HETEROGENEOUS CATALYSTS AND USES THEREOF
20200122133 ยท 2020-04-23
Inventors
Cpc classification
B01J31/2409
PERFORMING OPERATIONS; TRANSPORTING
B01J2231/32
PERFORMING OPERATIONS; TRANSPORTING
C07C5/2581
CHEMISTRY; METALLURGY
B01J2231/766
PERFORMING OPERATIONS; TRANSPORTING
B01J2540/22
PERFORMING OPERATIONS; TRANSPORTING
B01J31/24
PERFORMING OPERATIONS; TRANSPORTING
International classification
B01J31/24
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Catalytic processes employing rhodium complexes are disclosed, wherein the catalytic processes involve an initial step of activation of a CH bond present within a hydrocarbon substrate. In contrast to prior art techniques, the catalytic processes of the invention can be conducted at low temperatures, and the catalytic compounds are themselves highly recyclable. Also disclosed are the rhodium complexes themselves and processes of making them.
Claims
1. A catalytic process comprising the step of: a) activating one or more CH bonds present within a C.sub.4-C.sub.10 hydrocarbon by contacting the C.sub.4-C.sub.10 hydrocarbon with a compound having a structure according to formula (I) shown below: ##STR00059## wherein Bd is a bidentate ligand bonded to Rh via two heteroatoms independently selected from P, N and S, wherein the two heteroatoms are independently optionally substituted with one or more substituents selected from iso-propyl, tert-butyl, sec-butyl, n-pentyl, iso-pentyl, neo-pentyl, tert-pentyl, sec-pentyl, 3-pentyl, iso-propoxy, tert-butoxy, sec-butoxy, n-pentoxy, iso-pentoxy, neo-pentoxy, tert-pentoxy, sec-pentoxy, 3-pentoxy, 6-8 membered carbocyclyl, 6-8 membered heterocyclyl, aryl or adamantyl, any of which may be optionally substituted with one or more substituents selected from halo, oxo, hydroxyl, (1-4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl, (1-4C)alkoxy, (1-4C)haloalkyl and N(R.sub.x)(R.sub.y), wherein R.sub.x and R.sub.y are each independently selected from hydrogen and (1-4C)alkyl; each X is independently a ligand that is weakly coordinated to Rh via one or more bond; n is 1, 2 or 3; Q is selected from B, Al, In and Ga; and each Ar is independently i. a phenyl group substituted with one or more substituents selected from halo, (1-3C)alkyl and (1-3C)haloalkyl, or ii. a (1-3C)alkoxy group substituted with one or more substituents selected from halo, (1-3C)alkyl and (1-3C)haloalkyl.
2. The catalytic process of claim 1, wherein each X is independently a ligand that is weakly coordinated to Rh via one or more bond, wherein the total energy of coordination of Rh to each X is <130 KJ mol.sup.1.
3-5. (canceled)
6. The catalytic process of claim 1, wherein Bd is a bis-phosphine bidentate ligand.
7. The catalytic process of claim 6, wherein the bis-phosphine bidentate ligand has a structure according to formula (II) shown below: ##STR00060## wherein R.sub.a, R.sub.a, R.sub.E, and R.sub.b are each independently iso-propyl, tert-butyl, 6-8 membered carbocyclyl, aryl or adamantyl, any of which may be optionally substituted with one or more substituents selected from halo, hydroxyl, (1-4C)alkyl and (1-4C)alkoxy; and W is a (1-5C)alkylene linking group optionally substituted with one or more groups R.sub.c, wherein each R.sub.c is independently (1-4C)alkyl or (1-4C)alkoxy, and/or two groups R.sub.c may be linked, such that when taken with the atoms to which they are attached, they form a phenyl group optionally substituted with one or more substituents selected from halo, (1-4C)alkyl and (1-4C)alkoxy.
8. (canceled)
9. The catalytic process of claim 7, wherein R.sub.a, R.sub.a, R.sub.b and R.sub.b are cyclohexyl.
10-13. (canceled)
14. The catalytic process of claim 6 wherein the two P atoms are linked by a linking group selected from (1-5C)alkylene, (2-5C)alkenylene and (2-5C)alkynylene, any of which may be optionally substituted with one or more substituents selected from halo, oxo, hydroxyl, (1-4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl and (1-4C)alkoxy.
15. (canceled)
16. The catalytic process of claim 14, wherein the two P atoms are linked by a methylene, ethylene, propylene, butylene or pentylene linking group.
17-18. (canceled)
19. The catalytic process of claim 1, wherein each X is hydrogen, an alkane, an alkene or dinitrogen.
20-24. (canceled)
25. The catalytic process of claim 1, wherein n is 1 and X is norbornane or n is 2 and each X is ethene.
26. The catalytic process of any preceding claim claim 1, wherein Q is B, Al or In.
27. (canceled)
28. The catalytic process of claim 1, wherein each Ar is either i) a phenyl group substituted at the 3-, 4- and/or 5-position with one or more substituents selected from halo (1-3C)alkyl and (1-3C)haloalkyl, or ii) a (1-3C)alkoxy group substituted with one or more substituents selected from halo (1-3C)alkyl and (1-3C)haloalkyl.
29-35. (canceled)
36. The catalytic process of claim 1, wherein [QAr.sub.4] has any of the following structures: ##STR00061## wherein R.sub.p is fluoro, chloro or trifluromethyl.
37. The catalytic process of claim 1, wherein the compound according to formula (I) has any one of the following structures ##STR00062## ##STR00063## wherein Cy denotes cyclohexyl, Ar.sup.F denotes 3,5-(CF.sub.3).sub.2C.sub.6H.sub.3, Ar.sup.Cl denotes 3,5-(Cl).sub.2C.sub.6H.sub.3, and Ar(F) denotes 3,5-(F).sub.2C.sub.6H.sub.3,
38-42. (canceled)
43. The catalytic process of claim 1, wherein the catalytic process is an alkene isomerisation, alkane transfer dehydrogenation and alkene dimerization.
44. The catalytic process of claim 1, wherein the C.sub.4-C.sub.10 hydrocarbon is an alkene comprising one or more CC bonds, and step a) results in the migration of the one or more CC bonds within the alkene.
45-48. (canceled)
49. The catalytic process of claim 1, wherein the C.sub.4-C.sub.10 hydrocarbon is an alkane, and step a) is conducted in the presence of a hydrogen acceptor, and wherein step a) results in the dehydrogenation of the alkane and the hydrogenation of the hydrogen acceptor.
50-53. (canceled)
54. The catalytic process of claim 1, wherein step a) results in the dimerization of two molecules of the C.sub.4-C.sub.10 hydrocarbon.
55. A compound having a structure according to formula (Ia) shown below: ##STR00064## wherein Bd is a bidentate ligand bonded to Rh via two heteroatoms independently selected from P, N and S, wherein the two heteroatoms are independently optionally substituted with one or more substituents selected from iso-propyl, tert-butyl, sec-butyl, n-pentyl, iso-pentyl, neo-pentyl, tert-pentyl, sec-pentyl, 3-pentyl, iso-propoxy, iso-butoxy, tert-butoxy, sec-butoxy, n-pentoxy, iso-pentoxy, neo-pentoxy, tert-pentoxy, sec-pentoxy, 3-pentoxy, 6-8 membered carbocyclyl, 6-8 membered heterocyclyl, aryl or adamantyl, any of which may be optionally substituted with one or more substituents selected from halo, oxo, hydroxyl, (1-4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl, (1-4C)alkoxy, (1-4C)haloalkyl and N(R.sub.x)(R.sub.y), wherein R.sub.x and R.sub.y are each independently selected from hydrogen and (1-4C)alkyl; each X is independently a ligand that is weakly bound to Rh via one or more bond, wherein the total energy of coordination of Rh to each X is <130 KJmol.sup.1, and wherein each X is selected from hydrogen, dinitrogen, a linear or branched (2-10C)alkene, a 5-10 membered cycloalkene, a linear or branched (6-10C)alkane and a 8-10 membered cycloalkane, any of which may be optionally substituted with one or more substituents selected from halo, oxo, hydroxyl, (1-4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl, (1-4C)alkoxy, (1-4C)haloalkyl and N(R.sub.v)(R.sub.w), wherein R.sub.v and R.sub.w are each independently selected from hydrogen and (1-4C)alkyl; n is 1, 2 or 3; Q is selected from B, Al, In and Ga; and each Ar is independently i. a phenyl group optionally substituted with one or more substituents selected from halo, (1-3C)alkyl and (1-3C)haloalkyl, or ii. a (1-3C)alkoxy group substituted with one or more substituents selected from halo, (1-3C)alkyl and (1-3C)haloalkyl.
56-58. (canceled)
59. The compound of claim 55, wherein n is 1 and X is selected from propene, butane, pentene, hexadiene and cyclooctene, and/or n is 2 and each X is independently selected from hydrogen, ethene and dinitrogen.
60-63. (canceled)
64. The compound of claim 55, wherein Bd is a bis-phosphine bidentate ligand, (i) wherein the bis-phosphine bidentate ligand has a structure according to formula (II) shown below: ##STR00065## wherein R.sub.a, R.sub.a, R.sub.b, and R.sub.b are each independently iso-propyl, tent-butyl, 6-8 membered carbocyclyl, aryl or adamantyl, any of which may be optionally substituted with one or more substituents selected from halo, hydroxyl, (1-4C)alkyl and (1-4C)alkoxy; and W is a (1-5C)alkylene linking group optionally substituted with one or more groups R.sub.c, wherein each R.sub.c is independently (1-4C)alkyl or (1-4C)alkoxy, and/or two groups R.sub.c may be linked, such that when taken with the atoms to which they are attached, they form a phenyl group optionally substituted with one or more substituents selected from halo, (1-4C)alkyl and (1-4C)alkoxy, and/or (ii) wherein the two P atoms in the bis-phosphine bidentate ligand are linked by a linking group selected from (1-5C)alkylene, (2-5C)alkenylene and (2-5C)alkynylene, any of which may be optionally substituted with one or more substituents selected from halo, oxo, hydroxyl, (1-4C)alkyl, (2-4C)alkenyl, (2-4C)alkynyl and (1-4C)alkoxy.
