Process of producing polycarbonate by copolymerization of carbon dioxide and epoxide using the same as catalyst

Abstract

Provided are a complex prepared from ammonium salt-containing ligands and having such an equilibrium structural formula that the metal center takes a negative charge of 2 or higher, and a method for preparing polycarbonate via copolymerization of an epoxide compound and carbon dioxide using the complex as a catalyst. When the complex is used as a catalyst for copolymerizing an epoxide compound and carbon dioxide, it shows high activity and high selectivity and provides high-molecular weight polycarbonate, and thus easily applicable to commercial processes. In addition, after forming polycarbonate via carbon dioxide/epoxide copolymerization using the complex as a catalyst, the catalyst may be separately recovered from the copolymer.

Claims

1. A method for preparing polycarbonate, comprising carrying out copolymerization of an epoxide compound with carbon dioxide using a complex represented by Chemical Formula 6: ##STR00039## wherein A.sup.1 and A.sup.2 independently represent an oxygen or sulfur atom; Xb and Xc independently represents 2,4-dinitrophenolate or BF.sub.4.sup.−; R.sup.62 and R.sup.64 are independently selected from tert-butyl, methyl, ethyl, isopropyl and hydrogen, and R.sup.61 and R.sup.63 independently represent —[CH{(CH.sub.2).sub.3N.sup.+Bu.sub.3}.sub.2] or —[CMe{(CH.sub.2).sub.3N.sup.+Bu.sub.3}.sub.2]; b+c−1 represents 4; and A.sup.3 represents —CH═N-Q-N═CH— and Q represents trans-1,2-cyclohexylene or ethylene as a catalyst.

2. The method according to claim 1, wherein the epoxide compound is selected from the group consisting of (C2-C20) alkylene oxide substituted or unsubstituted by a halogen or alkoxy; (C4-C20) cycloalkylene oxide substituted or unsubstituted by a halogen or alkoxy; and (C8-C20) styrene oxide substituted or unsubstituted by a halogen, alkoxy, alkyl or aryl.

3. A method for preparing polycarbonate, comprising carrying out copolymerization of an epoxide compound with carbon dioxide using a complex represented by Chemical Formula 6: ##STR00040## wherein A.sup.1 and A.sup.2 independently represent an oxygen or sulfur atom; one of Xb and Xc represents BF.sub.4.sup.−, two of them represent 2,4-dinitrophenolate, and the remaining two are anions represented by Chemical Formula 10; R.sup.62 and R.sup.64 are independently selected from tert-butyl, methyl, ethyl, isopropyl and hydrogen, and R.sup.61 and R.sup.63 independently represent —[CH{(CH.sub.2).sub.3N.sup.+Bu.sub.3}.sub.2] or —[CMe{(CH.sub.2).sub.3N.sup.+Bu.sub.3}.sub.2]; b+c−1 represents 4; and A.sup.3 represents —CH═N-Q-N═CH— and Q represents trans-1,2-cyclohexylene or ethylene as a catalyst, [Chemical Formula 10] ##STR00041## wherein R represents methyl or H.

Description

DESCRIPTION OF DRAWINGS

(1) The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:

(2) FIG. 1 shows .sup.1H NMR spectra of compounds 7 and 8 in DMSO-d.sub.6 as a solvent, wherein the signals labeled with X correspond to DNP signals and the 2D spectrum in the box is .sup.1H-.sup.1H COSY NMR spectrum of compound 7 at 20° T.

(3) FIG. 2 shows .sup.13C NMR spectra of compounds 7 and 8 in DMSO-d.sub.6 as a solvent.

(4) FIG. 3 shows .sup.15N NMR spectra of compounds 7 and 8 in DMSO-d.sub.6 as a solvent.

(5) FIG. 4 shows .sup.1H NMR spectra of compounds 7 and 8 in THF-d.sub.8 and CD.sub.2Cl.sub.2 as a solvent.

(6) FIG. 5 shows IR spectra of compounds 7 and 8.

(7) FIG. 6 shows the most stable conformation of compound 7 obtained by DFT calculation, wherein only the oxygen atoms of DNP ligands coordinated to the metal are shown for the purpose of simplicity.

(8) FIG. 7 is a reaction scheme illustrating a change in the state of DNP at room temperature depending on the solvent, in the case of a compound with a different coordination system having no coordination with imine (X=DNP).

(9) FIG. 8 shows VT .sup.1H NMR spectrum of compound 7 in THF-d.sub.8.

(10) FIG. 9 is .sup.1H NMR spectrum illustrating the reaction between compound 10 or 8 and propylene oxide, wherein the signals marked with “*” correspond to new signals derived from the anion of Meisenheimer salt.

BEST MODE

(11) Hereinafter, the embodiments of the present invention will be described in detail with reference to examples. However, the following examples are for illustrative purposes only and not intended to limit the scope of this disclosure.

Example 1

Preparation of 3-methyl-5-[{BF4−Bu3N+(CH2)3}2CH}]-salicylaldehyde compound

(12) The title compound is prepared by hydrolyzing the ligand represented by Chemical Formula 19a. The compound represented by Chemical Formula 19a is obtained by the known method developed by the present inventors (Angew. Chem. Int. Ed., 2008, 47, 7306-7309).

(13) ##STR00029##

(14) The compound represented by Chemical Formula 19a (0.500 g, 0.279 mmol) was dissolved in methylene chloride (4 mL), and then aqueous HI solution (2N, 2.5 mL) was added thereto and the resultant mixture was agitated for 3 hours at 70° C. The aqueous layer was removed, the methylene chloride layer was washed with water and dried with anhydrous magnesium chloride, and the solvents were removed under reduced pressure. The resultant product was purified by silica gel column chromatography eluting with methylene chloride/ethanol (10:1) to obtain 0.462 g of 3-methyl-5-[{I-Bu.sub.3N+(CH.sub.2).sub.3}.sub.2CH}]-salicylaldehyde (yield 95%). The compound was dissolved in ethanol (6 mL), and AgBF.sub.4 (0.225 g, 1.16 mmol) was added thereto, and the resultant mixture was stirred for 1.5 hours at room temperature, followed by filteration. The solvents were removed under reduced pressure and the resultant product was purified by silica gel column chromatography eluting with methylene chloride/ethanol (10:1) to obtain 0.410 g of 3-methyl-5-[{BF.sub.4—Bu.sub.3N+(CH.sub.2).sub.3}.sub.2CH}]-salicylaldehyde compound (yield 100%).

(15) .sup.1H NMR (CDCl.sub.3): δ 11.19 (s, 1H, OH), 9.89 (s, 1H, CHO), 7.48 (s, 1H, m-H), 7.29 (s, 1H, m-H), 3.32-3.26 (m, 4H, —NCH.sub.2), 3.10-3.06 (m, 12H, —NCH.sub.2), 2.77 (septet, J=6.8 Hz, 1H, —CH—), 2.24 (s, 3H, —CH.sub.3), 1.76-1.64 (m, 8H, —CH.sub.2), 1.58-1.44 (m, 16H, —CH.sub.2), 1.34-1.29 (m, 8H, —CH.sub.2), 0.90 (t, J=7.6 Hz, 18H, CH.sub.3) ppm. .sup.13C {.sup.1H} NMR (CDCl.sub.3): δ 197.29, 158.40, 136.63, 133.48, 130.51, 127.12, 119.74, 58.23, 40.91, 32.51, 23.58, 19.48, 18.82, 15.10, 13.45 ppm.

Example 2

Preparation of 3-t-butyl-5-[{BF4−Bu3N+(CH2)3}2CH}]-salicylaldehyde compound

(16) The title compound is prepared from the compound represented by Chemical Formula 19b in the same manner as described in Example 1. The compound represented by Chemical Formula 19a is also obtained by the known method developed by the present inventors (Angew. Chem. Int. Ed., 2008, 47, 7306-7309).

(17) ##STR00030##

(18) .sup.1H NMR (CDCl.sub.3): δ 11.76 (s, 1H, OH), 9.92 (s, 1H, CHO), 7.53 (s, 1H, m-H), 7.35 (s, 1H, m-H), 3.36-3.22 (m, 16H, —NCH.sub.2), 2.82 (br, 1H, —CH—), 1.78-1.70 (m, 4H, —CH.sub.2), 1.66-1.46 (m, 16H, —CH.sub.2), 1.42 (s, 9H, —C(CH.sub.3).sub.3), 1.38-1.32 (m, 12H, butyl —CH.sub.2), 0.93 (t, J=7.6 Hz, 18H, CH.sub.3) ppm. .sup.13C {.sup.1H} NMR (CDCl.sub.3): δ 197.76, 159.67, 138.70, 133.50, 132.63, 131.10, 120.40, 58.55, 41.45, 34.99, 32.28, 29.31, 23.72, 19.59, 19.00, 13.54 ppm.

Example 3

Preparation of Complex 7

(19) Reaction Scheme 4 schematically illustrates one embodiment of the method for preparing the complex disclosed herein.

(20) ##STR00031##

(21) Ethylene diamine dihydrochloride (10 mg, 0.074 mmol), sodium t-butoxide (14 mg) and 3-methyl-5-[{BF.sub.4.sup.−Bu.sub.3N+(CH.sub.2).sub.3}.sub.2CH}]-salicylaldehyde compound (115 mg) obtained from Example 1 are weighed with vials in a dry box, and ethanol (2 mL) was added thereto, followed by stirring at room temperature for overnight. The reaction mixture was filtered and solvent were removed under reduced pressure. The resultant product was redissolved into methylene chloride and filtered once again. The solvents were removed under reduced pressure, and Co(OAc).sub.2 (13 mg, 0.074 mmol) and ethanol (2 mL) are added thereto. The reaction mixture was stirred for 3 hours at room temperature and then the solvents were removed under reduced pressure. The resultant compound was washed with diethyl ether (2 mL) twice to obtain a solid compound. The solid compound was dissolved into methylene chloride (2 mL) and 2,4-dinitrophenol (14 mg, 0.074 mmol) was added thereto, and the resultant mixture was stirred for 3 hours in the presence of oxygen. Then, sodium 2,4-dinitrophenolate (92 mg, 0.44 mmol) was added to the reaction mixture and the stirring continued for overnight at room temperature. The reaction mixture was filtered over a pad of Celite and the solvents were removed to obtain the product as a dark brown solid compound (149 mg, yield 100%).

