 (1H, dd, J=1.6 and 7 Hz), 7.35-7.42 (1H, m), 7.45-7.52 (2H, m), 7.59 (2H, dd, J=1.5 and 4.6 Hz), 7.94-8.03 (4H, m), 8.25 (1H, dd, J=0.9 and 7 Hz) and 8.74 (2H, dd, J=1.4 and 4.7 Hz); .sub.C (CDCl.sub.3, 100 MHz) 108.43, 111.29, 115.22, 120.96, 125.90, 126.12, 128.34, 128.83, 133.42, 134.26, 145.67, 145.87, 147.38 and 150.66.

1-Hexyl-4-(2-phenylimidazo[1,2-a]pyridin-7-yl)pyridin-1-ium iodide F

[0193] ##STR00082##

[0194] A mixture of 2-phenyl-7-(pyridin-4-yl)imidazo[1,2-a]pyridine C (1.02 g, 3.8 mmol) and 1-iodohexane (2.39 g, 11.3 mmol) in MeCN (40 mL) was heated at reflux for 16 h, cooled, the solvent reduced, and the mixture diluted with Et.sub.2O (50 mL). The precipitate was filtered, washed with Et.sub.2O (230 mL) and air dried to give the title compound (1.81 g, 99%) as an orange powder, .sub.H (CD.sub.3OD, 400 MHz) 0.94 (3H, t, J=6.9 Hz), 1.32-1.51 (6H, m), 2.00-2.14 (2H, m), 4.63 (2H, t, J=7.4 Hz), 7.37-7.57 (4H, m), 7.99 (2H, d, J=7.9 Hz), 8.29 (1H, s), 8.43 (1H, s), 8.53 (2H, d, J=6.3 Hz), 8.68 (1H, d, J=7.1 Hz) and 9.01 (2H, d, J=6.3 Hz); .sub.C (CD.sub.3OD, 100 MHz) 12.85, 22.08, 25.50, 30.91, 30.98, 60.92, 110.62, 110.81, 116.23, 124.51, 125.89, 127.48, 128.49, 128.61, 130.34, 132.67, 144.53 and 153.97

1-Hexyl-4-(2-phenylimidazo[1,2-a]pyridin-7-yl)pyridin-1-ium tetrafluoroborate

[0195] ##STR00083##

[0196] A solution of 1-hexyl-4-(2-phenylimidazo[1,2-a]pyridin-7-yl)pyridin-1-ium iodide F (1.81 g, 3.7 mmol) in MeOH (20 mL) was added dropwise to a solution of NaBF.sub.4 (2.47 g, 22.4 mmol) in water (100 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered, washed with water (5 mL) and air dried to give the title compound (1.66 g, 100%) as a golden yellow powder which was used without further purification in the next step.

Compound 12: 7-(1-Hexylpyridin-1-ium-4-yl)-1-methyl-2-phenylimidazo[1,2-a]pyridin-1-ium bis(tetrafluoroborate)

[0197] ##STR00084##

[0198] A mixture of 1-hexyl-4-(2-phenylimidazo[1,2-a]pyridin-7-yl)pyridin-1-ium tetrafluoroborate (1.66 g, 3.7 mmol) and MeOTs (2.79 g, 15 mmol) was heated at 180 C. for 2 h, cooled, triturated with Et.sub.2O (350 mL) and air dried. The residue was dissolved in MeOH (25 mL) and added dropwise to a solution of NaBF.sub.4 (16.48 g, 150 mmol) with stirring. The resulting precipitate was filtered, washed with water (5 mL), then dissolved in warm MeOH (50 mL) and added dropwise to a solution of NaBF.sub.4 (16.48 g, 150 mmol) in water (250 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered. The residue was triturated with EtOH (3 ml), filtered and air dried to give the title compound (0.38 g, 19%) as a pale green powder. The ethanolic liquors were added dropwise to a solution of NaBF.sub.4 (16.48 g, 150 mmol) in water (50 mL) with stirring. The resulting precipitate was filtered, washed with water (10 mL) and air dried to give a second crop (0.45 g, 22%) as a khaki powder; .sub.H [(CD.sub.3).sub.2CO, 400 MHz] 0.88 (3H, t, J=6.8 Hz), 1.26-1.55 (6H, m), 2.12-2.27 (2H, m), 4.26 (3H, s), 4.91 (2H, t, J=7.2 Hz), 7.70 (3H, bs), 7.82 (2H, bs), 8.26 (1H, bs, J=6.6 Hz), 8.69 (1H, bs), 8.86 (2H, bd, J=5.8 Hz), 9.05 (1H, bs), 9.21 (1H, bd, J=6.6 Hz) and 9.34 (2H, bd, J=5.8 Hz); .sub.F (CDCl.sub.3, 376 MHz) 151.02, 150.97; .sub.C (CDCl.sub.3, 100 MHz) 13.31, 22.16, 25.54, 30.98, 31.26, 32.42, 61.73, 111.65, 113.97, 116.12, 125.24, 126.39, 129.44, 130.01, 130.29, 131.13, 138.32, 140.23, 140.38, 145.62 and 151.68.

Example 13

7-Bromo-2-(pyridin-4-yl)imidazo[1,2-a]pyridine B

[0199] ##STR00085##

[0200] A mixture of 4-(bromoacetyl)pyridine hydrobromide (8.00 g, 28.5 mmol), 4-bromopyridin-2-amine (4.1 g, 23.7 mmol) and NaHCO.sub.3 (4.78 g, 56.9 mmol) in MeOH (80 mL) was heated at reflux for 5 h, cooled and the solvent reduced in volume. Water (200 mL) was added and the resulting mixture extracted with DCM (3150 mL), dried (Na.sub.2SO.sub.4) and the solvent removed under reduced pressure. The residue was chromatographed on silica using MeOH (5% in DCM) as eluent. The fluorescent band with Rf=0.6 (5% MeOH in DCM) was collected. The solvent was removed under reduced pressure and the residue crystallised from MeOH (5 mL) at 3 C., filtered and air dried to give the title compound (0.68 g, 10%) as a light tan powder, .sub.H (CDCl.sub.3, 400 MHz) 6.96 (1H, dd, J=1.7 and 7.2 Hz), 7.82 (2H, d, J=6 Hz), 7.86 (1H, bs), 8.00 (1H, bs), 8.04 (1H, d, J=7.2 Hz) and 8.69 (2H, d, J=6 Hz); .sub.C (CDCl.sub.3, 100 MHz) 110.02, 117.09, 119.21, 120.19, 120.33, 125.95, 140.69, 143.88, 146.07 and 150.40.

7-Phenyl-2-(pyridin-4-yl)imidazo[1,2-a]pyridine D

[0201] ##STR00086##

[0202] A mixture of 7-bromo-2-(pyridin-4-yl)imidazo[1,2-a]pyridine B (1.17 g, 4.3 mmol) and phenylboronic acid (0.78 g, 6.4 mmol), K.sub.2CO.sub.3 (0.88 g, 6.4 mmol) and Pd(PPh.sub.3).sub.4 (0.25 g, 5 mol %) in degassed PhMe (30 mL) and EtOH (30 mL) under N.sub.2 was heated at reflux for 24 h, cooled, poured into water (100 mL) and extracted with DCM (380 mL). The extracts were dried (Na.sub.2SO.sub.4) and the solvent removed under reduced pressure. The residue was chromatographed on silica using MeOH (5% in DCM) as eluent. The solvent was removed under reduced pressure and the residue triturated with hexanes containing a few drops of DCM. The residue was filtered off, washed with hexanes and air dried to give the title compound (1.02 g, 88%) as a light tan powder, .sub.H (CDCl.sub.3, 400 MHz) 7.16 (1H, dd, J=1.6 and 7 Hz), 7.41-7.57 (2H, m), 7.66-7.72 (2H, m), 7.83-7.92 (3H, m), 8.03 (1H, s), 8.21 (1H, d, J=7 Hz) and 8.70 (2H, d, J=6 Hz); .sub.C (CDCl.sub.3, 100 MHz) 109.55, 113.14, 114.54, 120.29, 125.66, 126.74, 128.53, 129.19, 138.40, 138.57, 141.16, 143.81, 146.49 and 150.37.

1-Hexyl-4-(7-phenylimidazo[1,2-a]pyridin-2-yl)pyridin-1-ium iodide G

[0203] ##STR00087##

[0204] A mixture of 7-phenyl-2-(pyridin-4-yl)imidazo[1,2-a]pyridine D (1.00 g, 3.7 mmol) and 1-iodohexane (2.62 g, 12.4 mmol) in MeCN (40 mL) was heated at reflux for 16 h, cooled, diluted with Et.sub.2O (100 ml) and stirred for 0.5 h. The resulting precipitate was filtered, washed with Et.sub.2O (340 mL) and air dried to give the title compound (1.73 g, 97%) as a dull yellow powder, .sub.H (CD.sub.3OD, 400 MHz) 0.95 (3H, t, J=6.8 Hz), 1.32-1.54 (6H, m), 2.00-2.13 (2H, m), 4.61 (2H, t, J=7.3 Hz), 7.40-7.59 (4H, m), 7.81 (2H, d, J=7.6 Hz), 7.87 (1H, s), 8.56 (2H, d, J=6 Hz), 8.61 (1H, d, J=7.2 Hz), 8.87 (1H, s) and 8.96 (2H, d, J=6 Hz); .sub.C (CD.sub.3OD, 100 MHz) 12.85, 22.07, 25.49, 30.90, 60.82, 112.96, 114.05, 115.63, 123.02, 126.49, 127.25, 128.74, 128.94, 137.62, 138.98, 140.88, 144.41, 147.30 and 149.56.