65. The compound of claim 55, wherein Q is B, Al or In.
66. The compound of claim 55, wherein Ar is either i) a phenyl group substituted at the 3-, 4- and/or 5-position with one or more substituents selected from halo (1-3C)alkyl and (1-3C)haloalkyl, or ii) a (1-3C)alkoxy group substituted with one or more substituents selected from halo (1-3C)alkyl and (1-3C)haloalkyl, and/or [QAr.sub.4] has any of the following structures: ##STR00066## wherein R.sub.p is fluoro, chloro or trifluromethyl.
67. (canceled)
68. The compound of claim 55, wherein the compound has any one of the following structures ##STR00067## wherein Cy denotes cyclohexyl and Ar.sup.F denotes 3,5-(CF.sub.3).sub.2C.sub.6H.sub.3.
69-73.(canceled)
Description
MATERIALS AND METHODS
[0323] All manipulations (unless otherwise stated) were performed under an atmosphere of argon, using standard Schlenk techniques on a dual vacuum/inlet manifold or by employment of an MBraun glovebox. Glassware was dried in an oven at 130 C. overnight prior to use. Pentane, hexane and CH.sub.2Cl.sub.2 were dried using an MBraun SPS-800 solvent purification system and degassed by three freeze-pump-thaw cycles. CD.sub.2Cl.sub.2 and C.sub.6H.sub.5F were both dried by stirring over CaH.sub.2 overnight before being vacuum distilled and subsequently degassed by three freeze-pump-thaw cycles. 1,2-F.sub.2C.sub.6H.sub.4 was stirred over Al.sub.2O.sub.3 for two hours then over CaH.sub.2 overnight overnight before being vacuum distilled and subsequently degassed by three freeze-pump-thaw cycles. Ethylene, propylene and but-1-ene were all supplied by CK gases. Propylene-d.sub.3 was supplied by Cambridge isotopes laboratory.
[0324] Solution NMR data were collected on either a Brucker AVD 500 MHz or a Bruker Ascend 400 MHz spectrometer at room temperature unless otherwise started. Non-deuterated solvents were locked to standard CD.sub.2Cl.sub.2 solutions. Residual protio solvent resonances were used as a reference for .sup.1H NMR spectra. A small amount of CD.sub.2Cl.sub.2 was added as a reference for .sup.2H{.sup.1H} NMR spectra. .sup.31P{H} NMR spectra were referenced externally to 85% H.sub.3PO.sub.4. All chemical shifts () are quoted in ppm and coupling constants in Hz.
[0325] .sup.1H/.sup.13C solid state NMR (SSNMR) spectra (including two dimensional measurements) were obtained on a Bruker Avance III HD spectrometer equipped with a 9.4 Tesla magnet, operating at 399.9 MHz for .sup.1H and 100.6 MHz for .sup.13C using 4 mm O.D. rotors containing approximately 70 mg of sample and a MAS rate of 10 kHz. Powdered microcrystalline samples were prepared by grinding using the back of a spatula in a glovebox and subsequently loaded into 4 mm rotors. Hydrogenation and deuteration reactions were undertaken by exposing the open rotors in a J. Young's flask to an atmosphere (2 atm) of H.sub.2/D.sub.2 respectively before removal of the atmosphere and capping the rotors in a glovebox. For .sup.13C CP/MAS a sequence with a variable X-amplitude spin-lock pulse.sup.1 and spinal64 proton decoupling was used. 4500 transients were acquired using a contact time of 2.5 ms, an acquisition time of 25 ms (2048 data points zero filled to 32 K) and a recycle delay of 2 s. All .sup.13C spectra were referenced to adamantane (the upfield methine resonance was taken to be at =29.5 ppm.sup.2 on a scale where (TMS)=0 ppm as a secondary reference. For the fslg-HETCOR,.sup.3 128 transients (2048 data points in F2) and 80 increments in F1 (zero filled to 4k1k) were acquired with a contact time 0.4 ms and a recycle delay of 5 s. .sup.31 P{.sup.1H} spectra were reference externally to 85% H.sub.3PO.sub.4. Low temperature measurements were undertaken using standard Bruker variable temperature set-up.
[0326] Gas phase .sup.1H NMR spectroscopy was carried out using a Bruker Ascend 400 MHz spectrometer. The T1 delay was set to 1 s, and this has been previously shown to allow for the accurate comparison of integrals. Samples were loaded into a high-pressure NMR tube sealed with a Teflon stopcock, before being transferred to a Schlenk vacuum line, evacuated and then loaded with the gaseous reagents (via a custom made glass T-piece adaptor). The spectrometer was locked and shimmed to a separate CD.sub.2Cl.sub.2 sample in a similar bore tube, the sample was then replaced and spectra run. For isomerisation catalytic runs the machine was locked and shimmed before the gaseous reagents were added (full experimental details of isomerization catalysis are below).
[0327] Electrospray ionisation mass spectrometry (ESI-MS) was carried out using a Bruker MicrOTOF instrument directly connected to a modified Innovative Technology glovebox..sup.4 Typical acquisition parameters were used (sample flow rate: 4 L min.sup.1, nebuliser gas pressure: 0.4 bar, drying gas: Argon at 333 K flowing at 4 L min.sup.1, capillary voltage: 4.5 kV, exit voltage: 60 V). The spectrometer was calibrated using a mixture of tetraalkyl ammonium bromides [N(C.sub.nH.sub.2n+1).sub.4]Br (n=2-8, 12, 16 and 18). Samples were diluted to a concentration of 110.sup.6 M in the appropriate solvent before sampling by ESI-MS.
[0328] Single crystal X-ray diffraction data for all samples were collected as follows: a typical crystal was mounted on a MiTeGen Micromounts using perfluoropolyether oil and cooled rapidly to 150 K in a stream of nitrogen gas using an Oxford Cryosystems Cryostream unit..sup.5 Data were collected with an Agilent SuperNova diffractometer (Cu K radiation, =1.54180 ). Raw frame data were reduced using CrysAlisPro..sup.6,7 The structures were solved using SuperFlip.sup.8 and refined using full-matrix least squares refinement on all F.sup.2 data using the CRYSTALS program suite..sup.9, 10 In general distances and angles were calculated using the full covariance matrix. Dihedral angles were calculated using PLATON..sup.11
[0329] Isomerisation runs were carried out in the gas phase by loading a high pressure NMR tube (of known volume) with a crystalline sample of the catalyst in an argon-filled glovebox. The tubes were sealed by a Teflon stopcock and transferred to a Schlenk line fitted with a custom-built glass T-piece adaptor, allowing for exposure to vacuum/argon on one side, and the reagent gas on the other side. The T-piece and connecting tubing were thrice pumped and refilled with argon, then thrice pumped and refilled with but-1-ene, before being evacuated (<110.sup.2 mbar) and subsequently opening the Teflon stopcock on the NMR tube (thus exposing the argon-filled tube to dynamic vacuum). During this final evacuation the NMR machine was prepared by locking and shimming to a sample of CD.sub.2Cl.sub.2 in a similar bore NMR tube. The sample was then refilled with but-1-ene gas as a timer was simultaneously started. The tube was sealed and transferred to the NMR machine as quickly as possible. The first data collection was immediately started. The extent of conversion was measured by the comparison of the integral of the two alkene resonances of but-2-ene and the alkyl CH.sub.2 resonance of but-1-ene. These have been previously shown to be comparable by gas phase NMR. TON and TOF are calculated assuming that all site are equally catalytically active, and are therefore, a minimum number. Intuitively surface sites would be more active than those at the centre of the bulk by a simple mass transit argument.
Example 1
Synthesis and Characterisation of Rh Complexes
1.1Synthesis and characterisation of [(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)Rh(.SUP.2.:.SUP.2.-C.SUB.7.H.SUB.12.)][BAr.SUP.F..SUB.4.] ([1-NBA][BAr.SUP.F..SUB.4.])
[0330] ##STR00032##
[0331] One Schlenk flask was charged with [Rh(COD).sub.2][BAr.sup.F.sub.4] (500 mg, 0.423 mmol) and another was filled with Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2 (180 mg, 0.426 mmol). Both solids were dissolved in CH.sub.2Cl.sub.2 (30 ml each) and the phosphine was added to [Rh(COD).sub.2][BAr.sup.F.sub.4] with vigorous stirring. The solution was allowed to stir for one hour before the solvent was removed in vacuo. The subsequent solid was washed with pentane (320 ml) before being taken up in C.sub.6H.sub.5F (30 ml) and filtered via cannula into a Young's flask. The solution was freeze-pump-thaw degassed three times then H.sub.2 gas was added (1 bar). The solution was allowed to stir for four hours before the H.sub.2 and solvent was removed in vacuo. The remaining solidwas washed with pentane (320m1) then taken up in CH.sub.2Cl.sub.2 (50 ml) and filtered via cannula into a Schlenk flask. This solution was stirred vigorously and an excess of norbornadiene was added (0.6 ml, 5.904 mmol) and the solution darkened over 15 minutes to a blood-orange red. The solvent was removed in vacuo and excess norbornadiene and C.sub.6H.sub.5F were removed by washing with pentane (320 ml) before the resultant solid was taken up in the minimum volume of CH.sub.2Cl.sub.2 and filtered into a Young's crystallization tube and layered with pentane. Yield 370 mg (59%). [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.8)][BAr.sup.F.sub.4]. Hydrogenation (1 atm) of a crystalline sample of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.8)][BAr.sup.F.sub.4] led to the quantitative formation of [1-NBA][BAr.sup.F.sub.4] after five minutes. The crystalline sample goes opaque but there is little other colour change.