(22) .sup.1H NMR (DMSO-d.sub.6, 40° C.): δ 8.84 (br, 2H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 8.09 (br, 2H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 8.04 (s, 1H, CH═N), 7.12 (s, 2H, m-H), 6.66 (br, 2H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 4.21 (br, 2H, ethylene-CH.sub.2), 3.35-2.90 (br, 16H, NCH.sub.2), 2.62 (s, 3H, CH.sub.3), 1.91 (s, 1H, CH), 1.68-1.42 (br, 20H, CH.sub.2), 1.19 (br, 12H, CH.sub.2), 0.83 (br, 18H, OH.sub.3) ppm. .sup.1H NMR (THF-d.sub.8, 20° C.): δ 8.59 (br, 1H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 8.10 (br, 1H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 7.93 (s, 1H, CH═N), 7.88 (br, 1H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 7.05 (s, 1H, m-H), 6.90 (s, 1H, m-H), 4.51 (s, 2H, ethylene-CH.sub.2), 3.20-2.90 (br, 16H, NCH.sub.2), 2.69 (s, 3H, CH.sub.3), 1.73 (s, 1H, CH), 1.68-1.38 (br, 20H, CH.sub.2), 1.21 (m, 12H, CH.sub.2), 0.84 (t, J=6.8 Hz, 18H, CH.sub.3) ppm. .sup.1H NMR (CD.sub.2Cl.sub.2, 20° C.): δ 8.43 (br, 1H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 8.15 (br, 1H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 7.92 (br, 1H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 7.79 (s, 1H, CH═N), 6.87 (s, 1H, m-H), 6.86 (s, 1H, m-H), 4.45 (s, 2H, ethylene-CH.sub.2), 3.26 (br, 2H, NCH.sub.2), 3.0-2.86 (br, 14H, NCH.sub.2), 2.65 (s, 3H, CH.sub.3), 2.49 (br, 1H, CH), 1.61-1.32 (br, 20H, CH.sub.2), 1.31-1.18 (m, 12H, CH.sub.2), 0.86 (t, J=6.8 Hz, 18H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (DMSO-d.sub.6, 40° C.): δ 170.33, 165.12, 160.61, 132.12 (br), 129.70, 128.97, 127.68 (br), 124.51 (br), 116.18 (br), 56.46, 40.85, 31.76, 21.92, 18.04, 16.16, 12.22 ppm. .sup.15N{.sup.1H} NMR (DMSO-d.sub.6, 20° C.): δ −156.32, −159.21 ppm. .sup.15N{.sup.1H} NMR (THF-d.sub.8, 20° C.): δ −154.19 ppm. .sup.19F{.sup.1H} NMR (DMSO-d.sub.6, 20° C.): δ −50.63, −50.69 ppm.

Example 4

Preparation of Complex 8

(23) Complex 8 is prepared from 3-t-butyl-5-[{BF.sub.4.sup.−Bu.sub.3N.sup.+(CH.sub.2).sub.3}.sub.2CH}]-salicylaldehyde obtained from Example 2 in the same manner as described in Example 3.

(24) .sup.1H NMR (DMSO-d.sub.6, 40° C.): δ 8.82 (br, 2H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 7.89 (br, 3H, (NO.sub.2).sub.2C.sub.6H.sub.3O, CH═N), 7.21 (s, 1H, m-H), 7.19 (s, 1H, m-H), 6.46 (br, 4H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 4.12 (s, 2H, ethylene-CH.sub.2), 3.25-2.96 (br, 16H, NCH.sub.2), 1.90 (s, 1H, CH), 1.71 (s, 9H, C(CH.sub.3).sub.3), 1.67-1.32 (br, 20H, CH.sub.2), 1.32-1.15 (m, 12H, CH.sub.2), 0.88 (t, J=7.2 Hz, 18H, CH.sub.3) ppm. .sup.1H NMR (THF-d.sub.8 20° C.): δ 7.78 (s, 1H, CH═N), 7.31 (s, 1H, m-H), 7.12 (s, 1H, m-H), 4.19 (br, 2H, ethylene-CH.sub.2), 3.43-2.95 (br, 16H, NCH.sub.2), 2.48 (br, 1H, CH), 1.81-1.52 (br, 20H, CH.sub.2), 1.50 (s, 9H, C(CH.sub.3).sub.3), 1.42-1.15 (br, 12H, CH.sub.2), 0.89 (t, J=6.8 Hz, 18H, CH.sub.3) ppm. .sup.1H NMR (CD.sub.2Cl.sub.2, 20° C.): δ 7.47 (s, 1H, CH═N), 7.10 (s, 1H, m-H), 7.07 (s, 1H, m-H), 4.24 (s, 2H, ethylene-CH.sub.2), 3.31 (br, 2H, NCH.sub.2), 3.09-2.95 (br, 14H, NCH.sub.2), 2.64 (br, 1H, CH), 1.68-1.50 (br, 20H, CH.sub.2), 1.49 (s, 9H, C(CH.sub.3).sub.3), 1.39-1.26 (m, 12H, CH.sub.2), 0.93 (t, J=6.8 Hz, 18H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (DMSO-d.sub.6, 40° C.): (166.57, 166.46, 161.55, 142.16, 129.99, 129.26, 128.39, 128.13, 127.63, 124.18, 118.34, 56.93, 41.64, 34.88, 32.27, 29.63, 22.37, 18.64, 18.51, 12.70 ppm. .sup.15N{.sup.1H} NMR (DMSO-d.sub.6): −163.43 ppm. .sup.15N{.sup.1H} NMR (THF-d.sub.8, 20° C.): δ −166.80 ppm. .sup.19F{.sup.1H} NMR (DMSO-d.sub.6, 20° C.): δ −50.65, −50.70 ppm.

Example 5

Preparation of Complex 9

(25) Complex 9 is prepared according to Reaction scheme 5.

(26) ##STR00032##

Preparation of Compound 17

(27) First, 1-chloro-4-iodobutane (1.00 g, 4.57 mmol) was dissolved into a mixture solvent of diethyl ether/pentane (2:3) to obtain a concentration of 0.10 M, the resultant mixture was cooled to −78° C. t-butyl lithium (3.690 g, 9.610 mmol, 1.7M solution in pentane) was added gradually to the cooled solution of 1-chloro-4-iodobutane and stirred for 2 hours. 1,5-dichloropentane-3-one (838 mg, 4.580 mmol) dissolved in diethyl ether (8 mL) was added gradually to the reaction mixture. The reaction mixture was stirred for additional 4 hours at −78° C., and then ice water (50 mL) was added to quench the reaction path, followed by extraction with diethyl ether. The organic layer was collected and dried over anhydrous magnesium sulfate and filtered, the solvents were removed under reduced pressure. The obtained crude product was purified by column chromatography using silica gel (hexane:ethyl acetate=5:1) to obtain 820 mg of compound 17 (yield 65%).

(28) .sup.1H NMR (CDCl.sub.3): δ 3.52 (t, J=6.4 Hz, 6H, CH.sub.2Cl), 1.80-1.73 (m, 6H, CH.sub.2), 1.56-1.52 (m, 4H, CH.sub.2), 1.42 (s, 4H, CH.sub.2) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ 73.58, 45.69, 44.95, 38.29, 36.48, 32.94, 26.96, 20.88 ppm.

Preparation of Compound 18

(29) Under nitrogen atmosphere, compound 17 (1.122 g, 4,070 mmol), o-cresol (3.521 g, 32.56 mmol), and aluminum trichloride (0.597 g, 4,477 mmol) were added to a round bottom flask and stirred for overnight. Diethyl ether (20 mL) and water (20 mL) were added thereto the reaction flask, and the aqueous phase was repeatedly extracted with diethyl ether (three times). The organic phases are combined and dried over anhydrous magnesium sulfate, filtered and removed the solvents under reduced pressure. The resultant oily product was purified by column chromatography using silica gel (hexane:ethyl acetate=10:1) to obtain 907 mg of compound 18 (yield 61%).

(30) IR (KBr): 3535 (OH) cm.sup.−1. .sup.1H NMR (CDCl.sub.3): δ 7.02 (d, J=2.0 Hz, 1H, m-H), 6.99 (dd, J=8.8 Hz, 2.0 Hz, 1H, m-H), 6.73 (d, J=8.0 Hz, 1H, o-H), 4.67 (s, 1H, OH), 3.53-3.46 (m, 6H, CH.sub.2Cl), 2.27 (s, 3H, CH.sub.3), 1.79-1.44 (m, 6H, CH.sub.2), 1.67-1.62 (m, 2H, CH.sub.2), 1.58-1.53 (m, 4H, CH.sub.2), 1.28-1.20 (br, 2H, CH.sub.2) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ 151.81, 137.96, 128.89, 124.87, 114.70, 60.83, 46.05, 45.04, 42.09, 36.69, 35.07, 27.26, 21.40, 21.02, 16.54, 14.49 ppm. HRMS (FAB): m/z calcd (M.sup.+C.sub.18H.sub.27Cl.sub.3O) 364.1131. found 365.1206.

Preparation of Compound 19

(31) Compound 18 (907 mg, 2.48 mmol), paraformaldehyde (298 mg, 9.920 mmol), magnesium dichloride (944 mg, 9.92 mmol) and triethylamine (1.051 g, 10.42 mmol) were introduced into a flask, and tetrahydrofuran (50 mL) was added as the solvent. The reaction mixture was refluxed for 5 hours under nitrogen atmosphere. The reaction mixture was cooled to room temperature, and methylene chloride (50 mL) and water (50 mL) were added thereto to extract the organic layer. The organic layer was collected and dried over anhydrous magnesium sulfate, filtered and removed the solvents. The resultant product was purified by column chromatography using silica gel (hexane:ethyl acetate=20:1) to obtain 540 mg of compound 19 (yield 58%).

(32) IR (KBr): 2947 (OH), 1650 (C═O) cm.sup.−1. .sup.1H NMR (CDCl.sub.3): δ 11.05 (s, 1H, OH), 9.78 (s, 1H, CH═O), 7.25 (s, 1H, m-H), 7.19 (s, 1H, m-H), 3.44-3.39 (m, 6H, CH.sub.2Cl), 2.19 (s, 3H, CH.sub.3), 1.74-1.43 (m, 12H, CH.sub.2), 1.20-1.11 (br, 2H, CH.sub.2) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ 196.79, 158.07, 136.98, 135.85, 128.95, 126.85, 119.52, 45.77, 44.88, 42.12, 36.50, 34.64, 33.09, 27.07, 20.85, 15.71 ppm. HRMS (FAB): m/z calcd (M.sup.+C.sub.19H.sub.27Cl.sub.3O) 393.1151. found 393.1155.

Preparation of Compound 20

(33) Compound 19 (520 mg, 1.304 mol) and sodium iodide (2.932 g, 19.56 mmol) were introduced into a flask, and acetonitrile (2 mL) was added as the solvent, followed by refluxing for 12 hours. Then, the solvent is removed under reduced pressure, methylene chloride (5 mL) and water (5 mL) are added thereto to extract the organic layer. The organic layer is dried over anhydrous magnesium sulfate and the solvent is removed under reduced pressure. The resultant product is purified through a column (hexane:ethyl acetate=20:1) to obtain 759 mg of compound 20 (yield 87%).