Compound 13: 2-(1-Hexylpyridin-1-ium-4-yl)-1-methyl-7-phenylimidazo[1,2-a]pyridin-1-ium bis(tetrafluoroborate)

[0205] ##STR00088##

[0206] A solution of 1-hexyl-4-(7-phenylimidazo[1,2-a]pyridin-2-yl)pyridin-1-ium iodide G (1.73 g, 3.8 mmol) in MeOH (50 mL) was added dropwise by filtration through a cotton wool plug to NaBF.sub.4 (10.00 g, 90 mmol) water (100 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate was collected by filtration, washed with water (25 mL) and air dried. The resulting solid and MeOTs (2.87 g, 15.4 mmol) was heated at 180 C. with stirring for 2 h. The resulting oil was cooled, triturated with Et.sub.2O (550 mL) and air dried. The resulting gummy solid was dissolved in MeOH (30 mL) and added dropwise to a solution of NaBF.sub.4 (7.54 g, 68.5 mmol) in water (100 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate collected, dissolved in hot MeOH (60 mL) and added dropwise to NaBF.sub.4 (7.54 g, 68.5 mmol) in water (100 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered, washed with water (210 mL) and air dried. The solid was crystallised from hot MeOH (30 mL), filtered and air dried to give the title compound (1.37 g, 74%) as a tan powder, .sub.H [(CD.sub.3).sub.2CO, 400 MHz] 0.90 (3H, t, J=7 Hz), 1.29-1.59 (6H, m), 2.16-2.28 (2H, m), 4.41 (3H, s), 4.96 (2H, t, J=7.5 Hz), 7.59-7.69 (3H, m), 8.02-8.16 (3H, m), 8.65 (1H, bs), 8.70 (2H, d, J=6.2 Hz), 9.02 (1H, bs), 9.12 (1H, d, J=7 Hz) and 9.41 (2H, d, J=6.2 Hz); .sub.F [(CD.sub.3).sub.2CO, 376 MHz] 151.24, 151.18; .sub.C [(CD3).sub.2CO, 100 MHz] 13.29, 22.14, 25.54, 30.98, 31.25, 32.80, 62.15, 107.70, 116.81, 117.43, 127.72, 128.36, 129.55, 130.05, 130.73, 133.24, 135.84, 142.18, 142.50, 145.77 and 147.56.

Example 14

2,7-Di(pyridin-4-yl)imidazo[1,2-a]pyridine E

[0207] ##STR00089##

[0208] A mixture of 7-bromo-2-(pyridin-4-yl)imidazo[1,2-a]pyridine B (1.25 g, 4.6 mmol) and 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (1.22 g, 5.9 mmol), K.sub.2CO.sub.3 (0.82 g, 5.9 mmol) and Pd(PPh.sub.3).sub.4 (0.26 g, 5 mol %) in degassed PhMe (30 mL) and EtOH (30 mL) under N.sub.2 was heated at reflux for 16 h, cooled and the solvent removed under reduced pressure. The residue was washed with water (350 mL) and air dried. The residue was chromatographed on silica (pretreated with Et.sub.3N 10% in DCM) using Et.sub.3N (10% in DCM) to Et.sub.3N/MeOH/DCM (12/3/85) gradient as eluent. The fractions were evaporated under reduced pressure and the residue triturated with hexanes. The resulting solid was dissolved in MeOH (10 mL) and water (100 mL) added. The resulting precipitate was filtered, washed with water and air dried to give a yellow powder which was used without further purification in the next step, .sub.H (CD.sub.3OD, 400 MHz) 7.38 (1H, dd, J=1.7 and 7.2 Hz), 7.84 (2H, d, J=6.3 Hz), 7.96 (2H, d, J=6.2 Hz), 7.98 (1H, bs), 8.51 (1H, bs), 8.54-8.62 (2H, m) and 8.65 (2H, d, J=6.2 Hz); .sub.C (CD.sub.3OD, 100 MHz) 111.88, 111.99, 114.05, 120.46, 121.38, 127.36, 135.64, 141.74, 142.94, 145.89, 146.28, 149.28 and 149.58.

4,4-(Imidazo[1,2-a]pyridine-2,7-diyl)bis(1-hexylpyridin-1-ium) bis(tetrafluoroborate)

[0209] ##STR00090##

[0210] A solution of 2,7-di(pyridin-4-yl)imidazo[1,2-a]pyridine E (0.80 g, 2.9 mmol) and 1-iodohexane (3.74 g, 17.6 mmol) in MeCN (50 mL) was heated at reflux for 16 h, cooled, the solvent reduced in volume (20 mL) and Et.sub.2O (60 mL) added. The resulting precipitate was filtered, washed with Et.sub.2O (230 mL) and air dried to give 1.69 g. The yellow powder dissolved in MeOH (60 mL) was added dropwise with via filtration through a cotton wool plug to NaBF.sub.4 (6.47 g, 58.8 mmol) in water (300 mL) with stirring. The resulting precipitate was filtered, washed with ice cold water (220 mL) and air dried to give the title compound (1.32 g, 72%) as a green fluorescent powder, .sub.H (DMSO-d.sub.6, 400 MHz) 0.83-0.94 (6H, m), 1.24-1.39 (12H, m), 1.90-2.03 (4H, m), 4.54-4.65 (4H, m), 7.75 (1H, dd, J=1.4 and 7.3 Hz), 8.62-8.76 (5H, m), 8.93 (2H, d, J=7.2 Hz), 9.10 (2H, d, J=6.7 Hz), 9.16 (1H, bs) and 9.20 (2H, d, J=6.7 Hz); .sub.F (DMSO-d.sub.6, 376 MHz) 148.21, 148.16; .sub.C (DMSO-d.sub.6, 100 MHz) 14.31, 14.32, 22.34, 22.35, 25.57, 25.59, 31.02, 31.07, 31.10, 60.57, 60.61, 112.43, 117.54, 118.58, 123.59, 125.09, 129.20, 132.08, 141.17, 145.40, 145.51, 145.89, 148.60 and 152.42.

Compound 14: 4,4-(1-Methylimidazo[1,2-a]pyridine-1-ium-2,7-diyl)bis(1-hexylpyridin-1-ium) tris(tetrafluoroborate)

[0211] ##STR00091##

[0212] A mixture of 4,4-(imidazo[1,2-a]pyridine-2,7-diyl)bis(1-hexylpyridin-1-ium) bis(tetrafluoroborate) (1.17 g, 1.9 mmol) and MeOTs (2.83 g, 15.2 mmol) was heated at 180 C. for 2 h, cooled and triturated with Et.sub.2O (50 mL). The residue was filtered and dried under vacuum to give 1.85 g. The solid was dissolved in MeOH (30 mL), added dropwise to a solution of NaBF.sub.4 (30 g, 270 mmol) in water (250 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered, washed with water (25 mL) and air dried. The residue was dissolved in MeOH/H.sub.2O (30 mL, 1:1) and added dropwise to NaBF.sub.4 (20 g, 182 mmol) in water (150 ml) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered, washed with water (25 mL) and air dried to give the title compound (0.99 g, 73%) as a grey powder, .sub.H [(CD.sub.3).sub.2CO, 400 MHz] 0.84-0.96 (6H, m), 1.27-1.59 (12H, m), 2.16-2.28 (4H, m), 4.42 (3H, s), 4.91-5.04 (4H, m), 8.33 (1H, bd, J=6.7 Hz), 8.73 (2H, bd, J=6 Hz), 8.90 (2H, bd, J=6 Hz), 8.12 (2H, app. bs), 9.29 (1H, bd, J=7 Hz), 8.40 (2H, bd, J=6.4 Hz) and 9.45 (2H, bd, J=6 Hz); .sub.F [(CD.sub.3).sub.2CO, 376 MHz]151.17, 151.12; .sub.C [(CD3).sub.2CO, 100 MHz] 13.29, 22.14, 25.54, 30.98, 31.25, 31.28, 33.13, 61.85, 62.27, 111.97, 116.76, 117.63, 126.64, 128.75, 130.89, 134.01, 140.01, 141.69, 141.84, 145.70, 145.85 and 151.48.