[0332] .sup.31P{.sup.1H} SS-NMR (162 MHz, 10 kHz spin rate): 110.5 (two overlapping d, J.sub.Rh-P1=207 Hz, J.sub.Rh-P2=216 Hz). .sup.13C{.sup.1H} SS-NMR (101 MHz, 10 kHz spin rate): 163.18 (br, BAr.sup.F.sub.4), 134.54 (br, BAr.sup.F.sub.4), 129.80 (br, BAr.sup.F.sub.4), 124.30 (br, BAr.sup.F.sub.4), 118.19 (br, BAr.sup.F.sub.4), 115.84 (br, BAr.sup.F.sub.4), 43.71, 39.65, 38.98, 35.95, 35.34, 31.86, 31.20, 30.17, 29.01, 26.90, 25.33, 20.69 (multiple aliphatic resonances). .sup.1H projection from .sup.1H/.sup.13C Frequency Switched LeeGoldburg HECTOR SS-NMR: 8.09 (sh), 7.10 (m, br), 0.83 (s), 1.82 (w). .sup.13C projection from .sup.1H/.sup.13C Frequency Switched LeeGoldburg HECTOR SS-NMR: 134.80, 130.00, 118.60, 116.00, 44.10, 39.50, 36.00, 30.70, 27.40, 25.50, 21.40. Elemental analysis found (calculated): C 52.46 (52.55) H 4.80 (4.89)
1.2Synthesis and characterisation of [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(.SUP.2.C.SUB.2.H.SUB.4.).SUB.2.][BAr.SUP.F..SUB.4.] ([1-(ethene).SUB.2.][BAr.SUP.F..SUB.4.])
[0333] ##STR00033##
Attempted Solution Phase Synthesis
[0334] A crystalline sample of [(Cy.sub.2PCH.sub.2CH.sub.2FCy.sub.2)Rh(.sup.6-F.sub.2C.sub.6H.sub.4)][BAr.sup.F.sub.4] ([.sup.1-C.sub.6H.sub.4F.sub.2][BAr.sub.F4].sup.13) (25 mg, 0.0166 mmol) was taken up in CD.sub.2Cl.sub.2 (0.5 ml) in a high pressure NMR tube. This was freeze-pump-thaw degassed (<110.sup.2 mbar) three times before ethylene gas (1 bar) was added. An immediate darkening of the yellow solution to orange occurred. .sup.31P{.sup.1H} NMR spectroscopy indicated that near quantitative conversion to [1-(ethene).sub.2][BAr.sup.F.sub.4] had occurred after 15 minutes (
Solid state synthesis of octahedral [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(.SUP.2.-C.SUB.2.H.SUB.4.).SUB.2.][BAr.SUP.F..SUB.4.] ([1-(ethene).SUB.2.][BAr.SUP.F..SUB.4.]-Oct)
[0335] To an orange sample of crystalline [1-NBA][BAr.sup.F.sub.4] (25 mg, 0.0168 mmol) in an evacuated (<110.sup.2 mbar) J Young's flask (c. 50 ml) ethylene gas (1 bar, 298 K) is added and left standing overnight. Little colour change is observed, though the crystals take on the appearance of liquid on the surface assumed to be norbornane. It is not possible to remove the residual norbornane (attempts to do so by washing with pentane did not work), however the synthesis goes in >95% yield by .sup.31P{.sup.1H} solid state NMR spectroscopy and .sup.31P{.sup.1H} solution NMR spectroscopy when dissolved up in CD.sub.2Cl.sub.2 (the only other signal being due to an uncharacterised decomposition product, which mass spectroscopic evidence suggests a product of CH.sub.2Cl.sub.2 activation). After 16 hours in CD.sub.2Cl.sub.2 the compound decomposes to a range of products. Dissolving the product in difluorobenzene results in the formation of [1-C.sub.6H.sub.4F.sub.2][BAr.sup.F.sub.4].
Solid state synthesis of hexagonal [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(.SUP.2 .-C.SUB.2.H.SUB.4.).SUB.2.][BAr.SUP.F..SUB.4.] ([1-(ethene).SUB.2.][BAr.SUP.F..SUB.4.]-Hex)
[0336] To an orange sample of crystalline [1-NBA][BAr.sup.F.sub.4] (100 mg, 67.3 mol) in an evacuated (<110.sup.2 mbar) J Young's flask (c. 50 ml) ethylene gas (1 bar, 298 K) is added and left standing overnight, to form [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct. Working under an atmosphere of ethylene (1 bar), the sample is then dissolved in a minimum volume of freshly degassed CH.sub.2Cl.sub.2 before quick filtration via cannula and layering with freshly degassed pentane. The sample is then stored at 78 C. and allowed to crystallise over at least a week. Single crystals, directly selected from the mother liquor, are suitable for X-ray diffraction analysis, however attempts to isolate the bulk sample resulted in the loss of crystallinity. Nevertheless solution NMR data are identical to [1-(ethene).sub.2][BAr.sup.F.sub.4] confirming the loss of long range order is not due to the loss of ethylene. Due to the limited amount of crystalline material obtained solid-state NMR spectroscopy was not undertaken. Isolated yield on the non-crystalline material: 77 mg (53.3 mol, 79.2%).
Characterisation data for [1-(ethene).SUB.2.][BAr.SUP.F..SUB.4.]
[0337]
[0338] .sup.1H solution NMR (CD.sub.2Cl.sub.2, 298 K, 400 MHz) : 7.72 (8H, s, o-BAr.sup.F.sub.4), 7.56 (4H, s, p-BAr.sup.F.sub.4), 4.43 (8H, v br, v.sub.1/2=94 Hz, ethylene), 2.0-1.0 ppm (multiple overlapping aliphatic resonances).
[0339] .sup.31P{.sup.1H} solution NMR (CD.sub.2Cl.sub.2, 298 K, 162 MHz) : 73.7 (v. br, v.sup.1/2500 Hz).
[0340] .sup.1H solution NMR (CD.sub.2Cl.sub.2, 193 K, 400 MHz) : 7.71 (8H, s, o-BAr.sup.F.sub.4), 7.54 (4H, s, p-BAr.sup.F.sub.4), 4.15 (8H, s, ethylene), 2.0-1.0 ppm (multiple overlapping aliphatic resonances).
[0341] .sup.31P{.sup.1H} solution NMR (CD.sub.2Cl.sub.2, 193 K, 162 MHz) : 73.6 (d, J.sub.RhP=145 Hz).
[0342] .sup.31P{.sup.1H} solid state NMR (for [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct; 162 MHz, 10 kHz spin rate) : 73.7 (br, v.sup.1/2410 Hz).
[0343] .sup.13C{.sup.1H} solid state NMR (for [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct; 101 MHz, 10 kHz spin rate) : 164.0 (BAr.sup.F.sub.4), 134.7 (BArF4), 130.4 (BAr.sup.F.sub.4), 125.3 (BAr.sup.F.sub.4), 117.2 (BAr.sup.F.sub.4), 82.23 (Ethylene) 15-40 (multiple overlapping aliphatic resonances).
[0344] Mass Spec found (calc.): 581.2189 (581.2907) note: there is considerable presence of [1-butadiene][BAr.sup.F.sub.4] and decomposition product of formula m/z=[{(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Rh}Cl.sub.2].sup.2+-H.sub.2. There is no evidence for [1-butadiene][BAr.sup.F.sub.4] in bulk samples so it is assumed to form via an in-situ ESI-MS process.
[0345] Elemental analysis found (calc.) (carried out with a sample of [1-(ethene).sub.2][BAr.sup.F.sub.4]-Hex): C 51.37% (51.51%), H 4.74% (4.63%). Satisfactory Elemental analysis for [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct has not been attained due to persistent contamination with excess norbornane.
[0346] Crystal structure: The transformation from [1-NBA][BAr.sup.F.sub.4] to [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct is also a singlecrystal to single-crystal one, as shown by an X-ray structure determination at 150 K; and starting from [1-NBD][BAr.sup.F.sub.4] this represents a rare example of a sequential reaction sequence for such processes..sup.37 It is believed that the CF.sub.3 groups on the anions results in some plasticity in the solidstate lattice, which allows for the movement of the NBA,.sup.38 given that there are no clear channels in the crystal lattice. There is a space group change from to P21/n (Z=4) in [1-NBA][BAr.sup.F.sub.4] to C2/c (Z=4) in [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct on substitution.
[0347]
[0348] In the transformation from [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct to [1-(ethene).sub.2][BAr.sup.F.sub.4]Hex, the space group change is from monoclinic C2/c (Z=4) to hexagonal P6.sub.322 (Z=6).
[0349]
[0350] It is noted that the structure of [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct has an elevated R-factor, as well as a low full .sub.max value. This is primarily due to a loss in high angle datawhich is rationalised by the synthetic route (single-crystal to single-crystal to single-crystal!) putting strain on the lattice. For [1-(ethene).sub.2][BAr.sup.F.sub.4]-Hex no such loss of data is presented, however the CheckCif output contains one A alert due to the very large voids in the structure.
[0351] 1.3Synthesis and characterisation of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)(.sup.2-C.sub.3H.sub.6)][BAr.sup.F.sub.4] ([1-propene][BAr.sup.F.sub.4])
##STR00034##
Attempted Solution Phase Synthesis
[0352] A crystalline sample of [1-C.sub.6H.sub.4F.sub.4][BAr.sup.F.sub.4] (25 mg, 0.0166 mmol) was taken up in CD.sub.2Cl.sub.2 (0.5 ml) in a high pressure NMR tube. This was freeze-pump-thaw degassed (<110.sup.2 mbar) three times before propylene gas (1 bar) was added. No discernible (by eye) colour change occured. .sup.31P{.sup.1H} NMR spectroscopy indicated that very little conversion to [1-propene][BAr.sup.F.sub.4] had occurred, with the bulk of the material remaining as the starting [1-C.sub.6H.sub.4F.sub.4][BAr.sup.F.sub.4]. Any attempted work-up involving a vacuum results in either starting material or the complete decomposition of the species, to presumed solvent (CH or CCl) activated products (indicated from mass spectroscopy showing the presence of chloride-bridged rhodium dimers). Furthermore leaving [1-propene][BAr.sup.F.sub.4] in CH.sub.2Cl.sub.2 solution, at room temperature, resulted in similar decomposition over a period of approximately half an hour. To date it has not been possible to isolate [1-propene][BAr.sup.F.sub.4] via solution methods.