(34) IR (KBr): 2936 (OH), 1648 (C═O) cm.sup.−1. .sup.1H NMR (CDCl.sub.3): δ 11.06 (s, 1H, OH), 9.80 (s, 1H, CH═O), 7.25 (s, 1H, m-H), 7.17 (d, J=2.8 Hz, 1H, m-H), 3.21-3.14 (m, 6H, CH.sub.2Cl), 2.27 (s, 3H, CH.sub.3), 1.79-1.53 (m, 12H, CH.sub.2), 1.28-1.19 (br, 2H, CH.sub.2) ppm. .sup.13{.sup.1H} NMR (CDCl.sub.3): δ 196.81, 158.20, 137.00, 135.90, 128.90, 126.98, 119.54, 42.17, 38.45, 36.11, 33.93, 27.83, 24.50, 15.84, 7.96, 7.14 ppm.

Preparation of Compound 21

(35) Compound 20 (680 mg, 1.018 mmol) and cyclohexyl diamine (58 mg, 0.509 mmol) were dissolved in methylene chloride (5 mL) and the reaction mixture was stirred for 12 hours. The resultant product was purified by passing through a short pad of silica eluting with methylene chloride to obtain the product as a pure yellow solid (560 mg, yield 78%).

(36) IR (KBr): 2933 (OH), 1629 (C═N) cm.sup.−1. .sup.1H NMR (CDCl.sub.3): δ 13.45 (s, 2H, OH), 8.34 (s, 2H, CH═N), 7.05 (s, 2H, m-H), 6.941 (d, J=1.6 Hz, 2H, m-H), 3.39-3.36 (m, 2H, cyclohexyl-CH), 3.17-3.09 (m, 12H, CH.sub.2I), 2.26 (s, 6H, CH.sub.3), 1.96-1.89 (m, 4H, cyclohexyl-CH.sub.2), 0.96-1.43 (m, 32H, cyclohexyl-CH.sub.2 and CH.sub.2), 1.18-1.20 (br, 4H, CH.sub.2) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ164.97, 157.2, 135.58, 131.25, 127.12, 125.50, 117.65, 72.89, 42.00, 38.71, 36.14, 34.18, 33.73, 27.91, 24.57, 24.50, 16.32, 8.26, 7.18 ppm.

Preparation of Compound 22

(37) Compound 21 (364 mg, 0.257 mmol) was dissolved in acetonitrile (5 mL), and added tributylamine (291 mg, 1.57 mmol). The reaction mixture was reflux for 2 days under nitrogen atmosphere. The reaction mixture was cooled to room temperature, the solvents were removed under reduced pressure, and diethyl ether (10 mL) was added. The resultant slurry was stirred for 10 minutes to obtain the product in solid form. Diethyl ether was decanted and the above process was repeated twice. The yellow solid was collected by filtration followed by washing with diethyl ether. The residual solvents were completely by applying vacuum to obtain 579 mg of compound 22 (yield 89%).

(38) IR (KBr): 2959 (OH), 1627 (C═N) cm.sup.−1. .sup.1H NMR (CDCl.sub.3): δ. 13.46 (s, 2H, OH), 8.58 (s, 2H, CH═N), 7.18 (s, 2H, m-H), 7.07 (s, 2H, m-H), 3.42 (br, 2H, cyclohexyl-CH), 3.32 (br, 16H, NCH.sub.2), 3.16 (br, 32H, NCH.sub.2), 2.10 (s, 6H, CH.sub.3), 1.74-1.20 (br, 108H, cyclohexyl-CH.sub.2, CH.sub.2), 0.86 (t, 18H, CH.sub.3), 0.75 (t, 36H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ164.78, 157.27, 134.04, 130.82, 127.22, 125.15, 117.46, 71.01, 9.96, 59.63, 59.00, 58.86, 53.52, 43.03, 34.89, 33.90, 33.68, 24.16, 24.05, 23.07, 22.78, 20.69, 19.68, 19.53, 17.64, 15.79, 13.58 ppm.

Preparation of Compound 23

(39) Compound 22 (455 mg, 0.180 mmol) and silver tetrafluoro borate (211 mg, 1.08 mmol) were introduced into a flask, and methylene chloride (12 mL) is added as a solvent. The flask was wrapped with aluminum foil and the reaction mixture was stirred at room temperature for 1 day. The reaction mixture was filtered over a pad of celite to remove solid, and the remaining solution was removed under reduced pressure. The product was purified by column chromatography using silica gel (methylene chloride:ethanol=5:1) to obtain 322 mg of yellow compound 23 (yield 78%).

(40) IR (KBr): 2961 (OH), 1628 (C═N) cm.sup.−1. .sup.1H NMR (CDCl.sub.3): δ. 13.64 (s, 2H, OH), 8.52 (s, 2H, CH═N), 7.27 (s, 2H, m-H), 7.16 (s, 2H, m-H), 3.44 (br, 2H, cyclohexyl-CH), 3.30-3.10 (br, 48H, NCH.sub.2), 2.24 (s, 6H, CH.sub.3), 1.95-1.29 (br, 108H, cyclohexyl-CH.sub.2, CH.sub.2), 0.99 (t, 18H, CH.sub.3), 0.90 (t, 36H, CH.sub.3) ppm.

Preparation of Complex 9

(41) Compound 23 (59 mg, 0.026 mmol) and Co(OAc).sub.2 (4.6 mg, 0.026 mmol) were introduced into a vial in a glove box, ethanol (1 mL) was added and the reaction mixture was stirred for 12 hours. The solvent was removed under reduced pressure and the resultant product was washed twice with diethyl ether to obtain a red solid. 2,4-dinitrophenol (5.0 mg, 0.026 mmol) was added to and the reaction mixture and stirred for 3 hours in the presence of oxygen atmosphere. sodium 2,4-dinitrophenolate (27 mg, 0.13 mmol) was added to the reaction flask and stirred for further 12 hours. The resultant solution was filtered over a pad of celite, removed the solvents under reduced pressure to obtain 73 mg of a dark red solid.

(42) IR (KBr): 2961 (OH), 1607 (C═N) cm.sup.−1. .sup.1H NMR (DMSO-d.sub.6, 38° C.): δ 8.68 (br, 4H, (NO.sub.2).sub.2C.sub.6H.sub.3O), δ. 8.05 (br, 4H, (NO.sub.2).sub.2C6H.sub.3O), 7.85 (br, 2H, CH═N), 7.30 (br, 4H, m-H), 6.76 (br, 4H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 3.58 (br, 2H, cyclohexyl-CH), 3.09 (br, 48H, NCH.sub.2), 2.63 (s, 6H, CH.sub.3), 1.53-1.06 (br, 108H, cyclohexyl-CH.sub.2, CH.sub.2), 0.93-0.85 (m, 54H, CH.sub.3) ppm.

Example 6

Preparation of Complex 10

(43) Complex 10 is prepared according to Reaction Scheme 6.

(44) ##STR00033## ##STR00034##

Preparation of Compound 24

(45) First, 1,7-dichloroheptan-4-one (17.40 g, 95.04 mmol) was dissolved into diethyl ether (285 mL) under nitrogen atmosphere. The reaction mixture was cooled to −78° C., MeLi (1.5 M solution in diethyl ether 80.97 g, 142.56 mmol) was added drop wise using a syringe under nitrogen atmosphere. The reaction mixture was stirred for 2 hours at −78° C. water (170 mL) was added at −78° C. to quench the reaction. The product was extracted using diethyl ether. The aqueous layer was repeatedly extracted with diethyl ether (2 times). Collected the organic phases and dried over anhydrous magnesium sulfate, followed by filtration and the solvents were removed under reduced pressure to obtain 17.99 g of compound 24 (yield 95%). The resultant product may be used directly for the subsequent reaction without further purification.

(46) .sup.1H NMR (CDCl.sub.3): δ. 3.59 (t, J=6.4 Hz, 4H, CH.sub.2Cl), 1.90-1.86 (m, 4H, CH.sub.2), 1.64-1.60 (m, 4H, CH.sub.2), 1.23 (s, 3H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDC.sub.3): δ. 72.32, 45.88, 39.51, 27.60, 27.23 ppm.

Preparation of Compound 25

(47) Under nitrogen atmosphere, o-cresol (78.17 g, 722.82 mmol), compound 24 (17.99 g, 90.35 mmol) and AlCl.sub.3 (13.25 g, 99.39 mmol) were mixed in a round bottom flask and stirred overnight. Diethyl ether (500 mL) and water (300 mL) were added to quench the reaction. The organic layer was collected and the aqueous layer was further extracted three times with diethyl ether (300 mL) and collected the organic layer. The organic layer was dried over anhydrous magnesium sulfate, followed by filtration, and then the solvent were removed by a rotary evaporator under reduced pressure. The excess o-cresol was removed by vacuum distillation (2 mm Hg) at 85° C. The obtained product can be used for subsequent reaction without further purification. In this manner, 25.40 g of compound 25 was obtained (yield 97%).

(48) .sup.1H NMR (CDCl.sub.3): δ. 7.01 (d, J=2.0 Hz, 1H, m-H), 6.97 (dd, J=8.0 Hz, 2.0 Hz, 1H, m-H), 6.72 (d, J=8.0 Hz, 1H, o-H), 4.85 (s, 1H, OH), 3.45 (t, J=6.4 Hz, 4H, CH.sub.2Cl), 2.27 (s, 3H, CH.sub.3), 1.86-1.44 (m, 8H, CH.sub.2), 1.30 (s, 3H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ. 151.79, 138.67, 129.06, 125.02, 123.45, 114.85, 46.20, 41.12, 39.95, 28.09, 24.22, 16.58 ppm.

Preparation of Compound 26

(49) Compound 25 (25.40 g, 87.83 mmol) was dissolved in tetrahydrofuran (650 mL) under nitrogen atmosphere. Paraformaldehyde (10.55 g, 351.32 mmol), magnesium chloride (33.52 g, 351.32 mmol) and triethylamine (37.31 g, 368.89 mmol) were introduced, into a flask under nitrogen atmosphere, and a refluxed for 5 hours under nitrogen atmosphere. The solvent was removed by a rotary evaporator under reduced pressure and methylene chloride (500 mL) and water (300 mL) were added. The resultant mixture was filtered over a pad of Celite to obtain a methylene chloride layer. The aqueous layer was further extracted three times with methylene chloride (300 mL) and combined organic layers, dried over anhydrous magnesium sulfate and filtered, the solvents were removed by a rotary evaporator under reduced pressure to obtain an oily compound. The remaining trace amount of triethylamine is removed by a vacuum pump. The resultant compound has high purity as determined by NMR analysis and can be used for the subsequent reaction without further purification. In this manner, 26.75 g of compound 26 was obtained (yield 96%).

(50) .sup.1H NMR (CDCl.sub.3): δ. 11.14 (s, 1H, OH), 9.87 (s, 1H, CH═O), 7.33 (d, J=2.4 Hz, 1H, m-H), 7.26 (d, J=2.4 Hz, 1H, m-H), 3.47 (t, J=6.4 Hz, 4H, CH.sub.2Cl), 2.30 (s, 3H, CH.sub.3), 1.90-1.40 (m, 8H, CH.sub.2), 1.35 (s, 3H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ. 196.87, 158.22, 137.56, 136.11, 128.91, 119.69, 45.88, 40.67, 39.98, 27.96, 24.06, 15.81 ppm.