4. Phenanthroimidazoles

Example 15

6,9-Dibromo-1,2-bis[4-(tert-butyl)phenyl]-1H-phenanthro[9,10-d]imidazole

[0213] ##STR00092##

[0214] To a stirred mixture of 4-tert-butylaniline (2.20 g, 14.6 mmol, 2.35 mL, 1.5 equiv.) and 4-tert-butylbenzaldehyde (1.58 g, 9.75 mmol, 1.53 mL) was added acetic acid (100 mL), followed by 3,6-dibromophenanthrene-9,10-dione (3.58 g, 9.75 mmol) and ammonium acetate (9.38 g, 122 mmol, 12.5 equiv.), and the mixture heated at reflux under argon for 2 days. Methanol (20 mL) was added carefully, followed by water until the solution became cloudy. After cooling, the precipitate was collected by vacuum filtration and washed thoroughly with 1:1 water:methanol to give the title compound (6.20 g, 99%) a green powder, .sub.H (CDCl.sub.3, 400 MHz) 1.29 (9H, s), 1.45 (9H, s), 6.96 (1H, d, J=8.9 Hz), 7.30 (2H, app d, J=8.5 Hz), 7.37 (1H, dd, J=1.9 and 8.9 Hz), 7.40 (2H, app. d, J=8.5 Hz), 7.51 (2H, app. d, J=8.5 Hz), 7.61 (2H, app. d, J=8.5 Hz), 7.83 (1H, dd, J=1.7 and 8.5 Hz) and 8.69-8.76 (3H, m); .sub.C (CDCl.sub.3, 100 MHz) 31.16, 31.41, 34.70, 35.07, 119.07, 119.84, 122.01, 122.35, 124.59, 125.25, 125.95, 126.17, 126.84, 127.18, 127.22, 128.00, 128.41, 128.63, 128.88, 129.53, 129.89, 130.87, 135.61, 137.06, 151.67, 152.23 and 153.56.

1,2-Bis[4-(tert-butyl)phenyl]-6,9-di(pyridin-4-yl)-1H-phenanthro[9,10-d]imidazole

[0215] ##STR00093##

[0216] From 6,9-dibromo-1,2-bis-[4-(tert-butyl)phenyl]-1H-phenanthro[9,10-d]imidazole (5.25 g, 8.20 mmol), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (3.53 g, 17.22 mmol, 2.1 equiv.), Pd(PPh.sub.3).sub.4 (0.34 g, 0.287 mmol, 3.5 mol %), and K.sub.2CO.sub.3 (3.74 g, 17.22 mmol, 2.1 equiv.) in degassed PhMe/EtOH (1:1, 120 mL) for 5 days. After extraction and subsequent removal of the solvent the residue was slurried with DCM and passed through silica, followed by MeOH. The solvent was removed in vacuo, the residue triturated with Et.sub.2O, and the resulting solid collected by vacuum filtration and air dried to give the title compound (4.28 g, 82%) as a dark powder. .sub.H (CDCl.sub.3, 400 MHz) 1.31 (9H, s), 1.48 (9H, s), 7.27 (1H, d, J=8.5 Hz), 7.32 (2H, d, J=8.5 Hz), 7.47 (2H, d, J=8.4 Hz), 7.55-7.58 (3H, m), 7.64-7.67 (4H, m), 7.75 (2H, d, J=6 Hz), 8.01 (1H, dd, J=1.2 and 8.3 Hz), 8.72 (2H, d, J=6 Hz), 7.76 (2H, d, J=6 Hz), 8.95-9.03 (3H, m); .sub.C (CDCl.sub.3, 100 MHz) 31.18, 31.45, 34.73, 35.11, 121.74, 121.78, 121.81, 122.02, 122.48, 123.70, 123.95, 125.29, 125.33, 126.32, 127.20, 127.36, 127.92, 128.39, 128.50, 128.57, 128.92, 129.28, 134.30, 135.29, 135.80, 137.70, 148.25, 148.84, 150.41, 150.42, 151.97, 152.27 and 153.55 Compound 15: 4,4-([1,2-bis(4-(tert-Butyl)phenyl]-3-methyl-1H-phenanthro[9,10-d]imidazole-3-ium-6,9-diyl)bis(1-methylpyridin-1-ium) tris(tetrafluoroborate)

##STR00094##

[0217] A mixture of 1,2-bis[4-(tert-butyl)phenyl]-6,9-di(pyridin-4-yl)-1H-phenanthro[9,10-d]imidazole (1.27 g, 2.0 mmol) and MeOTs (3.36 g, 18 mmol, 9.0 equiv.) was heated to 180 C. whilst stirring under argon for 8 hours, cooled, triturated with Et.sub.2O, and the solid collected by vacuum filtration to give a grey powder (2.75 g). A mixture of the crude product (1.17 g) and MeOTs (3.6 g) was heated to 180 C. whilst stirring under argon for 32 hours, cooled, triturated with Et.sub.2O, and the solid collected by vacuum filtration. A filtered solution of the solid in hot 1:1 MeOH:water was added dropwise whilst stirring to a solution of NaBF.sub.4 (2.64 g, 24 mmol, 12.0 equiv) in water (25 mL) to give the title compound (0.71 g, 36%) as a green powder, .sub.H (DMSO-d.sub.6, 400 MHz) 1.28 (9H, s), 1.35 (9H, s), 4.39 (3H, s), 4.45 (6H, bs), 7.19 (1H, d, J=8.8 Hz), 7.59-7.77 (9H, m), 8.26 (1H, dd, J=1.5 and 8.9 Hz), 8.65 (1H, dd, J=1.5 and 8.9 Hz), 8.85 (2H, app. d, J=7 Hz), 8.95 (2H, app. d, J=6.7 Hz), 9.10-9.22 (5H, m), 9.88 (1H, d, J=1.5 Hz) and 9.93 (1H, d, J=1.6 Hz). .sub.F (DMSO-d.sub.6, 376 MHz) 148.26 and 148.21; .sub.C (DMSO-d.sub.6, 100 MHz) 31.17, 31.39, 35.40, 38.42, 47.76, 47.83, 118.83, 122.65, 122.76, 123.48, 124.70, 125.48, 125.64, 125.78, 126.23, 126.36, 127.19, 127.65, 127.90, 128.27, 128.42, 128.53, 130.25, 130.36, 131.57, 132.61, 133.41, 133.51, 138.02, 146.12, 146.25, 151.71, 153.58, 153.72, 155.16 and 155.90.

Example 16

[0218] ##STR00095##

[0219] To a stirred mixture of 4-tert-butylaniline (2.20 g, 14.6 mmol, 2.35 mL, 1.5 equiv.) and 4-tert-butylbenzaldehyde (1.58 g, 9.75 mmol, 1.53 mL) was added acetic acid (100 mL), followed by 2,7-dibromophenanthrene-9,10-dione (3.58 g, 9.75 mmol) and ammonium acetate (9.38 g, 122 mmol, 12.5 equiv.), and the mixed heated under reflux under argon for 2 days. Methanol (20 mL) was added carefully, followed by water until the solution became cloudy. After cooling, the precipitate was collected by vacuum filtration and washed with 1:1 water:methanol to give a tan powder. The crude material was purified by column chromatography (neat DCM) to give the title compound (2.74 g, 44%) an off-white powder, .sub.H (CDCl.sub.3, 400 MHz) 1.30 (9H, s), 1.47 (9H, s), 6.91 (1H, d, J=1.9 Hz), 7.33 (2H, d, J=8.5 Hz), 7.41 (2H, d, J=8.3 Hz), 7.52 (1H, dd, J=1.9 and 8.7 Hz), 7.62 (2H, d, J=8.5 Hz), 7.66 (2H, d, J=8.3 Hz), 7.69 (1H, dd, J=2 and 9 Hz), 8.42 (1H, d, J=8.7 Hz), 8.47 (1H, d, J=9 Hz) and 9.00 (1H, d, J=2 Hz); .sub.C (CDCl.sub.3, 100 MHz) 31.17, 31.43, 34.73, 35.12, 120.83, 122.00, 123.76, 124.26, 124.76, 125.36, 125.41, 125.35, 127.05, 127.16, 127.22, 127.34, 127.76, 127.92, 128.38, 128.58, 128.79, 128.84, 135.41, 137.02, 151.40, 152.31 and 153.90.