Solid state synthesis of [1-propene][BAr.SUP.F..SUB.4.]
[0353] To an orange sample of crystalline [1-NBA][BAr.sup.F.sub.4] (25 m, 0.0168 mmol) in an evacuated (<110.sup.2 mbar) J Young's flask (c. 50 ml) propylene gas (1 bar, 298 K) is added and left standing overnight. Little colour change is observed, but evidence of a colourless liquid/oil is sometimes observed on the sides of the flask (assumed to be liberated NBA)it is this sample that was used for spectroscopic analysis. Under a propene atmosphere this compound appears stable for at least 72 hours at room temperature (shown by .sup.31P{.sup.1H} solid state NMR). The long-term stability under an argon atmosphere has not been investigated. Attempts to recrystallize the material by dissolving in CH.sub.2Cl.sub.2 led to (presumably solvent induced) decomposition over the period of 30 mins (at room temperature). Dissolving the material in difluorobenzene resulted in the formation of [1-C.sub.6H.sub.4F.sub.2][BAr.sup.F.sub.4]. In light of this attempts to recrystallize have been met with failure, and, because of the contamination of norbornane, it has not been possible to attain an acceptable elemental analysis. Yield: Quantitative (>95%) by .sup.31P{.sup.1H} solution and solid state NMR (no other signals observed).
Characterisation of [1-propene](BAr.SUP.F..SUB.4.]
[0354] .sup.1H solution NMR (CD.sub.2Cl.sub.2, 500 MHz, 298 K) : 7.72 (8H, s o-BAr.sup.F.sub.4), 7.56 (4H, s, p-BAr.sup.F.sub.4), 5.07 (v br, propene), 2.10-1.00 (multiple overlapping aliphatic resonance, i.e. a forest).
[0355] .sup.31P{.sup.1H} solution NMR (CD.sub.2Cl.sub.2, 202 MHz, 298 K) : 95.2 (br d, J.sub.RhP=181 Hz).
[0356] .sup.1H solution NMR (CD.sub.2Cl.sub.2, 500 MHz, 193 K) : 7.71 (8H, s, o-BAr.sup.F.sub.4), 7.54 (4H, s, p-BAr.sup.F.sub.4), 4.84 (1H, br, propylene), 4.54 (1H, br, propene), 3.55 (1H, br, propene), 2.02-0.94 (multiple overlapping aliphatic resonances), -0.02 (3H, br, propene agostic CH.sub.3).
[0357] .sup.31P{.sup.1H} solution NMR (CD.sub.2Cl.sub.2, 202 MHz, 193 K) : 100.4 (br, J.sub.RhP=200 Hz), 89.9 (br, J.sub.RhP=161 Hz).
[0358] .sup.31P{.sup.1H} solid state NMR (162 MHz, 298 K, 10 kHz spin rate) : 95.6 (asym. br. s, v.sub.1/2=503 Hz).
[0359] .sup.31P{.sup.1H} solid state NMR (162 MHz, 158 K, 10 kHz spin rate) : 101.3 (br, v.sub.1/2=510 Hz), 90.4 (br, v.sub.1/2=463 Hz).
[0360]
[0361] .sup.13C{.sup.1H} solid state NMR (101 MHz, 298 K, 10 kHz spin rate) : 164.0 (BAr.sup.F.sub.4), 134.4 (BAr.sup.F.sub.4), 130.4 (BAr.sup.F.sub.4), 124.5 (BAr.sup.F.sub.4), 118.4 (BAr.sup.F.sub.4), 116.9 (BAr.sup.F.sub.4), 93.7 (v. br, v.sub.1/2=582 Hz), 46-15 (multiple overlapping aliphatic resonances).
[0362] .sup.13C{.sup.1H} solid state NMR (101 MHz, 158 K, 10 kHz spin rate) : 163.7 (BAr.sup.F.sub.4), 133.8 (BAr.sup.F.sub.4), 130.1 (BAr.sup.F.sub.4), 124.6 (BAr.sup.F.sub.4), 118.4 (BAr.sup.F.sub.4), 116.1 (BAr.sup.F.sub.4), 94.2 (Propene CC), 78.8 (Propene CC), 46-15 (multiple aliphatic resonances), 6.5 (Propene agostic CH.sub.3).
[0363]
[0364] H/D scrambling in [1-propylene-D.sub.3][BAr.sup.F.sub.4]: In an effort to elucidate the precise mechanism of isomerisation of but-1-ene, model experiments were carried out using propylene-D3. [1-NBA][BAr.sup.F.sub.4] (20 mg, 0.0135 mmol) was loaded into a high pressure NMR tube in an argon-filled glovebox. This was then sealed using a Teflon stop-cock, before transferring to a Schlenk-line and evacuated. The tube was refilled with propylene-D.sub.3 (1 bar). The head space was then monitored using gas-phase .sup.2H{.sup.1H} NMR.
##STR00035##
[0365]
[0366] Mass Spec: Not stable under mass spectrometric conditions. Species observed (with appropriate isotopic distributions) at m/z=[{(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Rh}.sub.2CH.sub.4Cl.sub.2].sup.2+; RCy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Rh(C.sub.4H.sub.8)].sup.+;[(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Rh(C.sub.5H.sub.6)].sup.+;[(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Rh(C.sub.6H.sub.6)].sup.+.
[0367] Crystal structure:
[0368] Similarly to [(1-ethene).sub.2][BAr.sup.F.sub.4]-Oct there is a somewhat elevated R-factor and a low emax value, again due to the loss of high angle data due to crystal quality degrading due to sequential single-crystal to single-crystal transformation.
1.4Synthesis and characterisation of [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(.SUP.2.-C.SUB.4.H.SUB.8.)][BAr.SUP.F..SUB.4.] ([1-butene][BAr.SUP.F..SUB.4.])
[0369] ##STR00036##
Attempted Solution Phase Synthesis
[0370] A sample of [1-C.sub.6H.sub.4F.sub.2][BAr.sup.F.sub.4] (20 mg, 0.0133 mmol) was taken up in CH.sub.2Cl.sub.2 before being freeze-pump-thawed degassed three times and but-1-ene (1 bar) was added. The yellow solution immediately turned orange, and continued to go deeper in colour. It was shown (via .sup.31P{.sup.1H} solution NMR spectroscopy), conversion to [1-butadiene][BAr.sup.F.sub.4] would occur over the period of one hour in solution.
Solid state synthesis of [1-butene](BAr.SUP.F..SUB.4.]
[0371] In order to attain spectroscopic data for [1-butene][BAr.sup.F.sub.4] but-1-ene gas (1 bar) is added to an orange sample of crystalline [1-NBA][BAr.sup.F.sub.4] (20 mg) in a high pressure NMR tube at room temperature. The solid is allowed to stand for 5 minutes and then is exposed to a dynamic vacuum for 3 minutes (<110.sup.2 mbar). The sample is then dissolved up in CD.sub.2Cl.sub.2 and NMR data immediately recorded. The dehydrogenation to produce the butadiene complex is considerably quicker in solution than in the solid state.
Characterisation of [1-butene](BAr.SUP.F..SUB.4.]
[0372] .sup.31P{.sup.1H} solution NMR (CD.sub.2Cl.sub.2, 202 MHz, 298 K) : 95.4 (br. d, J.sub.RhP=169 Hz).
[0373] .sup.31P{.sup.1H} solid state NMR (162 MHz, 298 K, 10 kHz spin rate) : 98.4 (br), 95.1 (br).
[0374] .sup.13C{.sup.1H} solid state NMR (101 MHz, 298 K, 10 kHz spin rate) : 164.3 (BAr.sup.F.sub.4), 134.9 (BAr.sup.F.sub.4), 130.3 (BAr.sup.F.sub.4), 125.1 (BAr.sup.F.sub.4), 120.6 (BAr.sup.F.sub.4), 118.6 (BAr.sup.F.sub.4), 116.7 (BAr.sup.F.sub.4), 91.8 (br, butene), 42-15 (multiple overlapping aliphatic resonances), 6.3 (br, butene agostic).
[0375] Mass Spec found (calc.): Under mass spectral conditions the only identifiable signal is due to [1-butadiene][BAr.sup.F.sub.4].
[0376] Identification of isomer of butene in [1-butene][BAr.sup.F.sub.4]: In order to determine which isomer of butane (but-1-ene or but-2-ene) is present in the complex [1-butene][BAr.sup.F.sub.4] in the solid state (and thus imply the resting state of the isomerisation catalysis) labelling studies were conducted (Scheme 3). [1-butene][BAr.sup.F.sub.4] was made in-situ by addition of but-1-ene (1 bar) to [1-NBA][BAr.sup.F.sub.4] (30 mg, 0.0202 mmol) in a high pressure NMR tube. This was allowed to stand for 5 minutes, before subjection to vacuum to remove excess but-1-ene gas (cycled three time), and then D.sub.2 gas was added (1 bar, to form butane-D.sub.2). The deuterated material was dissolved up in CH.sub.2Cl.sub.2 and .sup.2H{.sup.1H} solution NMR was used to identify the locations of the deuterium atoms.
[0377]
1.5Synthesis and characterisation of [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(.SUP.2..SUP.2.-C.SUB.4.H.SUB.6.)][BAr.SUP.F..SUB.4.] ([1-butadiene][BAr.SUP.F..SUB.4.]) (comparative example)
[0378] ##STR00037##
Synthesis of [1-butadiene](BAr.SUP.F..SUB.4.]
[0379] To an orange sample of crystalline [1-NBA][BAr.sup.F.sub.4] (50 mg, 0.0333 mmol) in a J. Young's flask (c. 100 ml), but-1-ene gas (1 bar) is added and left standing for six hours. Over this time the sample goes a deep burgundy colour. Though crystallinity appears to be retained considerable data loss occurs (for single crystal X-ray diffraction), especially at high angle, and even getting absolute connectivity is not possible. .sup.31P{.sup.1H} solution NMR on the dissolved sample showed the product to be formed quantitatively and to be chemically identical to that produced by solution route.