Preparation of Compound 27

(51) Compound 26 (26.75 g, 84.32 mmol) was dissolved in acetonitrile (107 mL). Sodium iodide (126.39 g, 843.18 mmol) was added and the resulting mixture was refluxed for overnight. After cooling the reaction mixture to room temperature, water (300 mL) was added. The resultant solution was extracted three times with diethyl ether (300 mL) to collect the organic layer. The organic layer was dried over anhydrous magnesium sulfate, followed by filtration; the solvents were removed by a rotary evaporator under reduced pressure. The resultant product was purified through silica gel column chromatography eluting with hexane-toluene (5:1) as eluent to obtain the compound 27 (22.17 g, yield 83%).

(52) .sup.1H NMR (CDCl.sub.3): δ. 11.14 (s, 1H, OH), 9.87 (s, 1H, CH═O), 7.33 (d, J=2.4 Hz, 1H, m-H), 7.25 (d, J=2.4 Hz, 1H, m-H), 3.14-3.09 (m, 4H, CH.sub.2I), 2.30 (s, 3H, CH.sub.3), 1.87-1.43 (m, 8H, CH.sub.2), 1.34 (s, 3H, CH.sub.3) ppm. .sup.13C{H} NMR (CDCl.sub.3): δ. 196.85, 158.20, 137.50, 136.09, 128.85, 126.93, 119.62, 44.28, 39.95, 28.66, 24.16, 15.81, 7.99 ppm.

Preparation of Compound 28

(53) Compound 27 (8.56 g, 17.01 mmol) was dissolved in methylene chloride (97 mL) under nitrogen atmosphere. (±)-trans-1,2-diaminocyclohexane (0.97 g, 8.50 mmol) was added and stirred for overnight. Solvents were removed under reduced pressure to obtain the pure compound (9.00 g, yield 98%).

(54) .sup.1H NMR (CDCl.sub.3): δ. 13.48 (s, 1H, OH), 8.31 (s, 1H, CH═N), 7.04 (d, J=1.6 Hz, 1H, m-H), 6.91 (d, J=1.6 Hz, 1H, m-H), 3.38-3.35 (m, 1H, cyclohexyl-CH), 3.08-3.03 (m, 4H, CH.sub.2I), 2.25 (s, 3H, CH.sub.3), 1.96-1.89 (m, 2H, cyclohexyl-CH.sub.2), 1.96-1.43 (m, 10H, cyclohexyl-CH.sub.2 and CH.sub.2), 1.26 (s, 3H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ. 165.01, 157.31, 136.12, 131.35, 126.93, 125.54, 117.67, 72.94, 44.47, 39.79, 33.73, 28.72, 24.57, 24.32, 16.28, 8.38, 8.26 ppm.

Preparation of Compound 29

(55) Compound 28 (0.855 g, 0.79 mmol) was dissolved in acetonitrile (8.5 mL) under nitrogen atmosphere, tributyl amine (1.17 g, 6.32 mmol) was added and the resulting solution was refluxed for 48 hours. Solvents were removed by a rotary evaporator under reduced pressure. Diethyl ether (20 mL) was added to the obtained slurry and titurated for 15 minutes to precipitate the product as solid. The ether layer was decanted and the above process was repeated twice to obtain beige solid compound. The solid compound was added gradually to solution of AgBF.sub.4 (0.642 g, 3.30 mmol) in ethanol (40 mL) with stirring. The reaction mixture was agitated for 24 hours under light-shielded atmosphere, and the resultant AgI was removed by filteration over a pad of celite. The solvents were removed under vacuum. Then, the resultant compound was dissolved in methylene chloride (6 mL), and further filtered through a Celite pad to remove floating materials. The resultant product was purified by column chromatography using silica, eluting with methylene chloride-ethanol (5:1) as eluent to obtain the purified compound (1.23 g, yield 90%).

(56) .sup.1H NMR (CDCl.sub.3): δ. 13.55 (s, 1H, OH), 8.42 (s, 1H, CH═N), 7.12 (s, 1H, m-H), 7.08 (s, 1H, m-H), 3.38 (br, 1H, cyclohexyl-CH), 3.06 (br, 16H, NCH.sub.2), 2.20 (s, 3H, CH.sub.3), 1.88-1.84 (br, 2H, cyclohexyl-CH.sub.2), 1.68-1.26 (br, 36H), 0.87-0.86 (br, 18H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ. 165.23, 157.79, 135.21, 131.17, 127.18, 125.76, 117.91, 72.05, 59.16, 58.63, 40.16, 38.10, 37.71, 26.45, 24.91, 23.90, 20.31, 19.80, 17.30, 16.01, 13.97, 13.80, 13.79 ppm.

Preparation of Complex 10

(57) Compound 29 (100 mg, 0.06 mmol) and Co(OAc).sub.2 (10.7 mg, 0.06 mmol) were introduced into a flask and ethanol (3 mL) was added as the solvent. The reaction mixture was stirred at room temperature for 3 hours and removed the solvents under reduced pressure. The obtained product was triturated 2 times with diethyl ether to obtain the red solid compound. The residual solvents were removed completely by applying reduced pressure. Methylene chloride (3 mL) was added to dissolve the compound. Then, 2,4-dinitrophenol (11.1 mg, 0.06 mmol) was introduced and the reaction mixture was stirred for 3 hours under oxygen atmosphere. Under oxygen atmosphere, sodium-2,4-dinitrophenolate (74.5 mg, 0.30 mmol) was introduced and the mixture was stirred for overnight. The resultant solution was filtered over a pad of celite and the solvents were removed under reduced pressure to obtain the complex 10 (137 mg, yield 100%).

(58) .sup.1H NMR (DMSO-d.sub.6, 38° C.): δ. 8.65 (br, 2H, (NO.sub.2).sub.2C.sub.6H.sub.3O), δ. 7.88 (br, 3H, (NO.sub.2).sub.2C.sub.6H.sub.3O, CH═N), 7.31 (br, 2H, m-H), 6.39 (br, 2H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 3.38 (br, 1H, cyclohexyl-CH), 3.08 (br, 16H, NCH.sub.2), 2.64 (s, 3H, CH.sub.3), 2.06-1.85 (br, 2H, cyclohexyl-CH.sub.2), 1.50-1.15 (br, 36H), 0.86 (br, 18H, CH.sub.3) ppm.

Example 7

Preparation of Complex 11

(59) 3-methyl-5-[{BF.sub.4.sup.−Bu.sub.3N.sup.+(CH.sub.2).sub.3}.sub.2CH.sub.3C}]-salicylaldehyde compound (493 mg, 0.623 mmol) and 2,3-diamino-2,3-dimethylbutane (36 mg, 0.311 mmol) were introduced into a flask. Ethanol (4 mL) was added as the solvent, molecular sieves (180 mg) were introduced and the resultant mixture was subjected to reflux for 12 hours under nitrogen atmosphere. The mixture was filtered through a Celite pad to remove the molecular sieves and removed the solvents under reduced pressure to obtain the product as yellow solid. Co(OAc).sub.2 (55 mg, 0.31 mmol) was added to the flask and ethanol (10 mL) as the solvent. The resulting mixture was stirred for 5 hours at room temperature. Solvents were removed under reduced pressure, and the resulting compound was triturated twice with diethyl ether to obtain the red color compound. 2,4-dinitrophenol (57 mg, 0.311 mmol) was added and the mixture was dissolved in methylene chloride (10 mL) and stirred for 12 hours in the presence of oxygen. Sodium-2,4-dinitrophenolate (320 mg, 1.56 mmol) was added and the resulting reaction mixture was stirred for further 12 hours. The solution was filtered over a pad of celite and the solvents were removed under reduced pressure to obtain 736 mg of a dark red solid product.

(60) .sup.1H NMR (DMSO-d.sub.6, 38° C.): δ 8.62 (br, 4H, (NO.sub.2).sub.2O.sub.6H.sub.3O), 7.87 (br, 4H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 7.72 (br, 2H, CH═N), 7.50 (br, 2H, m-H), 7.35 (br, 2H, m-H), 6.47 (br, 4H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 3.11 (br, 32H, NCH.sub.2), 2.70 (s, 6H, CH.sub.3), 1.66-1.22 (br, 82H), 0.88 (br, 36H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (DMSO-d.sub.6): δ 164.67, 159.42, 132.30, 129.71, 128.86 (br), 128.46 (br), 127.42 (br), 124.05 (br), 118.84, 73.92, 57.74, 57.19, 25.94, 23.33, 22.61, 21.05, 18.73, 16.68, 16.43, 12.93 ppm.

Example 8

Preparation of Complex 12

(61) Salen ligand (500 mg, 0.301 mmol) obtained from 3-methyl-5-[{BF.sub.4.sup.−Bu.sub.3N.sup.+(CH.sub.2).sub.3}.sub.2CH}]-salicylaldehyde compound and Co(OAc).sub.2 (53 mg, 0.30 mmol) were introduced into a flask, and added ethanol (15 mL) as solvent, the resulting solution was stirred for 3 hours under nitrogen atmosphere. The solvent was removed under reduced pressure, and the resultant compound was triturated twice with diethyl ether to obtain red color compound. The compound was dissolved in methylene chloride (10 mL). Then, HBF.sub.4 (49 mg, 0.30 mmol) was added to the resultant solution in the presence of oxygen, followed by stirring for additional 3 hours. After that, the solvents were removed under reduced pressure to obtain 520 mg of a pure compound. Complex 12 was prepared according to the known method developed by the present inventors (Angew. Chem. Int. Ed., 2008, 47, 7306-7309).

Example 9

Preparation of Complex 13

(62) Complex 13 was obtained with a Salen ligand obtained from 3-t-butyl-5-[{BF.sub.4.sup.−Bu.sub.3N.sup.+(CH.sub.2).sub.3}.sub.2CH}]-salicylaldehyde compound in the same manner as described in Example 8.

(63) .sup.1H NMR (DMSO-d.sub.6, 40° C.): δ 7.68 (s, 1H, CH═N), 7.36 (s, 1H, m-H), 7.23 (s, 1H, m-H), 3.61 (br, 1H, NCH), 3.31-2.91 (br, 16H, NCH.sub.2), 2.04 (br, 1H, cyclohexyl-CH.sub.2), 1.89 (br, 1H, cyclohexyl-CH.sub.2), 1.74 (s, 9H, C(CH.sub.3).sub.3), 1.68-1.35 (br, 20H, CH.sub.2), 1.32-1.18 (br, 12H, CH.sub.2), 0.91 (t, J=7.2 Hz, 18H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (DMSO-d.sub.6): δ 161.66, 160.42, 140.90, 129.71, 128.38, 127.31, 117.38, 67.40, 55.85, 33.89, 31.11, 28.70, 27.70 (br), 22.58, 21.29, 19.47, 17.45, 15.21, 11.69 ppm.