1,2-Bis[4-(tert-butyl)phenyl]-5,10-di(pyridin-4-yl)-1H-phenanthro[9,10-d]imidazole

[0220] ##STR00096##

[0221] From 5,10-dibromo-1,2-bis[4-(tert-butyl)phenyl]-1H-phenanthro[9,10-d]imidazole (2.63 g, 4.10 mmol), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (1.77 g, 8.61 mmol, 2.1 equiv.), Pd(PPh.sub.3).sub.4 (0.17 g, 0.14 mmol, 3.5 mol %), and K.sub.2CO.sub.3 (1.87 g, 8.61 mmol, 2.1 equiv.) in degassed PhMe/EtOH (1:1, 80 mL) for 5 days. After extraction and subsequent removal of solvent, the solid was crystallised from hot PhMe to give the title compound (1.33 g, 51%) as a green powder, .sub.H (CDCl.sub.3, 400 MHz) 1.31 (9H, s), 1.49 (9H, s), 7.22 (2H, dd, J=1.5, 4.6 Hz), 7.35 (2H, app. d, J=8.5 Hz), 7.50-7.56 (3H, m), 7.60 (2H, app. d, J=8.5 Hz), 7.69 (2H, app. d, J=8.8.5 Hz), 7.80-7.86 (3H, m), 7.95 (1H, dd, J=2, 8.6 Hz), 8.57 (2H, dd, J=1.4, 4.6 Hz), 8.76 (2H, dd, J=1.4, 4.6 Hz), 8.81 (1H, d, J=8.8 Hz), 8.86 (1H, d, J=8.8 Hz), 9.21 (1H, d, J=1.9 Hz); .sub.C (CDCl.sub.3, 100 MHz) 31.17, 31.51, 34.74, 35.13, 119.32, 121.08, 121.22, 121.94, 123.00, 123.78, 124.08, 124.33, 125.17, 125.38, 127.27, 127.32, 128.00, 128.10, 128.24, 128.60, 128.94, 129.05, 135.25, 135.98, 136.95, 137.81, 147.45, 147.93, 150.27, 150.38, 151.60, 152.30 and 153.66.

Compound 16: 4,4-([1,2-Bis(4-(tert-butyl)phenyl]-3-methyl-1H-phenanthro[9,10-d]imidazole-3-ium-5,10-diyl)bis(1-methylpyridin-1-ium) tris(tetrafluoroborate)

[0222] ##STR00097##

[0223] A mixture of 1,2-bis[4-(tert-butyl)phenyl]-5,10-di(pyridin-4-yl)-1H-phenanthro[9,10-d]imidazole (0.50 g, 0.79 mmol) and MeOTs (2.21 g, 11.9 mmol, 15 equiv.) was heated to 180 C. whilst stirring under argon for 24 hours, cooled, triturated with Et.sub.2O, and the solid collected by vacuum filtration. A filtered solution of the solid in hot 4:1 MeOH:H.sub.2O was slowly added to a stirred solution of NaBF.sub.4 (0.78 g, 7.11 mmol, 9.0 equiv.) in water (15 mL) and stirred for 30 minutes. The precipitate was collected by vacuum filtration and washed with water to give the title compound as a green powder (0.65 g, 86%) as a green powder, .sub.H (DMSO-d.sub.6, 400 MHz) 1.27 (9H, s), 1.32 (9H, s), 4.35 (3H, s), 4.43 (3H, s), 4.57 (3H, s), 7.56 (1H, d, J=1.7 Hz), 7.63 (2H, d, J=8.5 Hz), 8.69-7.82 (6H, m), 7.98 (2H, d, J=6.8 Hz), 8.44 (1H, dd, J=1.7 and 8.8 Hz), 8.60 (1H, dd, J=1.3 and 8.8 Hz), 8.88 (2H, d, J=6.8 Hz), 8.96 (2H, d, J=6.8 Hz), 9.17 (2H, d, J=6.8 Hz), 9.28 (1H, d, J=1.2 Hz), 9.47-9.57 (2H, m); .sub.F (DMSO-d.sub.6, 376 MHz) 148.25 and 148.2; .sub.C (DMSO-d.sub.6, 100 MHz) 31.16, 31.52, 35.40, 35.41, 38.06, 47.83, 47.89, 118.85, 121.13, 121.70, 122.46, 123.15, 124.81, 125.76, 125.90, 126.38, 126.92, 127.30, 127.65, 127.80, 127.87, 127.95, 128.38, 128.67, 131.03, 131.32, 131.61, 132.63, 134.18, 134.99, 146.26, 151.19, 153.50, 153.72, 155.16 and 155.89.

Example 17

6,9-Dibromo-1-[4-(tert-butyl)phenyl]-2-(pyridin-4-yl)-1H-phenanthro[9,10-d]imidazole

[0224] ##STR00098##

[0225] To a stirred mixture of 4-pyridinecarboxaldehyde (1.04 g, 9.75 mmol, 0.91 mL) and 4-tert-butylaniline (2.20 g, 14.6 mmol, 2.35 mL, 1.5 equiv.) was added acetic acid (100 mL), followed by 3,6-dibromophenanthrene-9,10-dione (3.58 g, 9.75 mmol) and ammonium acetate (9.38 g, 122 mmol, 12.5 equiv.), and the mixture heated under reflux under argon for 3 days. Methanol (20 mL) was added carefully, followed by water until the solution became cloudy. After cooling, the precipitate was collected by vacuum filtration and washed with 1 M K.sub.2CO.sub.3 solution, and air dried to give the title compound (4.76 g, 83%) as a green powder, .sub.H (CDCl.sub.3, 400 MHz) 1.47 (9H, s), 6.99 (1H, d, J=8.9 Hz), 7.37-7.56 (5H, m), 7.66 (2H, d, J=8.5 Hz), 7.84 (1H, dd, J=1.8 and 8.5 Hz), 8.54 (2H, d, J=6.2 Hz) and 8.65-8.75 (3H, m); .sub.C (CDCl.sub.3, 100 MHz) 154.42, 149.94, 148.27, 137.89, 137.36, 134.98, 131.13, 130.17, 129.05, 128.82, 128.24, 128.10, 127.59, 126.99, 126.06, 125.31, 124.51, 122.74, 122.47, 121.71, 120.39, 119.91, 35.19 and 31.40.

1-[4-(tert-Butyl)phenyl]-2,6,9-tri(pyridin-4-yl)-1H-phenanthro[9,10-d]imidazole

[0226] ##STR00099##

[0227] From 6,9-dibromo-1-(4-(tert-butyl)phenyl)-2-(pyridin-4-yl)-1H-phenanthro[9,10-d]imidazole (2.93 g, 5.00 mmol), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (2.15 g, 10.5 mmol, 2.1 equiv.), Pd(PPh.sub.3).sub.4 (0.20 g, 0.18 mmol, 3.5 mol %), and K.sub.2CO.sub.3 (1.45 g, 10.5 mmol, 2.1 equiv.) in degassed PhMe/EtOH (1:1, 120 mL) for 6 days. After extraction and subsequent removal of solvent, the residue was triturated with water (250 mL), then triturated with Et.sub.2O (50 mL). The resulting solid was dissolved in hot 10:1 PhMe:EtOH, cooled to 20 C. overnight, then concentrated in vacuo. The resulting precipitate was collected by vacuum filtration and washed with Et.sub.2O to give the title compound (1.50 g, 52%) as a tan powder, .sub.H (CDCl.sub.3, 400 MHz) 1.50 (9H, s), 7.31 (1H, d, J=8.7 Hz), 7.48-7.51 (4H, m), 7.56-7.77 (7H, m), 8.04 (1H, dd, J=1.2 and 8.4 Hz), 8.56 (2H, d, J=6.1 Hz), 8.73 (2H, d, 6 Hz), 8.76 (2H, d, J=6 Hz), 8.94-9.05 (3H, m); .sub.C (CDCl.sub.3, 100 MHz) 31.43, 35.22, 121.81, 121.85, 122.01, 122.03, 122.60, 122.82, 123.38, 123.91, 125.62, 126.62, 127.61, 127.67, 128.19, 128.64, 129.29, 129.82, 135.12, 135.90, 137.63, 137.92, 148.05, 148.61, 149.95, 150.44, 150.47 and 154.42.

Compound 17: 4,4,4-{[1-(4-(tert-Butyl)phenyl]-3-methyl-1H-phenanthro[9,10-d]imidazole-3-ium-2,6,9-triyl}tris(1-methylpyridin-1-ium) tetrakis(tetrafluoroborate)

[0228] ##STR00100##

[0229] A mixture of 1-[4-(tert-butyl)phenyl]-2,6,9-tri(pyridin-4-yl)-1H-phenanthro[9,10-d]imidazole (1.17 g, 2.0 mmol) and MeOTs (2.60 g, 14 mmol, 7.0 equiv.) was heated to 180 C. whilst stirring under argon for 16 hours, cooled, triturated with Et.sub.2O, and the solid collected by vacuum filtration. The solid was ground with a pestle and mortar along with a small amount of Et.sub.2O, triturated with Et.sub.2O, and air drive to give a green-yellow powder. A mixture of the powder (1.55 g) and MeOTs (1.0 g, 5.4 mmol) was heated to 180 C. whilst stirring under argon for 16 hours, cooled, triturated with Et.sub.2O, and the solid collected by vacuum filtration. A filtered solution of the solid in hot MeOH:water (1:1) was added dropwise to a stirred solution of NaBF.sub.4 (2.64 g, 24.0 mmol, 12.0 equiv.) in water (25 mL), stirred for 30 minutes, and the precipitate collected by vacuum filtration to give the title compound (0.71 g, 36%) as a green powder, .sub.H (DMSO-d.sub.6, 400 MHz) 1.38 (9H, s), 4.39 (3H, s), 4.43 (3H, s), 4.45 (3H, s), 4.51 (3H, s), 7.02 (1H, d, J=8.8 Hz), 8.26 (1H, dd, J=1.8 and 8.8 Hz), 8.50 (2H, d, J=6.8 Hz), 8.65 (1H, dd, J=1.8 and 8.8 Hz), 8.84 (2H, d, J=7.1 Hz), 8.95 (2H, d, J=7 Hz), 9.12-9.22 (5H, m), 9.27 (2H, d, J=7 Hz), 9.87 (1H, d, J=1.8 Hz) and 9.93 (1H, d, J=1.8 Hz); .sub.F (DMSO-d.sub.6, 376 MHz) 148.27, 148.22; .sub.C (DMSO-d.sub.6, 400 MHz) 31.41, 35.53, 38.62, 47.81, 47.88, 49.35, 122.24, 122.59, 122.95, 124.97, 125.58, 125.77, 126.37, 127.91, 128.22, 128.36, 128.55, 128.75, 130.62, 130.71, 131.28, 134.02, 134.15, 137.00, 145.64, 146.16, 146.28, 147.59, 153.41, 153.58 and 156.09.