Characterisation of [1butadiene](BAr.SUP.F..SUB.4.]
[0380] .sup.1H solution NMR (CD.sub.2Cl.sub.2, 500 MHz) : 7.72 (8H, s, o-BArF4), 7.56 (4H, s, p-BArF4), 5.47 (2H, br t, C2/C3, J.sub.HH9 Hz), 4.51 (2H, br d, C1/C4, J.sub.HH=6 Hz), 2.83 (2H, d, C1/C4, J.sub.HH=14 Hz).
[0381] .sup.31P{.sup.1H} solution NMR (CD.sub.2Cl.sub.2, 202 MHz) : 82.0 (d, J.sub.RhP=169 Hz).
[0382] .sup.31P{.sup.1H} solid state NMR : 81.0 (asym. br.).
[0383] .sup.13C{.sup.1H} solid state NMR : 164.3 (BAr.sup.F.sub.4), 134.4 (BAr.sup.F.sub.4), 130.3 (BAr.sup.F.sub.4), 125.1 (BAr.sup.F.sub.4), 118.6 (BAr.sup.F.sub.4), 116.7 (BAr.sup.F.sub.4), 103.5 (butadiene), 99.6 (butadiene), 87.8 (butadiene), 63.2 (butadiene), 42-15 (multiple overlapping aliphatic resonances).
[0384] Mass Spec found (calc.): 579.2733 (579.2750). Note considerable signal (with appropriate isotopic distribution) at m/z=[(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Rh(C.sub.2H.sub.4)].sup.+; [(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Rh(C.sub.6H.sub.10)].sup.+; [(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Rh(C.sub.7H.sub.12)].sup.+.
1.6Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.3.PCy.SUB.2.)(.SUP.2.:.SUP.2.-C.SUB.8.H.SUB.12.)][BAr.SUP.F..SUB.4.]
[0385] ##STR00038##
Synthesis
[0386] One Schlenk flask was charged with [Rh(cod).sub.2][BAr.sup.F.sub.4] (350 mg, 0.296 mmol) and dissolved in CH.sub.2Cl.sub.2 (5 mL). Then Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2 (1.5 mL, 0.2 M solution in C.sub.6H.sub.4F, 0.3 mmol) was added dropwise with vigorous stirring. The resulting light orange solution was allowed to stir for two hours at room temperature before the solvent was partially removed in vacuo (2 mL) and n-pentane (25 mL) was added. The resulting orange solid was filtered via cannula, washed with pentane (35 mL), and dried in vacuo to give [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2:.sup.2-C.sub.8H.sub.12)][BAr.sup.F.sub.4] as an orange solid. Yield: 400 mg, 0.264 mmol, 89%.
Characterisation
[0387] .sup.1H solution NMR (400.1 MHz, CD.sub.2Cl.sub.2, 298K): 7.76 (br s, 8 H, BAr.sup.F), 7.60 (s, 4H, BAr.sup.F), 5.07 (br s, 4 H, C.sub.8H.sub.12), 2.38-2.22 (m, 12H, C.sub.8H.sub.12+phosphine), 1.96-1.79 (m, 22H, C.sub.8H.sub.12+phosphine), 1.51 (m, 4H, phosphine or C.sub.8H.sub.12), 1.42-1.10 (m, 20H, C.sub.8H.sub.12+phosphine). .sup.11B{.sup.1H} solution NMR (128.4 MHz, CD.sub.2Cl.sub.2, 298K): -6.5 (s). .sup.19F{.sup.1H} solution NMR (376.5 MHz, CD.sub.2Cl.sub.2, 298K): -62.9 (s). .sup.31P{.sup.1H} solution NMR (162.0 MHz, CD.sub.2Cl.sub.2, 298K): 12.6 (d, J.sub.RhP2=139 Hz). Elemental analysis found (calculated) for C.sub.67H.sub.74P.sub.2F.sub.24BRh: C, 53.26 (53.37); H, 4.94 (4.91).
1.7Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.3.PCy.SUB.2.)(.SUP.2.:.SUP.2.-C.SUB.7.H.SUB.8.)]]BAr.SUP.F..SUB.4.]
[0388] ##STR00039##
Synthesis
[0389] One Young's flask was charged with [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2:.sup.2-C.sub.8H.sub.12)][BAr.sup.F.sub.4] (145 mg, 0.096 mmol) and dissolved in 1,2-F.sub.2C.sub.8H.sub.4 (3 mL). The orange solution was freeze-pump-thaw degassed three times before H.sub.2 gas (1 bar) was added. The reaction mixture was allowed to stir for one hour resulting in lighter orange solution, and then H.sub.2 and solvent were removed in vacuo. The resulting solid was washed with pentane (310 mL) and dissolved in CH.sub.2Cl.sub.2 (5 mL). Addition of an excess of norbornadiene (0.14 mL, 1.344 mmol) and stirring for one hour resulted in the darkening of the solution. The solvent was partially removed under vacuum (3.0 mL) and the resulting solution was filtered via cannula into a Young's crystallization tube. Crystals of [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.8)][BAr.sup.F.sub.4] were obtained by layering the resulting solution with n-pentane. Yield: 96 mg, 0.063 mmol, 66%.
Characterisation
[0390] .sup.1H solution NMR (400.1 MHz, CD.sub.2Cl.sub.2, 298K): 7.72 (br s, 8H, BAr.sup.F), 7.56 (s, 4H, BAr.sup.F), 5.16 (br s, 4H, C.sub.7H.sub.8), 4.10 (s, 2 H, C.sub.7H.sub.8), 2.21 (overlapped br s, 2H each, C.sub.7H.sub.8), 1.96-1.73 (m, 26H, phosphine), 1.52 (m, 4H, phosphine), 1.40-1.17 (m, 20H, phosphine). .sup.11B{.sup.1H} solution NMR (128.4 MHz, CD.sub.2Cl.sub.2, 298K): -6.5 (s). .sup.19F{.sup.1H} solution NMR (376.5 MHz, CD.sub.2Cl.sub.2, 298K): -62.9 (s). .sup.31P{.sup.1H} solution NMR (202.4 MHz, CD.sub.2Cl.sub.2, 298K): 15.7 (d, J.sub.RhP2=147 Hz). Elemental analysis found (calculated) for C.sub.66H.sub.70B.sub.1F.sub.24F.sub.2Rh.sub.1: C, 53.03 (52.92); H, 4.72 (4.55).
1.8Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.3.PCY.SUB.2.)(.SUP.2.:.SUP.2.-C.SUB.7.H.SUB.12.)][BAr.SUP.F..SUB.4.]
[0391] ##STR00040##
Synthesis
[0392] Addition of H.sub.2 gas (1 bar) to a crystalline samples of [Rh(Cy.sub.2P(CH.sub.2).sub.3PCY.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.8)][BAr.sup.F.sub.4] led to the quantitative formation of [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4] after 5 minutes. The crystalline sample goes opaque and dark upon hydrogenation.
Characterisation
[0393] Single crystal X-ray raw data were collected at 150 K using an Agilent SuperNova diffractometer (Cu K radiation, =1.54180 ). Collected crystal lattice parameters: monoclinic (P2/n), a=19.07172(10), b=17.81061(10), c=19.83810(10), =92.2275(5), V=6733.49(6), Z=4.
1.9Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.3.PCy.SUB.2.)(.SUP.2.-propene)][BAr.SUP.F..SUB.4.]
[0394] ##STR00041##
Synthesis
[0395] Addition of propene gas (1 bar) to a crystalline samples of [Rh(Cy.sub.2P(CH.sub.2).sub.3PCY.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.8)][BAr.sup.F.sub.4] led to the quantitative formation of [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2-Propene)][BAr.sup.F.sub.4] after eight hours. The crystalline sample becomes light orange.
Characterisation
[0396] Single crystal X-ray raw data were collected at 100 K using a Rigaku 007 HF (High Flux) diffractometer (Cu K radiation, =1.54180 ) equipped with a HyPix-600HE detector. Collected crystal lattice parameters: monoclinic (C2/c), a=19.2343(14), b=16.7377(11), c=20.0147(10), =91.134(5), V=6442.2(7) .sup.3, Z=4.
1.10Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.3.PCy.SUB.2.)(.SUP.2.:.SUP.2.-C.SUB.8.H.SUB.12.)][BAr.SUP.F..SUB.4.]
[0397] ##STR00042##
Synthesis
[0398] Addition of H2 gas (1 bar) to a crystalline samples of [Rh(Cy.sub.2P(CH.sub.2).sub.3PCY.sub.2)(.sup.2:.sup.2-C.sub.8H.sub.12)PAr.sup.F.sub.4] led to the quantitative formation of RRh(Cy.sub.2P(CH.sub.2).sub.3PCY.sub.2)(.sup.2:.sup.2-C.sub.8H.sub.14)][BAr.sup.F.sub.4] after 30 mins. The crystalline sample goes opaque and dark orange upon hydrogenation.
Characterisation
[0399] Single crystal X-ray raw data were collected at 150 K using an Agilent SuperNova diffractometer (Cu K radiation, =1.54180 ). Collected crystal lattice parameters: triclinic (P-1), a=13.0186(7), b=13.1664(7), c=20.1179(3), =87.719(3), =87.838(3), =86.484(4), V=3437.0(3) .sup.3, Z=2.
1.11Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.4.PCy.SUB.2.)(.SUP.2.:.SUP.2.-C.SUB.8.H.SUB.12.)][BAr.SUP.F..SUB.4.]