Example 10

Preparation of Complex 14

(64) Compound 10 was dissolved in propylene oxide, and the solution was allowed to stand for 1 hour and then removed the solvents under vacuum to obtain the complex 14.

(65) .sup.1H NMR (DMSO-d.sub.6): δ 8.59 (s, 1H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 8.42 (s, 1H, spiro-Meisenheimer anion), 7.74 (s, 1H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 7.39-6.98 (m, 3H, m-H, CH═N), 6.81 (s, 1H, spiro-Meisenheimer anion), 6.29 (s, (NO.sub.2).sub.2C.sub.6H.sub.3O), 5.35 (s, 1H, spiro-Meisenheimer anion), 4.43-4.29 (m, 1H, spiro-Meisenheimer anion), 4.21-3.99 (m, 2H, spiro-Meisenheimer anion), 3.21 (br, 1H, NCH), 3.09 (br, 16H, NCH.sub.2), 2.93 (m, 3H, spiro-Meisenheimer anion), 2.62 (s, 3H, CH.sub.3), 1.98 (br, 1H, cyclohexyl-CH.sub.2), 1.62-1.39 (br, 20H, CH.sub.2), 1.39-1.15 (br, 15H, CH.sub.2, CH.sub.3), 0.91 (br, 18H, CH.sub.3) ppm.

Example 11

Preparation of Complex 35a

(66) ##STR00035##

Preparation of 1,7-dichloro-4-methylheptan-4-ol

(67) Under nitrogen atmosphere, 1,7-dichloro-4-methylheptan-4-one (17.40 g, 95.04 mmol) was dissolved in diethyl ether (285 mL). The reaction mixture was cooled to −78° C. and MeLi (1.5 M solution in diethyl ether, 80.97 g, 142.56 mmol) was added dropwise using a syringe under nitrogen atmosphere. The resulting mixture was stirred for 2 hours at −78° C. Water (170 mL) was added at −78° C. to quench the reaction path. The reaction mixture was extracted three times with diethyl ether (300 mL) and collected the organic phases. Combined the organic layers and dried over anhydrous magnesium sulfate, followed by filtration, and the solvents were removed by a rotary evaporator under reduced pressure to obtain 17.99 g (yield 95%) of the title compound, which may be used for the subsequent reaction without further purification.

(68) .sup.1H NMR (CDCl.sub.3): δ. 3.59 (t, J=6.4 Hz, 4H, CH.sub.2Cl), 1.90-1.86 (m, 4H, CH.sub.2), 1.64-1.60 (m, 4H, CH.sub.2), 1.23 (s, 3H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ. 72.32, 45.88, 39.51, 27.60, 27.23.

Preparation of Complex 35a

(69) Under nitrogen atmosphere, o-cresol (78.17 g, 722.82 mmol), 1,7-dichloro-4-methylheptane-4-ol (17.99 g, 90.35 mmol) and AlCl.sub.3 (13.25 g, 99.39 mmol) were mixed in a round bottom flask and stirred overnight. Next, diethyl ether (500 mL) and water (300 mL) are introduced thereto to quench the reaction. The organic layers were collected, and the aqueous layer was further extracted three times with diethyl ether (300 mL). Combined the organic phases and dried over anhydrous magnesium sulfate, followed by filtration, and the solvents were removed by a rotary evaporator under reduced pressure. The excess o-cresol was removed by vacuum distillation (2 mmHg) at an oil bath temperature of 85° C. The compound remaining in the flask has a purity sufficient to be used for the subsequent reaction without further purification. In this manner, 25.40 g of complex 35a is obtained (yield 97%).

(70) .sup.1H NMR (CDCl.sub.3): δ. 7.01 (d, J=2.0 Hz, 1H, m-H), 6.97 (dd, J=8.0 Hz, 2.0 Hz, 1H, m-H), 6.72 (d, J=8.0 Hz, 1H, o-H), 4.85 (s, 1H, OH), 3.45 (t, J=6.4 Hz, 4H, CH.sub.2Cl), 2.27 (s, 3H, CH.sub.3), 1.86-1.44 (m, 8H, CH.sub.2), 1.30 (s, 3H, CH.sub.3) ppm. .sup.13C{.sup.1H}NMR (CDCl.sub.3): δ. 151.79, 138.67, 129.06, 125.02, 123.45, 114.85, 46.20, 41.12, 39.95, 28.09, 24.22, 16.58

Example 12

Preparation of Complex 39a

(71) ##STR00036##

Preparation of Complex 36a

(72) Complex 35a (25.40 g, 87.83 mmol) was dissolved in tetrahydrofuran (650 mL) under nitrogen atmosphere. Paraformaldehyde (10.55 g, 351.32 mmol), magnesium chloride (33.52 g, 351.32 mmol) and triethylamine (37.31 g, 368.89 mmol) were introduced, into a flask under nitrogen atmosphere, and a refluxed for 5 hours under nitrogen atmosphere. The solvent was removed by a rotary evaporator under reduced pressure and methylene chloride (500 mL) and water (300 mL) were added. The resultant mixture was filtered over a pad of Celite to obtain a methylene chloride layer. The aqueous layer was further extracted three times with methylene chloride (300 mL) and combined organic layers, dried over anhydrous magnesium sulfate and filtered, the solvents were removed by a rotary evaporator under reduced pressure to obtain an oily compound. The remaining trace amount of triethylamine is removed by a vacuum pump. The resultant compound has high purity as determined by NMR analysis and can be used for the subsequent reaction without further purification. In this manner 26.75 g of complex 36a was obtained (yield 96%).

(73) .sup.1H NMR (CDCl.sub.3): δ. 11.14 (s, 1H, OH), 9.87 (s, 1H, CH═O), 7.33 (d, J=2.4 Hz, 1H, m-H), 7.26 (d, J=2.4 Hz, 1H, m-H), 3.47 (t, J=6.4 Hz, 4H, CH.sub.2Cl), 2.30 (s, 3H, CH.sub.3), 1.90-1.40 (m, 8H, CH.sub.2), 1.35 (s, 3H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDC.sub.3): δ. 196.87, 158.22, 137.56, 136.11, 128.91, 119.69, 45.88, 40.67, 39.98, 27.96, 24.06, 15.81.

Preparation of Complex 37a

(74) Complex 36a (26.75 g, 84.32 mmol) was dissolved in acetonitrile (107 mL). Sodium iodide (126.39 g, 843.18 mmol) was added to the solution and the resulting solution was refluxed for overnight. After cooling the mixture to room temperature, water (300 mL) was added to quench the reaction path. The resultant solution was extracted three times with diethyl ether (300 mL) and collected the organic layers. The collected organic layer was dried over anhydrous magnesium sulfate, followed by filtration, and the solvents were removed by a rotary evaporator under reduced pressure. The resultant compound was purified by column chromatography using silica gel, eluting with hexane-toluene (5:1) as eluent to obtain pure complex 37a (22.17 g, yield 83%).

(75) .sup.1H NMR (CDCl.sub.3): δ. 11.14 (s, 1H, OH), 9.87 (s, 1H, CH═O), 7.33 (d, J=2.4 Hz, 1H, m-H), 7.25 (d, J=2.4 Hz, 1H, m-H), 3.14-3.09 (m, 4H, CH.sub.2I), 2.30 (s, 3H, CH.sub.3), 1.87-1.43 (m, 8H, CH.sub.2), 1.34 (s, 3H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ. 196.85, 158.20, 137.50, 136.09, 128.85, 126.93, 119.62, 44.28, 39.95, 28.66, 24.16, 15.81, 7.99.

Preparation of Complex 38a

(76) Complex 37a (8.56 g, 17.01 mmol) was dissolved in methylene chloride (97 mL) under nitrogen atmosphere. (±)-trans-1,2-diaminocyclohexane (0.97 g, 8.50 mmol) was added and stirred for overnight. The solvents were removed under reduced pressure to obtain pure complex 38a (9.00 g, yield 98%).

(77) .sup.1H NMR (CDCl.sub.3): δ. 13.48 (s, 1H, OH), 8.31 (s, 1H, CH═N), 7.04 (d, J=1.6 Hz, 1H, m-H), 6.91 (d, J=1.6 Hz, 1H, m-H), 3.38-3.35 (m, 1H, cyclohexyl-CH), 3.08-3.03 (m, 4H, CH.sub.2I), 2.25 (s, 3H, CH.sub.3), 1.96-1.89 (m, 2H, cyclohexyl-CH.sub.2), 1.96-1.43 (m, 10H, cyclohexyl-CH.sub.2 and CH.sub.2), 1.26 (s, 3H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ. 165.01, 157.31, 136.12, 131.35, 126.93, 125.54, 117.67, 72.94, 44.47, 39.79, 33.73, 28.72, 24.57, 24.32, 16.28, 8.38, 8.26.

Preparation of Complex 39a

(78) Complex 38a (0.855 g, 0.79 mmol) is dissolved into acetonitrile (8.5 mL) under nitrogen atmosphere, tributyl amine (1.17 g, 6.32 mmol) was added and the resulting solution was refluxed for 48 hours. Solvents were removed by a rotary evaporator under reduced pressure. Diethyl ether (20 mL) was added to the obtained slurry and titurated for 15 minutes to precipitate the product as solid. The ether layer was decanted and the above process was repeated twice to obtain beige solid compound. The solid compound was added gradually to solution of AgBF.sub.4 (0.642 g, 3.30 mmol) in ethanol (40 mL) with stirring. The reaction mixture was agitated for 24 hours under light-shielded atmosphere, and the resultant AgI was removed by filtration over a pad of celite. The solvents were removed under vacuum. Then, the resultant compound was dissolved in methylene chloride (6 mL), and further filtered through a Celite pad to remove floating materials. The resultant product was purified by column chromatography using silica, eluting with methylene chloride-ethanol (5:1) as eluent to obtain the 39a (1.23 g, yield 90%).