Example 18

6,9-Dibromo-1-[4-(tert-butyl)phenyl]-2-(pyridin-4-yl)-1H-phenanthro[9,10-d]imidazole

[0230] ##STR00101##

[0231] To a stirred mixture of 4-tert-butylaniline (2.20 g, 14.6 mmol, 2.35 mL, 1.5 equiv.) and 4-bromobenzaldehyde (1.80 g, 9.75 mmol) was added acetic acid (100 mL), followed by 3,6-dibromophenanthrene-9,10-dione (3.58 g, 9.75 mmol) and ammonium acetate (9.38 g, 122 mmol, 12.5 equiv.), and the mixture heated under reflux under argon for 2 days. Methanol (20 mL) was added carefully, followed by water until the solution became cloudy. After cooling, the precipitate was collected by vacuum filtration and washed with 1:1 water:methanol to give the title compound (6.10 g, 94%) as a green powder, .sub.H (CDCl.sub.3, 400 MHz) 1.45 (9H, s), 6.97 (1H, d, J=8.9 Hz), 7.34-7.44 (7H, m), 7.61 (2H, d, J=8.4 Hz), 7.82 (1H, dd, J=1.5 and 8.5 Hz) and 8.64-8.74 (3H, m); .sub.C (CDCl.sub.3, 100 MHz) 31.40, 35.12, 119.40, 120.05, 121.83, 122.34, 123.61, 124.48, 126.00, 126.02, 126.90, 127.37, 128.18, 128.25, 128.68, 129.12, 129.66, 130.01, 130.67, 130.96, 131.49, 135.25, 137.11, 150.33 and 153.93.

1-[4-(tert-Butyl)phenyl]-6,9-di(pyridin-4-yl)-2-[4-(pyridin-4-yl)phenyl]-1H-phenanthro[9,10-d]imidazole

[0232] ##STR00102##

[0233] From 6,9-dibromo-1-[4-(tert-butyl)phenyl]-2-(4-bromophenyl)-1H-phenanthro[9,10-d]imidazole (5.44 g, 8.20 mmol), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (5.30 g, 25.8 mmol, 3.15 equiv.), Pd(PPh.sub.3).sub.4 (0.34 g, 0.38 mmol, 3.5 mol %), and K.sub.2CO.sub.3 (5.61 g, 25.8 mmol, 3.15 equiv.) in degassed PhMe/EtOH (1:1, 120 mL) for 7 days. After extraction and subsequent removal of solvent, the residue was dissolved in hot 1:1 DCM:isopropanol, cooled to 20 C. overnight, then concentrated in vacuo. The resulting precipitate was collected by vacuum filtration and washed with Et.sub.2O to give the title compound (3.73 g, 59%) as a green powder, .sub.H (CDCl.sub.3, 400 MHz) 1.49 (9H, s), 7.32 (1H, d, J=8.6 Hz), 7.48-7.53 (4H, m), 7.57-7.62 (3H, m), 7.64-7.71 (4H, m), 7.73-7.79 (4H, m), 8.06 (1H, dd, J=1.4, 8.3 Hz), 8.67 (2H, dd, J=1.5, 4.6 Hz), 8.73 (2H, dd, J=1.5, 4.6 Hz), 8.77 (2H, dd, J=1.5, 4.6 Hz), 8.98-9.07 (3H, m); .sub.C (CDCl.sub.3, 100 MHz) 31.45, 35.17, 121.46, 121.81, 121.91, 122.05, 122.58, 123.57, 123.93, 125.50, 126.50, 126.84, 127.40, 127.81, 128.23, 128.42, 128.53, 128.87, 129.53, 129.90, 130.98, 134.71, 135.58, 135.62, 137.86, 138.44, 147.30, 148.18, 148.77, 150.38, 150.44, 150.92 and 153.92.

Compound 18: 4,4-{1-[4-(tert-Butyl)phenyl]-3-methyl-2-(4-(1-methylpyridin-1-ium-4-yl)phenyl)-1H-phenanthro[9,10-d]imidazole-3-ium-6,9-diyl}bis(1-methylpyridin-1-ium) tetrakis(tetrafluoroborate)

[0234] ##STR00103##

[0235] A mixture of 1-[4-(tert-butyl)phenyl]-6,9-di(pyridin-4-yl)-2-[4-(pyridin-4-yl)phenyl]-1H-phenanthro[9,10-d]imidazole (3.29 g, 5.0 mmol) and MeOTs (5.59 g, 30 mmol, 6.0 equiv.) was heated to 180 C. whilst stirring under argon for 16 hours, cooled, triturated with Et.sub.2O, and the solid collected by vacuum filtration. The solid was ground with a pestle and mortar along with a small amount of Et.sub.2O, triturated with Et.sub.2O, and air drive to give a green powder. A mixture of the powder (4.91 g) and MeOTs (4.00 g, 21.5 mmol) was heated to 180 C. whilst stirring under argon for 16 hours, cooled, triturated with Et.sub.2O, and the solid collected by vacuum filtration. A filtered solution of the solid in hot 1:1: MeOH:water was added dropwise to a stirred solution of NaBF.sub.4 (6.59 g, 50 mmol, 12.0 equiv.) in water (65 mL), stirred for 30 minutes, and the precipitate collected by vacuum filtration to give the title compound (4.17 g, 78%) as a khaki-green powder, .sub.H (DMSO-d.sub.6, 400 MHz) 1.35 (9H, s), 4.36 (3H, s), 4.39 (3H, s), 4.44 (3H, s), 4.48 (3H, s), 7.09 (1H, d, J=8.8 Hz), 7.75 (2H, d, 8.6 Hz), 7.80 (2H, d, J=8.6 Hz), 8.08 (2H, d, J=8.4 Hz), 8.25 (1H, dd, J=1.7, 8.9 Hz), 8.32 (2H, d, J=8.5 Hz), 8.56 (2H, d, J=6.9 Hz), 8.65 (1H, dd, J=1.7, 8.8 Hz), 8.85 (2H, d, J=7.1 Hz), 8.95 (2H, d, J=7.1, ArH), 9.05-9.27 (7H, m), 9.88 (1H, d, J=1.7 Hz) and 9.95 (1H, d, J=1.7); .sub.F (DMSO-d.sub.6, 376 MHz) 148.25 and 148.20; .sub.C (DMSO-d.sub.6, 100 MHz) 31.41, 35.45, 38.48, 47.78, 47.84, 122.63, 123.35, 124.77, 125.21, 125.51, 125.67, 125.78, 126.30, 127.41, 127.88, 128.17, 128.43, 128.60, 129.09, 130.35, 130.48, 132.33, 133.04, 133.57, 133.69, 137.67, 147.13, 146.27, 146.43, 150.26, 152.92, 153.51, 153.67 and 155.48.

5. Benzoselenazoles

Example 19

4-(Benzoselenazol-2-yl)-1-hexylpyridin-1-ium iodide

[0236] ##STR00104##

[0237] 2-(Pyridin-4-yl)benzoselenazole (0.75 g, 2.89 mmol) and 1-iodohexane (1.23 mL, 8.67 mmol) were suspended in MeCN (40 mL) and then stirred at 80 C. for 16 h. The reaction mixture was cooled to ambient temperature and the solvent was removed under reduced pressure. The resulting solid was triturated with acetone (20 mL), filtered, washed with acetone (20 mL) and dried under reduced pressure to give the desired product as an orange powder. Yield 1.10 g, 81%. .sub.H (CD.sub.3OD, 300 MHz) 9.11 (d, J=6.9 Hz, 2H), 8.68 (d, J=6.9 Hz, 2H), 8.28 (d, J=8.2 Hz, 1H), 8.23 (d, J=8.2 Hz, 1H), 7.65 (dd, J=7.3, 1.2 Hz, 1H), 7.53 (dd, J=7.3, 1.2 Hz, 1H), 4.67 (t, J=7.6, 2H), 1.95 (quint., J=7.4 Hz, 2H), 1.55-1.23 (m, 6H), 0.94 (t, J=6.8 Hz, 3H); .sub.C (DMSO-d.sub.6, 100 MHz) 166.72, 156.98, 151.53, 146.78, 142.04, 128.82, 128.80, 127.52, 126.90, 126.53, 62.87, 32.41, 32.32, 26.91, 23.48, 14.28.