[0400] ##STR00043##
Synthesis
[0401] One Schlenk flask was charged with [Rh(cod).sub.2][BAr.sup.F.sub.4] (270 mg, 0.228 mmol) and another filled with Cy.sub.2P(CH.sub.2).sub.4PCy (103 mg, 0.228 mmol). Both solids were dissolved in CH.sub.2Cl.sub.2 (3 mL each) and the phosphine was added dropwise to [Rh(cod).sub.2][BAr.sup.F.sub.4] via cannula with vigorous stirring. The resulting light orange solution was allowed to stir for two hours at room temperature before the solvent was partially removed in vacuo (2 mL) and n-pentane (25 mL) was added. The resulting orange solid was filtered via cannula, washed with pentane (35 mL), and dried in vacuo to give [Rh(Cy.sub.2P(CH.sub.2).sub.4PCy.sub.2)(.sup.2:.sup.2-C.sub.8H.sub.12)][BAr.sup.F.sub.4] as an orange solid. Yield: 300 mg, 0.197 mmol, 86%.
Characterisation
[0402] .sup.1H solution NMR (400.1 MHz, CD.sub.2Cl.sub.2, 298K): 7.72 (br s, 8H, BAr.sup.F), 7.57 (s, 4H, BAr.sup.F), 5.02 (br s, 4 H, C.sub.8H.sub.12), 2.37-2.18 (m, 12H, C.sub.8H.sub.12+phosphine), 1.86-1.74 (m, 24 H, C.sub.8H.sub.12+phosphine), 1.56 (m, 4H, phosphine or C.sub.8H.sub.12), 1.37-1.28 (m, 20H, C.sub.8H.sub.12+phosphine). .sup.11B{.sup.1H} solution NMR (128.4 MHz, CD.sub.2Cl.sub.2, 298K): -6.5 (s). .sup.19F{.sup.1H} solution NMR (376.5 MHz, CD.sub.2Cl.sub.2, 298K): -62.9 (s). .sup.31P{.sup.1H} solution NMR (162.0 MHz, CD.sub.2Cl.sub.2, 298K): 12.5 (d, J.sub.RhP2=140 Hz). Elemental analysis found (calculated) for C.sub.68H.sub.76B.sub.1F.sub.24P.sub.2Rh.sub.1: C, 53.56 (53.49); H, 4.02 (4.91).
1.12Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.4.PCy.SUB.2.)(.SUP.2.:.SUP.2.-C.SUB.7.H.SUB.8.)][BAr.SUP.F..SUB.4.]
[0403] ##STR00044##
Synthesis
[0404] One Young's flask was charged with Rh(Cy.sub.2P(CH.sub.2).sub.4PCy.sub.2)(.sup.2:.sup.2-C.sub.8H.sub.12)][BAr.sup.F.sub.4] (220 mg, 0.144 mmol) and dissolved in 1,2-F.sub.2C.sub.6H.sub.4 (3 mL). The orange solution was freeze-pump-thaw degassed three times before H.sub.2 gas (1 bar) was added. The reaction mixture was allowed to stir for one hour before H.sub.2 and solvent were removed in vacuo. The remaining solid was washed with pentane (310 mL) and then dissolved in CH.sub.2Cl.sub.2 (3 mL). Addition of an excess of norbornadiene (0.22 mL, 2.166 mmol) and stirring for one hour resulted in the darkening of the solution. The solvent was partially removed under vacuum (2.0 mL) and the resulting solution was filtered via cannula into a Young's crystallization tube. Crystals of [Rh(Cy.sub.2P(CH.sub.2).sub.4PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4} were obtained by layering the resulting solution with n-pentane. Yield: 168 mg, 0.111 mmol, 77%.
Characterisation
[0405] .sup.1H solution NMR (400.1 MHz, CD.sub.2Cl.sub.2, 298K): 7.72 (m, 8 H, BAr.sup.F), 7.57 (s, 4H, BAr.sup.F), 4.91 (overlapped dt, 4H, J.sub.HH=2.5, 1.9 Hz, C.sub.7H.sub.8), 4.04 (br s, 2 H, C.sub.7H.sub.8), 2.15 (br s, 4H, C.sub.7H.sub.8), 1.94-1.68 (m, 30H, phosphine), 1.43-1.21 (m, 22H, phosphine). B{.sup.1H} solution NMR (128.4 MHz, CD.sub.2Cl.sub.2, 298K): -6.6 (s). .sup.19F{.sup.1H} solution NMR (376.5 MHz, CD.sub.2Cl.sub.2, 298K): 8 -62.9 (s). .sup.31P{.sup.1H} solution NMR (162.0 MHz, CD.sub.2Cl.sub.2, 298K): 26.8 (d, J.sub.RhP2=152 Hz). Elemental analysis found (calculated) for C.sub.67H.sub.72P.sub.2F.sub.24BRh: C, 53.33 (53.26); H, 4.81 (4.60).
1.13Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.4.PCy.SUB.2.)(.SUP.2.:.SUP.2.-C.SUB.7.H.SUB.12.)]]BAr.SUP.F..SUB.4.]
[0406] ##STR00045##
Synthesis
[0407] Addition of H.sub.2 gas (1 bar) to a crystalline samples of [Rh(Cy.sub.2P(CH.sub.2).sub.4PCY.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.8)][BAr.sup.F.sub.4] led to the quantitative formation of [Rh(Cy.sub.2P(CH.sub.2).sub.4PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4] after 5 minutes. The crystalline sample goes opaque and dark upon hydrogenation.
Characterisation
[0408] Single crystal X-ray raw data were collected at 150 K using an Agilent SuperNova diffractometer (Cu K radiation, =1.54180 ). Collected crystal lattice parameters: monoclinic (P2/n), a=19.00390(10), b=18.02740(10), c=20.06620(10), =92.2230(10), V=6869.33(6), Z=4.
1.14Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.4.PCy.SUB.2.)(.SUP.2.-propene)][BAr.SUP.F..SUB.4.]
[0409] ##STR00046##
Synthesis
[0410] Addition of propene gas (1 bar) to a crystalline samples of [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.8)][BAr.sup.F.sub.4] led to the quantitative formation of [Rh(Cy.sub.2P(CH.sub.2).sub.4PCy.sub.2)(.sup.2-Propene)][BAr.sup.F.sub.4] after eight hours. The crystalline sample becomes light orange.
Characterisation
[0411] Single crystal X-ray raw data were collected at 100 K using a Rigaku 007 HF (High Flux) diffractometer (Cu K radiation, =1.54180 ) equipped with a HyPix-600HE detector. Collected crystal lattice parameters: monoclinic (C2/c), a=18.773(5), b=16.951(2), c=19.809(3), =90.109(15), V=6303(2) .sup.3, Z=4.
1.15Synthesis and characterization of Cy.SUB.2.F(CH.SUB.2.).SUB.5.PCy.SUB.2
[0412] ##STR00047##
Synthesis
[0413] One Schlenk flask was charged with [Cy.sub.2PLi.(THF)](1 g, 3.62 mmol) and suspended in dry 1,4-dioxane (15 mL) at room temperature. Then, 1,5-dibromopentane (0.24 mL, 1.76 mmol) was added dropwise via syringe promptly producing a colourless solution. The solution was stirred at room temperature for two hours yielding a white suspension. The resulting suspension was filtered via cannula and 1,4-dioxane was removed in vacuo to give a colourless solid. This solid was dissolved in dry ethanol (15 mL) upon warming up. Cy.sub.2P(CH.sub.2).sub.5PCy.sub.2 was obtained as a colorless crystalline solid by storing the resulting solution at 4 C. for 24 h. Yield: 620 mg, 1.33 mmol, 76%.
Characterisation
[0414] .sup.1H solution NMR (400.1 MHz, C.sub.6D.sub.6, 298K): 1.89-1.50 (m, 30H), 1.42 (m, 4H, phosphine), 1.32-1.15 (m, 20H). .sup.31P{.sup.1H} solution NMR (162.0 MHz, C.sub.6D.sub.6, 298K): -5.8 (d, J.sub.RhP2=139 Hz). .sup.13C{.sup.1H} solution NMR (100.6 MHz, C.sub.6D.sub.6, 298K): 8 34.0 (d, J.sub.CP=15 Hz, CH), 30.9 (d, J.sub.CP=15 Hz), 29.5 (d, J.sub.CP=9 Hz), 28.8 (d, J.sub.Cp=21 Hz), 27.76 (d, J.sub.CP=17 Hz), 27.74 (br s), 27.0 (s), 21.9 (d, J.sub.CP=19 Hz).
1.16Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.5.PCy.SUB.2.)(.SUP.2.:.SUP.2.-C.SUB.8.H.SUB.12.)][BAr.SUP.F..SUB.4.]
[0415] ##STR00048##
Synthesis
[0416] One Schlenk flask was charged with [Rh(cod).sub.2][BAr.sup.F.sub.4] (500 mg, 0.423 mmol) and another filled with Cy.sub.2P(CH.sub.2).sub.5PCy (197 mg, 0.423 mmol). Both solids were dissolved in CH.sub.2Cl.sub.2 (5 mL each) and the phosphine was added dropwise to [Rh(cod).sub.2][BAr.sup.F.sub.4] via cannula with vigorous stirring. The resulting light orange solution was allowed to stir for two hours at room temperature before the solvent was partially removed in vacuo (4 mL) and n-pentane (25 mL) was added. The resulting orange solid was filtered via cannula, washed with pentane (310 mL), and dried in vacuo to give [Rh(Cy.sub.2P(CH.sub.2).sub.5PCy.sub.2)(.sup.2:.sup.2-C.sub.8H.sub.12)][BAr.sup.F.sub.4] as an orange solid.
Characterisation
[0417] .sup.1H solution NMR (400.1 MHz, CD.sub.2Cl.sub.2, 298K): 7.72 (br s, 8H, BAr.sup.F), 7.56 (s, 4H, BAr.sup.F), 4.90 (br s, 4H, C.sub.8H.sub.12), 2.37-1.52 (several m, 42H, C.sub.8H.sub.12+phosphine), 1.53-1.26 (m, 20H, C.sub.8H.sub.12+phosphine). B{.sup.1H} solution NMR (128.4 MHz, CD.sub.2Cl.sub.2, 298K): -6.5 (s). .sup.19F{.sup.1H} solution NMR (376.5 MHz, CD.sub.2Cl.sub.2, 298K): -62.9 (s). .sup.31P{.sup.1H} solution NMR (162.0 MHz, CD.sub.2Cl.sub.2, 298K): 8.3 (d, J.sub.RhP2=138 Hz).