(79) .sup.1H NMR (CDCl.sub.3): δ. 13.55 (s, 1H, OH), 8.42 (s, 1H, CH═N), 7.12 (s, 1H, m-H), 7.08 (s, 1H, m-H), 3.38 (br, 1H, cyclohexyl-CH), 3.06 (br, 16H, NCH.sub.2), 2.20 (s, 3H, CH.sub.3), 1.88-1.84 (br, 2H, cyclohexyl-CH.sub.2), 1.68-1.26 (br, 36H), 0.87-0.86 (br, 18H, CH.sub.3) ppm. .sup.13C{.sup.1H} NMR (CDCl.sub.3): δ. 165.23, 157.79, 135.21, 131.17, 127.18, 125.76, 117.91, 72.05, 59.16, 58.63, 40.16, 38.10, 37.71, 26.45, 24.91, 23.90, 20.31, 19.80, 17.30, 16.01, 13.97, 13.80, 13.79

Example 13

Preparation of Complex 40a

(80) ##STR00037##

Preparation of Complex 40a

(81) Complex 39a (100 mg, 0.06 mmol) and Co(OAc).sub.2 (10.7 mg, 0.06 mmol) were introduced into a flask and ethanol (3 mL) was added as the solvent. The reaction mixture was stirred at room temperature for 3 hours and removed the solvents under reduced pressure. The obtained product was triturated 2 times with diethyl ether to obtain the red solid compound. The residual solvents were removed completely by applying reduced pressure. Methylene chloride (3 mL) was added to dissolve the compound. Then, 2,4-dinitrophenol (11.1 mg, 0.06 mmol) was introduced and the reaction mixture was stirred for 3 hours under oxygen atmosphere. Under oxygen atmosphere, sodium-2,4-dinitrophenolate (74.5 mg, 0.30 mmol) was introduced and the mixture was stirred for overnight. The resultant solution was filtered over a pad of celite and the solvents were removed under reduced pressure to obtain the complex 40a (138 mg, yield 100%).

(82) .sup.1H NMR (DMSO-d.sub.6, 38° C.): δ. 8.65 (br, 2H, (NO.sub.2).sub.2C.sub.6H.sub.3O), δ. 7.88 (br, 3H, (NO.sub.2).sub.2C.sub.6H.sub.3O, CH═N), 7.31 (br, 2H, m-H), 6.39 (br, 2H, (NO.sub.2).sub.2C.sub.6H.sub.3O), 3.38 (br, 1H, cyclohexyl-CH), 3.08 (br, 16H, NCH.sub.2), 2.64 (s, 3H, CH.sub.3), 2.06-1.85 (br, 2H, cyclohexyl-CH.sub.2), 1.50-1.15 (br, 36H), 0.86 (br, 18H, CH.sub.3) ppm.

Example 14

Structural Analysis of Complexes

(83) Complexes 7 and 8 obtained from Examples 3 and 4 are subjected to intensive structural analysis.

(84) (1).sup.1H, .sup.13C and .sup.15N NMR spectra and IR spectrum

(85) FIGS. 1, 2, 3, 4 and 5 show .sup.1H NMR spectrum, .sup.13C NMR spectrum and .sup.15N NMR spectrum of compounds 7 and 8 in DMSO-d.sub.6 as a solvent, and .sup.1H NMR spectra of compounds 7 and 8 in THF-d.sub.8 and CD.sub.2Cl.sub.2 as solvents. It can be seen that the two compounds show clearly different behaviors. In the case of complex 8 prepared from a ligand wherein R is t-butyl, sharp signals appear in both .sup.1H NMR spectrum and .sup.13C NMR spectrum. This is a typical behavior of tetradentate Salen-Co (III) compound. In the .sup.15N NMR spectrum, only one signal appears at −163.43 ppm regardless of temperature.

(86) In the .sup.1H NMR spectrum and .sup.13C NMR spectrum of complex 7 (Example 3) prepared from a ligand wherein R is methyl, a very complex and broad signal appears at room temperature, a simple and broad signal is obtained at 40° C., and a sharp signal is obtained at 80° C. The ratio of [DNP]/[Salen-unit]obtained from integration of the .sup.1H NMR spectrum is near 4.0 rather than 5.0 observed in the case of complex 8. As determined by .sup.15N NMR, two signals appear at −156.32 and −159.21 ppm under room temperature, a broad signal including two fused signals appears at 40° C., and only one sharp signal appears at 80° C.

(87) Complexes 7 and 8 show significantly different behaviors as determined by .sup.1H NMR spectrometry in THF-d.sub.8 or CD.sub.2Cl.sub.2 (FIG. 4). In the .sup.1H NMR spectrum of complex 8, a set of Salen-unit signals appears and a very broad DNP signal appears. Especially, some signals appear at an abnormal range, −2 to 0 ppm. This suggests that some paramagnetic compounds are present. In the case of .sup.1H NMR spectrum of complex 7, only one set of Salen-unit signals appears, which has a significantly different chemical shift from complex 8. Broad DNP signals are observed at 7.88, 8.01 and 8.59 ppm. However, the ratio of [DNP]/[Salen-unit]integration is about 2.0, and only two DNP signals are observed among the four DNP signals observed in DMSO-d.sub.6 with the remaining two non-observed. As determined in CD.sub.2Cl.sub.2, .sup.1H NMR spectrometric behaviors of complexes 7 and 8 are similar to those in THF-d.sub.8.

(88) In the .sup.15N NMR spectrum in THF-d.sub.8, a sharp signal appears at −166.80 ppm (complex 8) or −154.32 ppm (complex 7). It is not reasonable to regard such a difference in chemical shift values of 12.5 ppm as a difference caused merely by the effect of substituents. It is reported that chemical shift values in the .sup.15N NMR spectrum of imine compounds (—N═C—C.sub.4H.sub.4—X) and hydrazone compounds (N—N═C—C.sub.4H.sub.4—X) follow the Hammett type equation with a gradient of about 10. Considering a difference caused by the methyl and t-butyl substituents, the two substituents contribute a difference in chemical shift values of 1 ppm or less (Neuvonen, K.; Fülöp, F.; Neuvonen, H.; Koch, A.; Kleinpeter, E.; Pihlaja, K. J. Org. Chem. 2003, 68, 2151). In addition, in the case of dipyrrolmethene ligand and zinc (II) compounds obtained therefrom, substitution of hydrogen with ethyl provides a difference in chemical shift values of 2 ppm in .sup.15N NMR spectrometry (Wood, T. E.; Berno, B.; Beshara, C. S.; Thompson, Alison, J. Org. Chem. 2006, 71, 2964). In fact, when viewed from the state of ligands used for preparing complexes 7 and 8, chemical shift difference is as low as 2.86 ppm. Therefore, it can be thought that the value of chemical shift of 12.5 ppm as observed herein results from different structures of the two complexes, i.e. complexes 7 and 8. When observing .sup.15N NMR spectrum in THF-d.sub.8 while varying temperature, complex 7 shows a relatively broadened signal as the temperature decreases, resulting in a full width at half maximum (FWHM) of 10 ppm at −75° C. On the other hand, complex 8 shows a relatively sharp signal at −75° C. as determined by a FWHM of 1.5 ppm. The above results suggest that complex 8 has a general structure of rigid Salen-Co (III) compounds to which all of the four ligands of Salen are coordinated, while complex 7 has a more flexible structure different therefrom.

(89) As shown in FIG. 5, the two complexes show clearly different signals in a range of 1200-1400 cm.sup.−1 corresponding to the symmetric vibration of —NO.sub.2 in IR spectra.

(90) (2) Suggestion of Structure of Complexes

(91) It can be said that complex 8 has a structure of a general Salen ligand-containing cobalt complex in which all of the four ligands of Salen are coordinated to cobalt, when observed by the .sup.1H, .sup.13C, and .sup.15N NMR spectra. After carrying out ICP-AES, elemental analysis and .sup.19F NMR spectrometry, it is found that one equivalent of NaBF.sub.4 is inserted into the complex. In the .sup.1H NMR spectrum, a broad DNP signal is observed, which suggests that the DNP ligand undergoes continuous conversion/reversion between the coordinated state and the de-coordinated state. As a part of the conversion/reversion, a square-pyramidal cobalt compound may be present transiently and the square-pyrimidal compound is known to be a paramagnetic compound [(a) Konig, E.; Kremer, S.; Schnakig, R.; Kanellakopulos, B. Chem. Phys. 1978, 34, 79. (b) Kemper, S.; Hrobàrik, P.; Kaupp, M.; Schlörer, N. E. J. Am. Chem. Soc. 2009, 131, 4172.]. Therefore, an abnormal signal is always observed at −2 to 0 ppm in the .sup.1H NMR spectrum of complex 8.

(92) When complex 7 has the above-mentioned non-imine coordinated structure, the analytic data may be understood. In addition, the structure is demonstrated through the following DFT calculation and electrochemical experiments. The structure is characterized in that four DNP ions, which are conjugate anions of quaternary ammonium salt, are coordinated instead of imine. The last operation of the catalyst preparation includes reaction with 5 equivalents of NaDNP suspended in CH.sub.2Cl.sub.2 to perform a change of [BF.sub.4].sup.− into DNP anion. [DNP]/[Salen-unit]integration ratio is 4.0 and this is not significantly changed even when using a more excessive amount of NaDNP (10 equivalents) or when increasing the reaction time. In other words, one among the four BF.sub.4 remains unsubstituted. Since BF.sub.4 signals are observed in .sup.19F NMR but Na.sup.+ ion is not observed from ICP-AES analysis unlike complex 8, it can be seen that BF.sub.4 anion is present as a conjugate anion of quaternary ammonium salt. Even when preparing a catalyst with ligands having more quaternary ammonium salt units like complex 9, only the compound having four DNP ligands are observed even in the presence of a significantly excessive amount of NaDNP and even after a longer time. It is thought that an octahedral coordination compound having two Salen-phenoxy ligands and four DNP ligands is obtained in methylene chloride as a solvent, and formation of the octahedral compound causes the anion exchange. Cobalt (III) metal is classified into hard acid, and the hard acid prefers DNP to imine-base, resulting in the compound with such a different structure. In the case of complex 8, steric hindrance of t-butyl hinders formation of such a compound. The octahedral cobalt (III) compound in which cobalt has a charge of −3 is previously known [(a) Yagi, T.; Hanai, H.; Komorita, T.; Suzuki T.; Kaizaki S. J. Chem. Soc., Dalton Trans. 2002, 1126. (b) Fujita, M.; Gillards, R. D. Polyhedron 1988, 7, 2731.]

(93) Complexes 5, 9 and 10 provide .sup.1H and .sup.13C NMR spectrum and IR spectrum behaviors similar to complex 7, and thus may be regarded as a complex with a different coordination system having no imine coordination. Particularly, complex 5 has been regarded as a general Salen-compound structure having imine coordination like complex 8 in the previously known publication of the present inventors (Angew. Chem. Int. Ed., 2008, 47, 7306-7309) and patent applications [Korean Patent Application No. 10-2008-0015454 (2008 Feb. 20, titled with “METHOD FOR RECOVERING CATALYST FROM COPOLYMER PREPARATION PROCESS”, Bun Yeoul Lee, Sujith S, Eun Kyung Noh, Jae Ki Min, “A PROCESS PRODUCING POLYCARBONATE AND A COORDINATION COMPLEXES USED THEREFOR” PCT/KR2008/002453 (2008 Apr. 30); Sujith S, Jae Ki Min, Jong Eon Seong, Sung Jea Na, and Bun Yeoul Lee* “A HIGHLY ACTIVE AND RECYCLABLE CATALYTIC SYSTEM FOR CO.sub.2/(PROPYLENE OXIDE)”]. However, it is found herein that complex 5 has such a different structure.