Compound 19: 4-(Benzoselenazol-2-yl)-1-hexylpyridin-1-ium tetrafluoroborate

[0238] ##STR00105##

[0239] 4-(Benzoselenazol-2-yl)-1-hexylpyridin-1-ium iodide (0.65 g, 1.38 mmol) was dissolved in hot MeOH (50 mL) and added dropwise through a cotton wool plug to a stirred solution of NaBF.sub.4 (5.0 g) in H.sub.2O (200 mL) whereupon a pale yellow precipitate formed. The solution was stirred for 30 minutes and then filtered under reduced pressure. The resulting solid was washed with water (30 mL) and then dried under reduced pressure to give the desired product as a pale yellow powder. Yield 0.59 g, 76%. .sub.H (DMSO-d.sub.6, 400 MHz) 9.20 (d, J=6.7 Hz, 2H), 8.74 (d, J=6.7 Hz, 2H), 8.39 (d, J=8.0 Hz, 1H), 8.28 (d, J=8.0 Hz, 1H), 7.66 (dd, J=7.3, 0.9 Hz, 1H), 7.55 (dd, J=7.3, 0.9 Hz, 1H), 4.64 (t, J=7.4, 2H), 1.95 (quint., J=6.5 Hz, 2H), 1.43-1.20 (m, 6H), 0.87 (t, J=6.7 Hz, 3H); .sub.C (DMSO-d.sub.6, 100 MHz) 166.57, 154.99, 148.64, 145.71, 140.40, 127.61, 127.34, 126.49, 125.91, 125.21, 60.57, 30.68, 30.56, 25.05, 21.84, 13.81; .sup.6B (DMSO-d.sub.6, 128 MHz) 1.3; .sub.F (DMSO-d.sub.6, 376 MHz) 148.27 (br. m, 4F).

Example 20

4-(Benzoselenazol-2-yl)-1-phenylpyridin-1-ium trifluoromethanesulfonate

[0240] ##STR00106##

[0241] 2-(Pyridin-4-yl)benzoselenazole (1.00 g, 3.86 mmol), diphenyliodonium triflate (2.49 g, 5.79 mmol) and Cu(OAc).sub.2. H.sub.2O (116 mg, 0.58 mmol) were dissolved in DMF (30 mL) under N.sub.2 and the reaction mixture was stirred at 100 C. for 16 h. The reaction mixture was cooled to room temperature and the solvent was removed under reduced pressure. The resulting yellow solid was triturated in hot MeOH, filtered and dried under reduced pressure to give the desired product as a yellow powder. Yield 1.70 g, 91%. .sub.H (DMSO-d.sub.6, 400 MHz) 9.46 (d, J=6.9 Hz, 2H), 8.86 (d, J=6.9 Hz, 2H), 8.42 (d, J=7.8 Hz, 1H), 8.33 (d, J=7.8 Hz, 1H), 8.00-7.90 (m, 2H), 7.84-7.74 (m, 3H), 7.69 (dd, J=7.4, 1.1 Hz, 1H), 7.58 (dd, J=7.4, 1.1 Hz, 1H); .sub.C (DMSO-d.sub.6, 100 MHz) 166.28, 155.14, 149.35, 145.83, 142.39, 140.80, 131.40, 130.24, 127.75, 127.55, 126.60, 126.14, 124.97, 124.68, 120.65 (d, J.sub.C-F=320.4 Hz); .sub.F (DMSO-d.sub.6, 376 MHz) 77.76 (s, 3F).

Compound 20: 4-(Benzoselenazol-2-yl)-1-phenylpyridin-1-ium tetrafluoroborate

[0242] ##STR00107##

[0243] 4-(Benzoselenazol-2-yl)-1-phenylpyridin-1-ium trifluoromethanesulfonate (1.00 g, 2.06 mmol) was dissolved in hot MeOH (50 mL) and added dropwise through a cotton wool plug to a stirred solution of NaBF.sub.4 (5.0 g) in H.sub.2O (200 mL) whereupon a yellow precipitate formed. The solution was stirred for 30 minutes and then filtered under reduced pressure. The resulting solid was washed with water (30 mL) and then dried under reduced pressure to give the desired product as a yellow powder. Yield 0.61 g, 70%. .sub.H (DMSO-d.sub.6, 400 MHz) 9.45 (d, J=6.9 Hz, 2H), 8.55 (d, J=6.9 Hz, 2H), 8.41 (d, J=7.8 Hz, 1H), 7.32 (d, J=7.8 Hz, 1H), 8.00-7.87 (m, 2H), 7.83-7.72 (m, 3H), 7.67 (dd, J=7.4, 1.1 Hz, 1H), 7.57 (dd, J=7.4, 1.1 Hz, 1H); .sub.C (DMSO-d.sub.6, 100 MHz) 166.30, 155.16, 149.36, 145.84, 142.40, 140.82, 131.43, 130.27, 127.77, 127.57, 126.61, 126.16, 124.99, 124.69; .sup.6b (DMSO-d.sub.6, 128 MHz) 1.3; S.sub.F (DMSO-d.sub.6, 376 MHz) 148.21 (br. m, 4F).

Example 21

Compound 21: 4-(Benzoselenazol-2-yl)-1-phenylpyridin-1-ium hexafluorophosphate

[0244] ##STR00108##

[0245] 4-(Benzoselenazol-2-yl)-1-phenylpyridin-1-ium trifluoromethanesulfonate (0.20 g, 0.47 mmol) was dissolved in hot MeOH (20 mL) and added dropwise through a cotton wool plug to a stirred solution of NH.sub.4PF.sub.6 (0.50 g) in H.sub.2O (100 mL) whereupon a yellow precipitate formed. The solution was stirred for 30 minutes and then filtered under reduced pressure. The resulting solid was washed with water (30 mL) and then dried under reduced pressure to give the desired product as a yellow powder. Yield 0.13 g, 71%. .sub.H [(CD.sub.3).sub.2CO, 400 MHz] 9.52 (d, J=6.3 Hz, 2H), 8.98 (d, J=6.3 Hz, 2H), 8.38 (d, J=8.5 Hz, 1H), 8.36 (d, J=8.5 Hz, 1H), 8.13-7.95 (m, 2H), 7.92-7.78 (m, 3H), 7.73 (t, J=7.6 Hz, 1H), 7.61 (t, J=7.6 Hz, 1H); .sub.C [(CD.sub.3).sub.2CO, 100 MHz] 166.22, 156.65, 151.54, 146.67, 143.78, 141.91, 132.64, 131.45, 128.74, 128.71, 127.39, 126.99, 126.34, 125.43; .sub.P [(CD.sub.3).sub.2CO, 162 MHz] 144.27 (sept., J=707.8 Hz, 1P); .sub.F [(CD.sub.3).sub.2CO, 376 MHz] 72.51 (d, J=707.8 Hz, 6F).

6. Benzoxazoles and Benzoisoxazoles

Example 22

2-(Pyridin-4-yl)-2,3-dihydrobenzoxazole

[0246] ##STR00109##

[0247] A solution of 2-aminophenol (8.00 g, 73.4 mmol) and pyridine-4-carboxaldehyde (7.85 g, 73.4 mmol) in EtOH (350 mL) was stirred under air for 5 days. The solvent was reduced in volume and the resulting solid filtered off, washed with EtOH (20 mL) and air dried to give the title compound (13.36 g, 92%) as an orange powder, .sub.H (CDCl.sub.3, 400 MHz) 6.93 (1H, app. t, J=7.7 Hz), 7.04 (1H, app. d, J=8.1 Hz), 7.22-7.31 (2H, m), 7.35 (1H, app. d, J=8.0 Hz), 7.76 (2H, bd, J=4.5 Hz), 8.69 (1H, s) and 8.78 (2H, bs).

2-(Pyridin-4-yl)benzoxazole

[0248] ##STR00110##

[0249] 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (1.15 g, 5 mmol) was added in one portion to a solution of 2-(pyridin-4-yl)-2,3-dihydrobenzoxazole (1.00 g, 5 mmol) in DCM (50 mL) with stirring. Stirring was continued for 1 h and Et.sub.3N (5 mL) was added. The resulting solution was filtered through silica using DCM (100-0% in EtOAc) as eluent. The first band was collected to give the title compound (0.43 g, 43%) as a pale yellow powder. The second band was collected to give unreacted starting material (0.28 g, 28%), .sub.H (CDCl.sub.3, 400 MHz) 7.39-7.47 (2H, m), 7.61-7.66 (1H, m), 7.81-7.85 (1H, m), 8.10 (2H, dd, J=1.6 and 4.6 Hz) and 8.83 (2H, dd, J=1.6 and 4.6 Hz).