1.17Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.8.PCy.SUB.2.)(.SUP.2.:.SUP.2.-C.SUB.7.H.SUB.8.)][BAr.SUP.F..SUB.4.]
[0418] ##STR00049##
Synthesis
[0419] One Young's flask was charged with [Rh(Cy.sub.2P(CH.sub.2).sub.8PCy.sub.2)(.sup.2:.sup.2-C.sub.8H.sub.12)][BAr.sup.F.sub.4] (160 mg, 0.104 mmol) and dissolved in 1,2-F.sub.2C.sub.8H.sub.4 (3 mL). The orange solution was freeze-pump-thaw degassed three times before H.sub.2 gas (1 bar) was added. The reaction mixture was allowed to stir vigorously for 5 mins and it was immediately freeze-pump-thaw degassed three times to remove H.sub.2. n-Pentane (25 mL) was then added to give a pale yellow suspension. The resulting solid was filtered via cannula, washed with pentane (310 mL), dried in vacuo and then dissolved in CH.sub.2Cl.sub.2 (3 mL). Addition of an excess of norbornadiene (0.15 mL, 1.47 mmol) and stirring for one hour gave a dark red solution. The solvent was partially removed under vacuum (1.5 mL) and the solution was filtered via cannula into a Young's crystallization tube. Crystals of [Rh(Cy.sub.2P(CH.sub.2).sub.5PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.8)][BAr.sup.F.sub.4] were obtained by layering the resulting solution with n-pentane. Yield: 140 mg, 0.091 mmol, 88%.
Characterisation
[0420] .sup.1H solution NMR (400.1 MHz, CD.sub.2Cl.sub.2, 298K): 7.71 (br s, 8H, BAr.sup.F), 7.56 (s, 4H, BAr.sup.F), 4.69 (br m, 4H, C.sub.7H.sub.8), 3.97 (br s, 2H, C.sub.7H.sub.8), 2.22 (m, 4H, C.sub.7H.sub.8), 1.91-1.68 (m, 34H, phosphine), 1.43-1.21 (m, 20H, phosphine). .sup.11B{.sup.1H} solution NMR (128.4 MHz, CD.sub.2Cl.sub.2, 298K): -6.6 (s). .sup.19F{.sup.1H} solution NMR (376.5 MHz, CD.sub.2Cl.sub.2, 298K): -62.9 (s). .sup.31P{.sup.1H} solution NMR (162.0 MHz, CD.sub.2Cl.sub.2, 298K): 18.7 (d, J.sub.RhP2=150 Hz).
1.18Synthesis and characterization of [Rh(Cy.SUB.2.P(CH.SUB.2.).SUB.8.PCy.SUB.2.)(.SUP.2.:.SUP.2.-C.SUB.7.H.SUB.12.)][BAr.SUP.F..SUB.4.]
[0421] ##STR00050##
Synthesis
[0422] Addition of H.sub.2 gas (1 bar) to a crystalline samples of [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.8)][BAr.sup.F.sub.4] led to the quantitative formation of a compound of formulae [Rh(Cy.sub.2P(CH.sub.2).sub.5PCY.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4] after 5 minutes. The crystalline sample turned yellow upon hydrogenation.
Characterisation
[0423] Single crystal X-ray raw data were collected at 100 K using an Agilent SuperNova diffractometer (Cu K radiation, =1.54180 ). Collected crystal lattice parameters: monoclinic (/2/a), a=20.6165(3), b=17.74689(19), c=77.1292(6), =94.5127(9), V=28132.4(5), Z=20.
1.19Synthesis and characterization of [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(NBD)][BAr.SUP.Cl..SUB.4.]
[0424] ##STR00051##
Synthesis
[0425] A stirred slurry of Na[BAr.sup.Cl.sub.4] (168 mg, 0.27 mmol) and NBD (0.25 mL) in CH.sub.2Cl.sub.2 (20 mL) was treated with a yellow solution of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Cl].sub.2 (153 mg, 0.136 mmol) in CH.sub.2Cl.sub.2 (10 mL). The resultant red mixture was stirred at ambient temperature for 4 h and then filtered. The filtrate was concentrated under vacuum (ca. 2 mL) and layered with pentane. Dark orange crystals suitable for an x-ray diffraction study were obtained. Yield: 273 mg (84%).
Characterisation
[0426] .sup.1H NMR (CD.sub.2Cl.sub.2, 400 MHz, 298 K): 7.04 (m, 8H, ortho-ArH), 7.01 (t, 4H, para-ArH), 5.53 (br s, 4H, alkene CH), 4.17 (br s, 2H, bridgehead CH), 2.00-1.98 (br d, 4H, overlapping aliphatic CH), 1.93-1.65 (m, 26H, overlapping aliphatic CH), 1.36-1.19 (m, overlapping 16H, aliphatic CH), 1.14-1.04 (m, 4H, overlapping aliphatic CH). .sup.31P{.sup.1H} NMR (CD.sub.2Cl.sub.2, 162 MHz): 69.9 (d, J.sub.RhP 154Hz). .sup.11B{.sup.1H} NMR (CD.sub.2Cl.sub.2, 128 MHz, 298 K): -6.9 (s). .sup.31P{.sup.1H} SSNMR (162 MHz, 10 kHz spin rate, 294 K): 64.7 (d, J.sub.RhP 145 Hz), 63.0 (d, J.sub.RhP 147 Hz). .sup.13C{.sup.1H} SSNMR (101 MHz, 10 kHz spin rate, 294 K): 165.3 (br, [BAr.sup.Cl.sub.4].sup.), 134.7 ([BAr.sup.Cl.sub.4].sup.), 131.1 (br, [BAr.sup.CL.sub.4].sup.), 122.5 ([BAr.sup.Cl.sub.4].sup.), 88.4 (CC), 87.4 (CC), 80.3 (CC), 79.4 (CC), 69.8 (bridge C), 55.1 (2C, bridgehead C), 34.2-18.9 (multiple aliphatic resonances). .sup.1H projection from .sup.1H/.sup.13C Frequency Switched Lee-Goldburg HETCOR SSNMR: 7.02 (br), 2.18 (br). ESI-MS found (calc.): m/z 617.29 (617.29). Elemental analysis found (calc. for C.sub.57H.sub.68BCl.sub.8P.sub.2Rh): C 56.31 (56.47), H 5.70 (5.65).
1.20Synthesis and characterization of [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(NBD)][BAr(F).SUB.4.]
[0427] ##STR00052##
Synthesis
[0428] A stirred slurry of Na[BAr.sup.F.sub.4] (91 mg, 0.19 mmol) and NBD (0.25 mL) in CH.sub.2Cl.sub.2 (20 mL) was treated with a yellow solution of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Cl].sub.2 (96 mg, 0.086 mmol) in CH.sub.2Cl.sub.2 (10 mL). The resultant red mixture was stirred at ambient temperature for 4 h and then filtered. The filtrate was concentrated under vacuum (ca. 1 mL) and layered with pentane. Dark orange crystals suitable for an x-ray diffraction study were obtained. Yield: 154 mg (83%).
Characterisation
[0429] .sup.1H NMR (CD.sub.2Cl.sub.2, 400 MHz, 298 K): 6.74 (m, 8H, ortho-ArH), 6.42 (br t, 4H para-ArH), 5.53 (br s, 4H, alkene CH), 4.17 (br s, 2H, bridgehead CH), 2.01-1.98 (br d, 4H, overlapping aliphatic CH), 1.93-1.67 (m, 26H, overlapping aliphatic CH), 1.37-1.19 (m, 16H, overlapping aliphatic CH), 1.14-1.04 (m, 4H, overlapping aliphatic CH). .sup.31 P{.sup.1H} NMR (CD.sub.2Cl.sub.2, 162 MHz, 298 K): 6 69.8 (d, J.sub.RhP 154 Hz). .sup.116{.sup.1H} NMR (CD.sub.2Cl.sub.2, 128 MHz, 298 K): -6.6 (s). .sup.19F{.sup.1H} NMR (CD.sub.2Cl.sub.2, 376 MHz, 298 K): -115.2 (s). .sup.31 P{.sup.1H} SSNMR (162 MHz, 10 kHz spin rate, 294 K): 70.9 (br s). .sup.13C{.sup.1H} SSNMR (101 MHz, 10 kHz spin rate, 294 K): 162.5 (m, [BAr.sup.F.sub.4].sup.), 116.8 ([BAr.sup.F.sub.4].sup.), 114.3 ([BAr.sup.F.sub.4].sup.), 97.7 ([BAr.sup.F.sub.4].sup.), 89.3 (CC), 79.6 (C=C), 71.4 (bridge C), 54.4 (bridgehead C), 34.5-20.7 (multiple aliphatic resonances). .sup.1H projection from .sup.1H/.sup.13C Frequency Switched Lee-Goldburg HETCOR SSNMR: 6.42 (br), 2.65 (br). ESI-MS found (calc.): m/z 617.29 (617.29). Elemental analysis found (calc. for C.sub.57H.sub.68BF.sub.8P.sub.2Rh): C 3.26 (63.34), H 6.42 (6.34).
1.21Synthesis and characterization of [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(NBD)][BAr.SUP.H..SUB.4.] (comparator)
[0430] ##STR00053##
Synthesis
[0431] A stirred slurry of Na[BAr.sup.H.sub.4] (55 mg, 0.16 mmol) and NBD (0.25 mL) in CH.sub.2Cl.sub.2 (20 mL) was treated with a yellow solution of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Cl].sub.2 (90 mg, 0.080 mmol) in CH.sub.2Cl.sub.2 (10 mL). The resultant red mixture was stirred at ambient temperature for 4 h and then filtered. The filtrate was concentrated under vacuum (ca. 1 mL) and layered with pentane. Dark orange crystals suitable for an x-ray diffraction study were obtained. Yield: 117 mg (78%).