(94) Complexes 6 and 11 provide .sup.1H and .sup.13C NMR spectrum and IR spectrum behaviors similar to complex 8, and thus may be regarded as a general Salen-compound structure having imine coordination.

(95) (3) DFT calculation

(96) DFT calculation is carried out to determine the structures and energy levels of complex 7 with a different coordination structure having no imine coordination, and another complex that are an isomer of complex 7 and have a general imine coordination structure, wherein two DNP ligands are coordinated at the axial site and the remaining two are present in a free state. FIG. 6 shows the most stable conformation of complex 7 obtained from the calculation. As can be seen from FIG. 6, complex 7 with a different structure having no imine coordination as disclosed herein has a more stable energy level than the general imine-coordinated structure by 132 kcal/mol. Such a difference in energy levels is significant.

(97) (4) Movability of DNP Ligand

(98) When observed from .sup.1H NMR in methylene chloride used in the last anion exchange reaction during the preparation of a catalyst, complexes 7, 9 and 10 show DNP signals at 8.4, 8.1 and 7.9 ppm with a [DNP]/[Salen-unit]integration ratio of 2.0 (FIG. 4). In other words, only two DNP ligands are observed among the four DNP ligands with the remaining two non-observed. This is because two DNP ligands undergo continuous conversion/reversion between the coordinated state and the non-coordinated state at a level of NMR time.

(99) On the other hand, in the case of complex 5, four DNP signals are observed at the same range. The DNP signals observed herein has a chemical shift greatly different from the chemical shift of [Bu.sub.4N].sup.+[DNP].sup.−. Thus, it is though that the observed signals result from DNP coordinated in the complex. In other words, in the case of complexes 7, 9 and 10, two DNP ligands are coordinated and the remaining two undergo continuous conversion/reversion between the coordinated state and de-coordinated state in methylene chloride solvent at room temperature. In the case of complex 5, four DNP ligands are coordinated. FIG. 7 is a reaction scheme illustrating a change in the state of DNP at room temperature depending on the solvent, in the case of a compound with a different coordination system having no coordination with imine. As demonstrate by FIG. 7, the above statement that the complex obtained from the last anion exchange reaction has an octahedral coordination structure having two Salen-phenoxy ligands and four DNP ligands conforms to the structure adopted from the DFT calculation.

(100) In addition, as observed from .sup.1H NMR spectrum of complex 7 measured in THF-d.sub.8 at room temperature, signals corresponding to the two coordinated DNP ligands are observed at 8.6, 8.1 and 7.9 ppm (FIG. 4). When the temperature is reduced to 0° C., the signals become sharper and a signal coupling behavior is observed. The coordinated DNP signals may be more clearly understood by determining .sup.1H-.sup.1H COSY NMR spectrum (FIG. 8). When the temperature is further reduced to −25° C., a new DNP signal is observed (marked with ‘*’ in FIG. 8). The new signal has a similar chemical shift to [Bu.sub.4N].sup.+DNP.sup.−. Thus, the new signal may be regarded as DNP remaining in the de-coordinated state for a long time. At 70° C., four DNP ligands are observed as one set of broad signals at 9.3, 9.0 and 7.8 ppm. This is similar to the chemical shift of the coordinated DNP signal, and it is thought that all of the four DNP ligands remain in the coordinated state for a long time. In other words, as the temperature increases, DNP ligands may be more adjacent to the cobalt center. The de-coordinated DNP ligands are surrounded with solvent molecules, resulting in a decrease in entropy. Such de-coordination accompanied with a decrease in entropy is preferred at low temperature. Thus, de-coordinated signals are observed at reduced temperature, while a shift into the coordinated state is observed at high temperature. Similarly, a transition from a contact ion pair to a solvent separated ion pair at reduced temperature is well known [(a) Streitwieser Jr., A.; Chang, C. J.; Hollyhead, W. B.; Murdoch, J. R. J. Am. Chem. Soc. 1972, 94, 5288. (b) Hogen-Esch, T. E.; Smid, J. J. Am. Chem. Soc. 1966, 88, 307. (c) Lü, J.-M.; Rosokha, S. V.; Lindeman, S. V.; Neretin, I. S.; Kochi, J. K. J. Am. Chem. Soc. 2005, 127, 1797]. FIG. 8 shows VT .sup.1H NMR spectrum of compound 7 in THF-d.sub.8.

(101) Salen Complex 8 coordinated with imine shows highly different .sup.1H NMR spectrum in THF-d.sub.8, as compared to complex 7. This demonstrates that complexes 7 and 8 have different structures. When reducing the temperature to 0° C., all DNP signals become broadened so that any signals may not be observed. At −25° C., a relatively sharp DNP signal set is observed at 8.1, 7.6 and 6.8 ppm with a [DNP]/[Salen-unit]integration ratio of 2.0. In addition, a significantly broad set of signals is observed at 8.9, 8.0 and 6.8 ppm, and these chemical shift values are similar to the chemical shift values (8.7, 8.0 and 6.8 ppm) of DNP remaining in the de-coordinated state for a long time as observed in complex 7. At −50° C., the two sets of signals become sharper so that two sets of DNP signals may be seen clearly. The DNP signals observed at 8.1, 7.6 and 6.8 ppm may correspond to two DNP ligands coordinated at the axial site of the conventional Salen coordination complex. Another set of signals observed at 8.9, 8.0 and 6.8 ppm may correspond to the de-coordinated state.

(102) The state of DNP in THF at room temperature depending on the structure of ligand is demonstrated via .sup.1H NMR. In the case of complex 7, a set of signals of two coordinated DNP ligands is observed and the remaining two DNP ligands are not observed. This suggests that the two DNP ligands that are not observed herein undergo continuous conversion/reversion between the coordinated state and the de-coordinated state. On the other hand, in the cases of complexes 5, 9 and 10, two sets of signals, i.e., one set of two coordinated DNP signals and another set of signals of two DNP ligands remaining mainly in the de-coordinated state are observed. The signals of two DNP ligands remaining mainly in the de-coordinated state as observed in complexes 9 and 10 are broader than the corresponding signals in complex 5. This suggests that the two DNP ligands in complexes 9 and 10 remain in the de-coordinated state for a shorter time as compared to complex 5. As a result, the degree of retention (binding affinity to cobalt) of the two DNP ligands remaining mainly in the de-coordinated state is in order of 7>9 and 10>5.

(103) As determined from .sup.1H NMR spectrum of complexes 5, 7, 9 and 10 in DMSO-d.sub.6 at 40° C., four DNP ligands are observed as a set of broad signals (FIG. 1). The chemical shift values of the signals (8.6, 7.8 and 6.4 ppm) are similar to the chemical shift values of [Bu.sub.4N].sup.+DNP.sup.− (8.58, 7.80 and 6.35 ppm). Therefore, it can be said that the four DNP ligands remain mainly in the de-coordinated state at 40° C. However, such broad signals also suggest that the ligands undergo continuous conversion/reversion between the coordinated state and the de-coordinated state. At room temperature, another set of DNP signals are observed at 8.5, 8.1 and 7.8 ppm along with a set of signals of DNP ligands remaining mainly in the de-coordinated state with an integration ratio of 1:3. The less observed DNP signals have similar chemical shift values as compared to the chemical shift values of the coordinated DNP ligands observed in THF and methylene chloride. Thus, the signals may correspond to coordinated DNP ligands. In other words, in DMSO at room temperature, one DMP remains mainly in the coordinated state and the other three DMP ligands remain in the de-coordinated state. It is thought that DMSO is coordinated at the vacant site generated by de-coordination of DNP. DMSO is coordinated well to hard acid such as cobalt (III) metal.

(104) (5) Complicated NMR Spectrometric Analysis Observed in DMSO-d.sub.6

(105) The complicated .sup.1H, .sup.13C and .sup.15N NMR spectra of complex 7 observed in DMSO-d.sub.6 may be understood through the above-described non-imine coordinated structure and the state of DNP. In the structure and state of complex 7 in DMSO at room temperature as shown in FIG. 7, two phenoxy ligands contained in one Salen-unit are subjected to different situations. One phenoxy ligand is at trans-position to DMSO, and the other is at trans-position to DNP. Therefore, two signals are observed in .sup.15N NMR spectrum (FIG. 3), and a part of aromatic signals is divided at a ratio of 1:1 in .sup.1H and .sup.13C NMR (FIGS. 1 and 2). Especially, NCH.sub.2CH.sub.2N signal is divided into three signals at 4.3, 4.15 and 4.1 ppm with a ratio of 1:1:2. After the analysis through .sup.1H-.sup.1H COSY NMR spectrometry, it can be seen that three signals are derived from one NCH.sub.2CH.sub.2N-unit (FIG. 1). In the structure obtained by the DFT calculation, complex 7 shows a conformation of ═NCH.sub.2CH.sub.2N=unit and is similar to the structure as illustrated in FIG. 6. In the above structure, complex 7 may not be converted into a structural isomer of the cobalt octahedral structure. Thus, the structure having three DMSO coordinations and one DNP coordination is chiral. Due to such chirality, two hydrogen atoms of N—CH.sub.2 show NMR shift values at different positions. In the case of a complex with a chiral center, such as complex 5 or 10, .sup.1H and .sup.13C NMR spectra are more complicated. As the temperature increases to 40° C., two coordinated DNP signals disappear and one broad signal appears. In this case, the asymmetric coordination environment is broken and a simple Salen-ligand signal appears. Since the coordination environment around cobalt is symmetric in THF and CH.sub.2Cl.sub.2 at room temperature as shown in FIG. 7, a sharp Salen-ligand signal appears in .sup.1H, .sup.13C and .sup.15N NMR.

(106) (6) Cyclic Voltammetry (CV) Test

(107) CV test also indirectly demonstrates that complexes 5 and 6 have different structures. If complexes 5 and 6 have the same structure, complex 5 having a methyl substituent is expected to cause reduction more easily. This is because methyl has lower electron donating property than t-butyl, and thus the cobalt center has less abundant electrons so that the electrons go into the cobalt center more easily. However, the opposite results are observed. Complex 5 with a methyl substituent causes reduction at a more negative potential than complex 6. It is observed that complexes 5 and 6 have a E.sub.1/2 value of Co(III/II) of −0.076V and −0.013V, respectively, versus SCE. The difference, 63 mV, in reduction potentials between the two complexes is significant. A reduction potential difference of 59 mV from the Nernst equation [E=E°−(0.0592)log {[Ox]/[Red]}] means a difference in [Co(II)]/[Co(III)] ratios of 10 times at the same potential.