4-(Benzoxazol-2-yl)-1-hexylpyridin-1-ium iodide

[0250] ##STR00111##

[0251] A solution of 2-(pyridin-4-yl)benzoxazole (1.00 g, 5.1 mmol) and 1-iodohexane (3.24 g, 15.3 mmol) in MeCN (30 mL) was heated at reflux in the dark under N.sub.2 with stirring. After 16 h, the resulting mixture was cooled and diluted with Et.sub.2O (50 mL). The precipitate was filtered off, washed with Et.sub.2O (310 mL) and air dried to give the title compound (2.06 g, 99%) as a yellow powder.

Compound 22: 4-(Benzoxazol-2-yl)-1-hexylpyridin-1-ium tetrafluoroborate

[0252] ##STR00112##

[0253] A solution of 4-(benzoxazol-2-yl)-1-hexylpyridin-1-ium iodide (2.01 g, 4.9 mmol) in warm MeOH/water (50 mL, 1:1) was added dropwise to a solution of NaBF.sub.4 (5.42 g, 40 mmol) in water (100 mL) with stirring. Stirring was continued for 0.5 h and the resulting precipitate filtered off, washed with water (310 mL) and air dried to give the title compound (1.77. g, 98%) as a colourless powder, .sub.H (CD.sub.3OD, 400 MHz) 0.89-0.97 (3H, bt, J=5.7 Hz), 1.30-1.51 (6H, m), 2.00-2.14 (2H, m), 4.69 (2H, bt, J=7.4 Hz), 7.50-7.65 (2H, bm), 7.83 (1H, bd, J=8.2 Hz), 8.93 (1H, bd, J=8 Hz), 8.78 (2H, bd, J=5.5 Hz) and 9.16 (2H, bd, J=5.5 Hz).

Example 23

4-(Benzoxazol-2-yl)-1-phenylpyridin-1-ium triflate

[0254] ##STR00113##

[0255] A mixture of 2-(pyridin-4-yl)benzoxazole (1 g, 5.1 mmol), diphenyliodonium triflate (3.29 g, 7.6 mmol), Cu(OAc).sub.2.Math.H.sub.2O (100 mg, 10 mol %) in dry DMF (50 mL) was heated at 100 C. for 16 h, cooled and the solvent removed under reduced pressure. The residue was triturated with Et.sub.2O (50 mL), washed with Et.sub.2O (310 mL) and air dried. The resulting solid was triturated with hot MeOH (20 mL), cooled, filtered and air dried to give the title compound (1.86 g, 86%) as a colourless powder, .sub.H (CD.sub.3OD, 400 MHz) 7.54-7.70 (2H, bm), 7.76-8.00 (7H, bm), 8.93 (2H, bd, J=5.9 Hz) and 9.42 (2H, bd, J=5.9 Hz).

Compound 23: 4-(Benzoxazol-2-yl)-1-phenylpyridin-1-ium tetrafluoroborate

[0256] ##STR00114##

[0257] A solution of 4-(benzoxazol-2-yl)-1-phenylpyridin-1-ium triflate (0.25 g, 0.59 mmol) in warm MeOH (10 mL) was added dropwise to a solution of NaBF.sub.4 (0.65 g, 5.9 mmol) in water (30 mL) with stirring. The resulting precipitate was filtered, washed with water (23 mL), dissolved in warm MeOH (10 mL) and added dropwise to a solution of NaBF.sub.4 (0.65 g, 5.9 mmol) in water (30 mL) and stirred for 0.5 h. The resulting precipitate was filtered off, washed with water (23 mL) and air dried to give the title compound (0.20 g, 95%) as a pale yellow powder, .sub.H (DMSO-d.sub.6, 400 MHz) 7.56-7.62 (1H, m), 7.64-7.70 (1H, m), 7.74-7.82 (3H, m), 7.91-8.01 (3H, m), 8.05 (1H, d, J=7.9 Hz), 8.87 (2H, bd, J=6.8 Hz) and 9.53 (2H, bd, J=6.8 Hz).

Example 24

4-(2-Methoxybenzoyl)pyridine

[0258] ##STR00115##

[0259] A freshly prepared solution of 2-methoxyphenylmagnesium bromide (40 mL, ca. 1.38 M, 55.4 mmol) was added to a stirred solution of 4-cyanopyridine (2.78 g, 26.7 mmol) in dry THF (20 mL) which had been cooled to 0 C. under N.sub.2. After the addition was complete the reaction mixture was stirred and heated at 50 C. under N.sub.2 for 16 h. The solution was then cooled to 0 C. and H.sub.2O (20 mL) was slowly added. The reaction mixture was then evaporated to dryness under reduced pressure and then 2M HCl (100 mL) was added, and the solution was heated at 80 C. for 8 h. The reaction mixture was then cooled to room temperature and the solution was washed with EtOAc (2100 mL). The aqueous phase was basified with NaOH (5 M) and extracted with DCM (3100 mL). The organic layers were combined, dried (Na.sub.2SO.sub.4), filtered and the solvent was removed under reduced pressure. The resulting residue was chromatographed on silica gel [eluent=1:9 graduated to 1:1 EtOAc:Petroleum ether]. The solvent of the resulting column fractions was removed under reduced pressure to give the title compound as a yellow oil. Yield 4.60 g, 82%. .sub.H (CDCl.sub.3, 400 MHz) 8.75 (2H, dd, J=4.4, 1.6 Hz), 7.57-7.51 (3H, m), 7.46 (1H, dd, J=7.6, 1.8 Hz), 7.07 (1H, td, J=7.55, 0.9 Hz), 6.99 (1H, d, J=8.3 Hz) and 3.68 (3H, s); .sub.C (CDCl.sub.3, 100 MHz) 195.6, 158.0, 150.5, 144.8, 133.5, 130.5, 127.3, 122.4, 121.0, 111.7 and 55.6.

3-(Pyridin-4-yl)-1,2-benzisoxazole

[0260] ##STR00116##

[0261] 4-(2-Methoxybenzoyl)pyridine (3.60 g, 16.8 mmol) was dissolved in dry DCM (100 mL) and cooled to 0 C. under N.sub.2. BBr.sub.3 (8.42 g, 3.24 mL, 33.6 mmol) was added dropwise and the reaction mixture was stirred for 16 h. The reaction mixture was added to ice, neutralized with NaHCO.sub.3 and stirred for 1 h. The reaction mixture was then extracted with DCM (2200 mL) and the organic layers were combined, dried (Na.sub.2SO.sub.4), filtered, and the solvent removed under reduced pressure. The resulting residue was chromatographed on silica gel [eluent=1:9 graduated to 4:6 EtOAc:Petroleum ether]. The solvent of the resulting column fractions was removed under reduced pressure to give impure 4-(2-hydroxybenzoyl)pyridine (2.60 g) as a yellow solid which was used in the subsequent reactions without further purification. The impure 4-(2-hydroxybenzoyl)pyridine (2.60 g) was dissolved in 7N ammonia in methanol (30 mL) and stirred at room for 48 h to give an orange coloured solution. The reaction mixture was then evaporated to dryness under reduced pressure and redissolved in dry THF (40 mL) under N.sub.2. N-Chlorosuccinimide (2.60 g, 19.5 mmol) and K.sub.2CO.sub.3 (3.60 g, 138 mmol) were then added to the reaction mixture which was then stirred for 16 h at room temperature under N.sub.2. The reaction mixture was then diluted with diethyl ether (100 mL) and quenched with water (100 mL). The organic layer was separated and the aqueous layer was extracted with diethyl ether (2100 mL). The organic layers were combined, dried (Na.sub.2SO.sub.4), filtered and the solvent removed under reduced pressure. The resulting residue was chromatographed on silica gel [eluent=1:9 graduated to 3:7 EtOAc:petroleum ether]. The solvent of the resulting column fractions was removed under reduced pressure to give a pale yellow solid that was then triturated with pentane and dried under reduced pressure to give the title compound as an off-white solid. Yield 1.2 g, 36%. .sub.H (CDCl.sub.3, 400 MHz) 8.84 (2H, dd, J=4.5, 1.5 Hz), 7.95 (1H, dt, J=8.0, 0.9 Hz), 7.89 (2H, dd, J=4.4, 1.6 Hz) 7.70 (1H, dt, J=8.4, 0.8 Hz), 7.67 (1H, ddd, J=8.5, 7.0, 1.0 Hz) and 7.44 (1H, ddd, J=8.5, 7.0, 1.0 Hz); .sub.C (CDCl.sub.3, 100 MHz) 164.3, 155.4, 150.9, 136.7, 130.4, 124.6, 122.3, 1217, 119.9, 110.6.