(108) On the other hand, it is expected that complexes 12 and 13 having no DNP ligands have the same general imine-coordinated structure regardless of methyl or t-butyl substitution in a non-coordinatable solvent such as methylene chloride. After carrying out CV study with complexes 12 and 13 in methylene chloride, the two complexes show the same reduction potential (0.63 V vs. SCE). In other words, there is no difference in reduction potentials between methyl substitution and t-butyl substitution under the same structure. Thus, the above difference in reduction potentials suggests that the two complexes have different coordination systems. When the solvent is changed from CH.sub.2Cl.sub.2 to DMSO, the reduction potential difference appears again. The reduction potentials of complexes 12 and 13 observed in DMSO (−0.074 and −0.011 V vs. SCE) are similar to the reduction potentials of complexes 5 and 6 observed in DMSO (−0.076 and −0.013 V vs. SCE). Since DMSO is coordinated well to cobalt (III) metal, in DMSO as a solvent, complex 12 is converted into a complex with a different coordination system, such as complex 5 having no imine coordination, while four DMSO ligands are coordinated to complex 12 having a methyl substituent.

(109) (7) Initiation Reaction

(110) Complex 10 reacts with propylene oxide. FIG. 9 is .sup.1H NMR spectrum illustrating the reaction between complex 10 or 8 and propylene oxide. The signal marked with ‘*’ is a newly generated signal that corresponds to the anion of Meisenheimer salt shown in complex 14. The oxygen atom of alkoxide obtained by the attack to propylene oxide coordinated with DNP further attacks ipso-position of the benzene ring, so that the anion of Meisenheimer salt is formed. Complicated aromatic signals of Salen are observed at 7.0-7.4 ppm. However, this is not caused by the breakage of the Salen-unit. When an excessive amount of acetic acid is added to the compound prepared after the reaction with propylene oxide, simple three Salen aromatic signals are observed. This suggests that the Salen-unit is not broken. The anion of Meisenheimer salt is stopped at a [Meisenheimer anion]/[DNP] integration ratio of 1:1. During the first one hour, DNP is converted rapidly into the anion of Meisenheimer salt so that the [Meisenheimer anion]/[DNP] integration ratio reaches 1:1. However, the conversion does not proceed any longer, and thus the integration ratio is unchanged even after 2 hours. The anion of Meisenheimer salt is a previously known compound [(a) Fendler, E. J.; Fendler, J. H.; Byrne, W. E.; Griff, C. E. J. Org. Chem. 1968, 33, 4141. (b) Bernasconi, C. F.; Cross, H. S. J. Org. Chem. 1974, 39, 1054)]. Conversion of DNP into the anion of Meisenheimer salt is significantly lowered in the presence of a certain amount of water. When 5 equivalents of water are present per equivalent of cobalt, the conversion rate is not significantly changed. However, introduction of 50 equivalents of water causes a rapid drop in the conversion rate, so that the [Meisenheimer anion]/[DNP] integration ratio becomes 0.47 after 1 hour, becomes 0.53 after 2 hours, and remains at 0.63 even after 4 hours while not providing complex 14 (FIG. 8).

(111) The reactivity of the general imine-coordinated complex 8 with propylene oxide is different from that of the non-imine coordinated complex 10. Although the same anion of Meisenheimer salt is observed, the [Meisenheimer anion]/[DNP] integration ratio is not stopped at 1.0 but gradually increases over time (0.96 after 1 hour; 1.4 after 2 hours; 1.8 after 7 hours; and 2.0 after 20 hours). Further, unlike the behavior of complex 10, complex 8 shows a relatively large amount of broad signals between −1 ppm and 0.5 ppm. This suggests that reduction into a paramagnetic cobalt (II) compound occurs. The broad signal gradually increases over time. The cobalt (II) compound has no catalytic activity.

Example 15

Preparation of Carbon Dioxide/Propylene Oxide Copolymer

(112) (a) Copolymerization Using Complexes of Examples 3-10 as Catalyst

(113) To a 50 mL bomb reactor, any one complex obtained from Examples 3-10 (used in an amount calculated according to a ratio of monomer/catalyst of 7.58) and propylene oxide (10.0 g, 172 mmol) are introduced in a dry box and the reactor is assembled. As soon as the reactor is removed from the dry box, carbon dioxide is introduced under a pressure of 18 bar, the reactor is introduced into an oil bath controlled previously to a temperature of 80° C. and agitation is initiated. The time at which carbon dioxide pressure starts to be decreased is measured and recorded. After that, the reaction is carried out for 1 hour, and then carbon dioxide gas is depressurized to terminate the reaction. To the resultant viscous solution, monomers (10 g) are further introduced to reduce the viscosity. Then, the resultant solution is passed through a silica gel column [400 mg, Merck, 0.040-0.063 mm particle diameter (230-400 mesh)] to obtain a colorless solution. The monomers are removed by depressurization under reduced pressure to obtain a white solid. The weight of the resultant polymer is measured to calculate turnover number (TON). The polymer is subjected to .sup.1H NMR spectrometry to calculate selectivity. The molecular weight of the resultant polymer is measured by GPC with calibration using polystyrene standards.

(114) (b) Copolymerization Using Complex of Example 13 as Catalyst

(115) To a 50 mL bomb reactor, complex 40a (6.85 mg, 0.0030 mmol, monomer/catalyst ratio=50,000) obtained from Example 13 and propylene oxide (9.00 g, 155 mmol) are introduced and the reactor is assembled. The reactor is introduced into an oil bath controlled previously to a temperature of 80° C. and is agitated for about 15 minutes so that the reactor temperature is in equilibrium with the bath temperature. Next, carbon dioxide is added under 20 bars. After 30 minutes, it is observed that carbon dioxide is depressurized while the reaction proceeds. Carbon dioxide is further injected continuously for 1 hour under 20 bars. To the resultant viscous solution, monomers (10 g) are further introduced to reduce the viscosity. Then, the resultant solution is passed through a silica gel column [400 mg, Merck, 0.040-0.063 mm particle diameter (230-400 mesh)] to obtain a colorless solution. The monomers are removed by depressurization under reduced pressure to obtain 2.15 g of a white solid. The catalytic activity of the complex used in this Example corresponds to a TON of 6100 and a turnover frequency (TOF) of 9200 h.sup.−1. The resultant polymer has a molecular weight (Mn) of 89000 and a polydispersity (Mw/Mn) of 1.21 as measured by GPC. The polymer formation selectivity is 96% as determined by .sup.1H NMR.

Example 16

Recovery of Copolymer and Catalyst

(116) In the cases of complexes 5, 7 and 10, the following process is used to recover catalysts. The colored portion containing a cobalt catalyst component at the top of the silica column in Example 12 is collected, and dispersed into methanol solution saturated with NaBF.sub.4 to obtain a red colored solution. The red solution is filtered, washed twice with methanol solution saturated with NaBF.sub.4 until the silica becomes colorless, the resultant solution is collected, and the solvent is removed by depressurization under reduced pressure. To the resultant solid, methylene chloride is added. In this manner, the brown colored cobalt compound is dissolved into methylene chloride, while the unsoluble white NaBF.sub.4 solid may be separated. To the methylene chloride solution, 2 equivalents of solid 2,4-dinitrophenol and 4 equivalents of sodium 2,4-dinitrophenolate are introduced per mole of the catalyst, followed by agitation overnight. The resultant mixture is filtered to remove methylene chloride solution and to obtain brown colored powder. After .sup.1H NMR analysis, the resultant compound is shown to be the same as the catalyst compound and to have similar activity in the copolymerization.

(117) Table 1 shows the polymerization reactivity of each catalyst.

(118) TABLE-US-00002 TABLE 1 Polymerization reactivity of each catalyst.sup.a Induction M.sub.n.sup.d No. Catalyst Time (min) TOF.sup.b Selectivity.sup.c (10.sup.−3) M.sub.w/M.sub.n  1 5  60.sup.e 13,000 92 210 1.26  2 6  0 1,300 84  38 2.34  3 7 120.sup.e 8,300 97 113 1.23  4 8  0 5,000 85 120 1.41  5 9 0  6 10 260.sup.e 11,000 96 140 1.17  7 11 0  8 14  30 13,000 99 170 1.21  9 15  0 15,000 99 270 1.26 10.sup.f 15  0 16,000 99 300 1.31 .sup.aPolymerization condition: PO (10 g, 170 mmol), [PO]/[Cat] = 100,000, CO.sub.2 (2.0-1.7 MPa), temperature 70-75° C., reaction time 60 minutes. .sup.bcalculated based on the weight of the polymer containing cyclic carbonate. .sup.ccalculated by .sup.1H NMR. .sup.dmeasured by GPC using polystyrene standards. .sup.einduction time of 1-10 hours depending on batch. .sup.fpolymerization using 220 g of PO.

(119) As can be seen from Table 1, the general compounds having imine coordination, i.e. complexes 6, 8 and 11 has little or no polymerization activity. On the other hand, the complexes with a different structure having no imine coordination according to the present invention have high polymerization activity. However, complex 9 with a different structure having no imine coordination but containing six ammonium units has no activity.

(120) Complexes 5, 7 and 10 have higher activity in order of 5>10>7, which is the converse of order of Co-binding affinity of weak bound DNP undergoing continuous conversion/reversion between the Co-coordinated state and the de-coordinated state.

(121) Complex 10 is used to perform many experiments. Under a high-temperature high-humidity condition in the summer season, a great change is observed in induction time (1-12 hours). After the induction time, polymerization rate are observed to be nearly constant (TOF, 9,000-11,000 h.sup.−1). In the summer season, the amount of water infiltrating into the dry box for a polymerization reactor is not negligible. In this case, the polymerization system absorbs water and the induction time varies with the amount of water. In fact, under a dry low-temperature condition in the winter season, induction time decreases to 1 hour. In this case, when an additional amount of water is added thereto (50 equivalents vs. cobalt), induction time increases to 3 hours (entry 10). Introduction of a significant amount of water (250 equivalents) does not allow polymerization.

(122) When a certain amount of water is present, the rate of polymerization initiation caused by an attack of DNP to propylene oxide is decreased significantly, as determined by NMR (FIG. 9). When using compound 15 obtained from the reaction with propylene oxide as a catalyst, it is possible to solve the problem of such a great change in induction time depending on the amount of water (entry 13). When using compound 15 as a catalyst, water sensitivity decreases to allow polymerization even under a [propylene oxide]/[catalyst] ratio of 150000:1, resulting in further improvement in TON (entry 14). Under such a condition, complex 10 has no polymerization activity even when using thoroughly purified propylene oxide. Compound 15 is obtained by dissolving a high concentration of complex 10 into propylene oxide and by performing a reaction for 1 hour. In this case, it is possible to neglect the ratio of [water remaining in propylene oxide]/[compound 10].

(123) The present application contains subject matter related to Korean Patent Application Nos. 10-2008-0074435, 10-2008-0126170, 10-2009-0054481 and 10-2009-0054569 filed in the Korean Intellectual Property Office on Jul. 30, 2008, Dec. 11, 2008, Jun. 18, 2009, and Jun. 18, 2009, the entire contents of which are incorporated herein by reference.

(124) While the present invention has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.