Compound 24: 4-(1,2-Benzisoxazol-3-yl)-1-phenylpyridin-1-ium hexafluorophosphate

[0262] ##STR00117##

[0263] 3-(Pyridin-4-yl)-1,2-benzisoxazole (1.00 g, 5.1 mmol) diphenyliodonium trifluoromethanesulfonate (3.29 g, 7.64 mmol) and Cu(OAc).sub.2. H.sub.2O (0.1 g, 0.51 mmol) were dissolved in DMF (40 mL) under N.sub.2 and the reaction mixture was stirred at 100 C. for 16 h. The reaction mixture was cooled to room temperature and the solvent was removed under reduced pressure. The resulting pale green solid was triturated with diethyl ether (350 mL), filtered and dried under reduced pressure. The resulting hydroscopic pale green solid was dissolved in hot MeOH:H.sub.2O (ca. 2:1, 150 mL) and added dropwise through a cotton wool plug to a stirred solution of NH.sub.4PF.sub.6 (17.5.0 g) in H.sub.2O (350 mL) whereupon a pale yellow precipitate formed. The suspension was stirred for 30 minutes and then filtered under reduced pressure. The resulting solid was washed with water (50 mL) and then dried under reduced pressure to give a pale green powder. The solid was then dissolved in hot acetone:H.sub.2O (ca. 2:1, 200 mL) and added dropwise through a cotton wool plug back into the filtrate (which had been reduced by ca. 20% under vacuum) to give a pale green precipitate. The resulting suspension was then filtered under reduced pressure and the solid was washed with water (50 mL) and then dried under reduced pressure to give a pale green powder. The green powder was triturated with MeOH (50 mL), filtered and dried under reduced pressure to give the title compound as a colourless powder. Yield 1.17 g, 55%. .sub.H (DMSO-d.sub.6, 400 MHz) 9.60 (2H, d, J=7.0 Hz), 8.96 (2H, d, J=6.9 Hz), 8.43 (1H, d, J=8.1 Hz), 8.09 (1H, d, J=8.6 Hz) 8.05-7.98 (2H, m), 7.93 (1H, ddd, J=8.5, 7.1, 1.0 Hz), 7.89-7.79 (3H, m) and 7.72 (1H, ddd, J=8.5, 7.3, 0.5 Hz); .sub.C (DMSO-d.sub.6, 100 MHz) 164.1, 153.3, 146.0, 144.1, 142.5, 131.6, 131.5, 130.3, 126.2, 125.8, 124.8, 122.4, 118.6 and 110.7; .sub.F (DMSO-d.sub.6, 376 MHz) 170.13 (6F, d, J=711.0 Hz).

Evaluation of Oxido-Reduction Potentials and Absorption Spectra of the Compounds of the Invention

Method for Measuring Oxido-Reduction Potentials

[0264] The oxido-reduction potentials of the compounds are measured by cyclic voltammetry with 3 electrodes.

[0265] The 3 electrodes used are: [0266] 1 Platinum working electrode [0267] 1 Platinum auxiliary or counter electrode [0268] 1 Platinum reference electrode which is immersed into a solution constituted of 0.01 M AgNO.sub.3+0.1 M TBAP (tetrabutylammonium perchlorate) in acetonitrile.

[0269] The scan rate of the potential is fixed to 100 mV/s.

[0270] E.sub.1.sup.red corresponds to the first reduction peak of the analyzed compound.

[0271] E.sub.2.sup.red corresponds to the second reduction peak of the analyzed compound.

[0272] E.sub.1.sup.1/2 corresponds to the oxido-reduction potential of an oxidant/reductor system as calculated below:

E.sub.1.sup.1/2=(E.sub.1.sup.red+E.sub.1.sup.ox)/2

wherein E.sub.1.sup.ox corresponds to the first oxidation peak of the analyzed compound.

[0273] E.sup.red corresponds to the difference between E.sub.1.sup.red and E.sub.2.sup.red as calculated below: E.sub.red=|E.sub.2.sup.red||E.sub.1.sup.red|.

[0274] The indicated potential values are the first reduction potentials for the compounds, with respect to the standard hydrogen reference electrode (SHE).

[0275] The analyzed solution comprises 0.005 M of the compound to be analyzed and 0.25 M of TBABF.sub.4 salt in propylene carbonate as solvent.

Method for Measuring Absorption Spectra

[0276] This solution is introduced into a quartz cell where.

[0277] This solution is introduced into a quartz cell where at least one working electrode in the form of a platinum grid is placed to colour the analysed compound on this electrode. The absorption spectrum of the analysed compound in the time domain is measured by uv-visible spectroscopy.

[0278] The results for each of the synthesized compounds are indicated in Table 1 below. E.sub.1.sup.red corresponds to the first reduction potential. The colour indicated in Table 1 is the visual colour perceived by emmetropic eyes under day light conditions. It should be noted that the .sub.max value just gives an approximate indication of the colour of a particular compound. However, as a consequence of the broad nature of the absorption bands, the whole absorption spectrum has to be taken into account in order to understand the final perceived colour of any one compound.

[0279] In comparison, Table 2 shows the results obtained for 3 known compounds.

[0280] By comparing compound 2 (orange) and compounds 6-7 (red) of the invention with known compound COMP1 (green), it appears that replacing one phenyl pyridinium group by one substituted benzimidazolium or substituted benzothiazolium group reduces the maximum absorption wavelength in the visible range from 645 nm to 550 nm or below. At their activated state these molecules are red or orange rather than green.

[0281] By comparing compounds 1, 10, 16 (orange), 3, 4, 5 (purple), 8 (green), 9, 11 (yellow/green), 13-14 (yellow), with known compounds COMP2 (blue) and COMP3 (blue), it appears that including different groups like imidazolium, benzimidazolium, benzothiazolium, alone or included in more complex molecular structures have also this effect of shifting the maximum absorption wavelength to lower values. These groups can be either introduced in between two alkyl bi pyridinium groups or could replace the central pyridinium group of a ter pyridinium. The molecules thus obtained are yellow, orange, red, green or purple rather than blue.

[0282] The results show that the known compound COMP3, which contains a phenyl group in between two alkyl bi pyridinium groups, is also orange with an activation potential of 1.21V. The compounds of the invention have a similar or lower activation potential than COMP3, except compounds 11 and 14.

TABLE-US-00002 TABLE 1 E.sub.1.sup.red E1 peak E.sub.2.sup.red E2 peak E.sub.1 .sup.1/2 1 2 cut peak potential peak potential E.sub.1 .sup.1/2 (V) reversi- max max (nm) potential (V) vs potential (V) vs Cpd Structure (V) vs SHE bility color (nm) (nm) clear (V) SHE (V) SHE E.sup.red 1 [00118] 0.62 0.078 Y orange 421 530 399 0.65 0.108 0.92 0.378 0.27 2 [00119] 0.53 0.012 Y orange 446 550 435 0.57 0.028 0.78 0.238 0.21 3 [00120] NA N purple 390 wide absorb- tion 380 1 0.458 NA NA 4 [00121] 0.98 0.438 Y purple 390 525 382 1 0.458 1.35 0.808 0.35 5 [00122] NA N purple 402 530 373 0.48 0.062 0.86 0.318 0.38 6 [00123] 0.8 0.258 Y red 416 530 397 0.87 0.328 1.22 0.678 0.35 7 [00124] 0.82 0.278 Y red 415 530 393 0.9 0.358 1.24 0.698 0.34 8 [00125] 1.07 0.528 Y green 437 650 473 1.1 0.558 1.5 0.958 0.4 9 [00126] 1.2 0.658 Y yellow 412 412 1.24 0.698 1.65 1.108 0.41 10 [00127] 0.96 0.418 Y orange 470 580 0.542 0.542 0 11 [00128] 1.39 0.848 Y green 410 640 450 1.45 0.908 NA NA 12 [00129] 1.27 0.728 Y orange 486 750 439 1.32 0.778 NA NA 13 [00130] 0.542 N yellow 443 650 456 0.98 0.438 1.48 0.938 0.5 14 [00131] 1.4 0.858 Y yellow 409 750 426 1.53 0.988 NA NA 15 [00132] 1.12 0.578 Y red 533 437 1.15 0.608 NA NA 16 [00133] 0.94 0.398 Y red 541 458 1.02 0.478 NA NA 17 [00134] 1 0.458 Y red 545 463 1 0.458 NA NA 18 [00135] 1.14 0.598 Y orange 405 496 407 1.17 0.628 NA NA 19 [00136] 0.97 0.428 Y orange 405 495 425 1 0.458 NA NA

TABLE-US-00003 TABLE 2 E.sub.1 .sup.1/2 (V) 1 2 E.sub.1 .sup.1/2 vs N reversi- max max Ref Structure (V) SHE bility color (nm) (nm) COMP 1 [00137] 0.62 0.078 Y green 442 645 COMP 2 [00138] 0.79 0.248 Y blue 399 608 COMP 3 [00139] 0.41 0.132 Y blue 400 620 E.sub.1.sup.red E1 peak E.sub.2.sup.red E2 peak cut peak potential peak potential (nm) potential (V) vs potential (V) vs Ref clear (V) SHE (V) SHE E.sup.red COMP 1 395 0.64 0.098 0.93 0.388 0.29 COMP 2 316 0.84 0.298 1.2 0.658 0.36 COMP 3 410 0.47 0.072 0.69 0.148 0.22