Characterisation
[0432] .sup.1H NMR (CD.sub.2Cl.sub.2, 400 MHz, 298 K): 7.32 (br m, 8H, ortho-ArH), 7.04 (br t, J.sub.HH 7.5 Hz, 8H, meta-ArH), 6.89 (br t, J.sub.HH 7.5 Hz, 4H, para-ArH), 5.52 (br s, 4H, alkene CH), 4.16 (s, 2H, bridgehead CH), 1.99 (br d, J.sub.HH 12.3 Hz, 4H, overlapping aliphatic CH), 1.92-1.61 (m, 26H, overlapping aliphatic CH), 1.38-1.20 (m, 16H, overlapping aliphatic CH), 1.14-1.01 (m, 4H, overlapping aliphatic CH). .sup.31P{.sup.1H} NMR (CD.sub.2Cl.sub.2, 162 MHz, 298 K): 69.8 (d, .sub.JRhP 154 Hz). .sup.11B{.sup.1H} NMR (CD.sub.2Cl.sub.2, 128 MHz, 298 K): -6.6 (s). .sup.31 P{.sup.1H} SSNMR (162 MHz, 10 kHz spin rate, 293 K): 75.8 (d, J.sub.RhP 134 Hz), 64.8 (d, J.sub.RhP 132 Hz). .sup.13C{.sup.1H} SSNMR (101 MHz, 10 kHz spin rate, 293 K): 165.2-158.5 (m, [BAr.sup.H.sub.4].sup.), 136.2-135.1 (m, [BAr.sup.E1.sub.4].sup.), 125.6-120.7 (m, [BAr.sup.H.sub.4]), 89.3 (CC), 85.4 (CC), 83.8 (CC), 81.8 (CC), 70.6 (bridge C), 54.5 (2C, bridgehead C), 35.8-15.8 (multiple aliphatic resonances). .sup.1H projection from .sup.1H/.sup.13C Frequency Switched Lee-Goldburg HETCOR SSNMR: 6.98 (br), 2.00 (br). ESI-MS found (calc.): m/z 617.29 (617.29). Elemental analysis found (calc. for C.sub.57H.sub.76BP.sub.2Rh): C 73.13 (73.07), H 8.08 (8.18).
1.22Synthesis and characterization of [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(NBD)[A{OC(CF.SUB.3.).SUB.3.}.SUB.4.]
[0433] ##STR00054##
Synthesis
[0434] A solution of [Rh(NBD).sub.2][Al{OC(CF.sub.3).sub.3}.sub.4] (123 mg, 0.10 mmol) in CH.sub.2Cl.sub.2 (40 mL) was treated dropwise with a solution of dcpe (42 mg, 0.99 mmol) in CH.sub.2Cl.sub.2 (20 mL) at 60 C. Upon complete addition the color of the reaction solution changed from burgundy to orange. After 2 h, the solution was allowed to warm to ambient temperature. The solvent was then removed under vacuum and the resultant red residue was washed with pentane (310 mL). Extraction into CH.sub.2Cl.sub.2 (2 mL) followed by layering with pentane afforded large red crystals suitable for an x-ray diffraction study. Yield: 127 mg (80%).
Characterisation
[0435] .sup.1H NMR (CD.sub.2Cl.sub.2, 400 MHz, 298 K): 5.54 (br s, 4H, alkene CH), 4.20 (br s, 2H, bridgehead CH), 2.02-1.98 (br d, 4H, overlapping aliphatic CH), 1.93-1.61 (m, 26H, overlapping aliphatic CH), 1.36-1.21 (m, overlapping 16H, aliphatic CH), 1.14-1.04 (m, 4H, overlapping aliphatic CH). .sup.31P{.sup.1H} NMR (CD.sub.2Cl.sub.2, 202 MHz): 69.8 (d, J.sub.RhP 154Hz). .sup.27Al NMR (CD.sub.2Cl.sub.2, 104 MHz, 298 K): 34.6 (s). .sup.31P{.sup.1H} SSNMR (162 MHz, 10 kHz spin rate, 294 K): 70.2 (d, J.sub.RhP 155 Hz), 69.0 (d, J.sub.RhP 156 Hz). .sup.13C{.sup.1H} SSNMR (101 MHz, 10 kHz spin rate, 294 K):121.6 (br q, J.sub.CF 280 Hz, CF.sub.3), 94.1 (CC, 2C), 84.7 (CC), 82.5 (d, CC), 79.5 (AIDC), 72.0 (bridge C), 56.5 (bridgehead C), 56.0 (bridgehead C), 38.7-22.3 (multiple aliphatic resonances). .sup.27Al SSNMR (104 MHz, 15 kHz spin rate, 294 K): 33.7. .sup.1H projection from .sup.1H/.sup.13C Frequency Switched Lee-Goldburg HETCOR SSNMR: 6.00 (br), 4.51 (br), 1.97 (br). ESI-MS found (calc.): m/z 617.29 (617.29). Elemental analysis found (calc. for C.sub.43H.sub.56AlF.sub.36O.sub.4P.sub.2Rh): C 37.08 (37.14), H 3.47 (3.56).
1.23Synthesis and characterization of [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(NBA)][BAr.SUP.Cl..SUB.4.]
[0436] ##STR00055##
Synthesis
[0437] Hydrogenation (1 atm) of a crystalline sample of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)(NBD)][BAr.sup.Cl.sub.4] led to the formation of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)(NBA)][BAr.sup.Cl.sub.4] in 1 h.
Characterisation
[0438] .sup.31P{.sup.1H} SSNMR (162 MHz, 10 kHz spin rate, 158 K): 101.5 (br), 94.7 (br). .sup.13C{.sup.1H} SSNMR (101 MHz, 10 kHz spin rate, 158 K): 163.7 (br, [BAr.sup.Cl.sub.4].sup.), 131.5 (br, [BAr.sup.Cl.sub.4].sup.), 121.9 ([BAr.sup.Cl.sub.4].sup.), 37.0-14.6 (multiple aliphatic resonances). .sup.1H projection from .sup.1H/.sup.13C Frequency Switched Lee-Goldburg HETCOR SSNMR: 7.05 (br), 2.29 (br), 1.76 (br).
1.24Synthesis and characterization of [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(NBA)][BAr(F).SUB.4.].
[0439] ##STR00056##
Synthesis
[0440] Hydrogenation (1 atm) of a crystalline sample of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)(NBD)][BAr.sup.F.sub.4] led to the formation of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)(NBA)][BAr.sup.F.sub.4] in 3 h.
Characterisation
[0441] .sup.31P{.sup.1H} SSNMR (162 MHz, 10 kHz spin rate, 158 K): 103.6 (br). .sup.13C{.sup.1H} SSNMR (101 MHz, 10 kHz spin rate, 158 K): 165.5-159.7 (br m, [BAr.sup.F.sub.4].sup.), 116.2 ([BAr.sup.F.sub.4].sup.), 114.1 ([BAr.sup.F.sub.4].sup.), 97.4 ([BAr.sup.F.sub.4].sup.), 35.1-20.2 (multiple aliphatic resonances). .sup.1H projection from .sup.1H/.sup.13C Frequency Switched Lee-Goldburg HETCOR SSNMR: 6.45 (br), 2.64 (br), 1.62 (br).
1.24Synthesis and characterization of [Rh(Cy.SUB.2.PCH.SUB.2.CH.SUB.2.PCy.SUB.2.)(H).SUB.2.][Al{OC(CF.SUB.3.).SUB.3.}.SUB.4.]
[0442] ##STR00057##
Synthesis
[0443] Hydrogenation (1 atm) of a crystalline sample of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)(NBD)] [Al{OC(CF.sub.3).sub.3}.sub.4] led to the formation of [Rh(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)(H).sub.2][Al{0C(CF.sub.3).sub.3}.sub.4] in 1 h.
Characterisation
[0444] .sup.31P{.sup.1H} SSNMR (162 MHz, 10 kHz spin rate, 294 K): 99.5 (br). .sup.13C{.sup.1H} SSNMR (101 MHz, 10 kHz spin rate, 294 K): 121.6 (br q, J.sub.CF 280 Hz, CF.sub.3), 79.3 (AIDC), 38.2-19.9 (multiple aliphatic resonances). .sup.27Al SSNMR (104 MHz, 15 kHz spin rate, 294 K): 32.7. .sup.1H projection from .sup.1H/.sup.13C Frequency Switched Lee-Goldburg HETCOR SSNMR: 2.00 (br). Elemental analysis found (calc. for C.sub.42H.sub.50AlF.sub.36O.sub.4P.sub.2Rh): C 33.73 (33.75), H 3.19 (3.37).
Example 2
Alkene Isomerisation Catalytic Studies
2.1Alkene isomerisation with 1-butene
[0445] The complexes [1-NBA][BAr.sup.F.sub.4], [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct, [1-(ethene).sub.2][BAr.sup.F.sub.4]-Hex have been screened (but conditions not optimised) in the isomerization of 1-butene to 2-butene in solid/gas catalysis, acting SMOM-cat. This was performed on a small, but convenient, scale by taking a thick-walled NMR tube of volume ca. 1.9 cm.sup.3 fitted with Teflon stopcock that allows for the addition of gases, adding a crystalline sample of catalyst (3 mg, 2 gmoles), brief evacuation, refilling with 1-butene gas (15 psi, 79 gmoles.sup.78) and analysis by gas-phase .sup.1H NMR spectroscopy. This loading, assuming all sites in the crystalline material have the same activity, gives TON.sub.(bulk) of 42 for 100% conversion. This represents a minimum TON, as if only the most accessible sites, or those nearest to the surface, were kinetically competent then the actual number of active sites would be lower. To probe the influence of surface area for [1-NBA][BAr.sup.F.sub.4], large (edge length ca. 1-2 mm) crystals and finely crushed samples were prepared for which the surface area would be significantly greater. For both polymorphs of [1-(ethene).sub.2][BAr.sup.F.sub.4] crushed samples were used as large crystals could not be grown (
[1-NBA](BAr.SUP.F..SUB.4.] (big crystals)
[0446] [1-NBA][BAr.sup.F.sub.4] (big crystals) was used to catalyse the conversion of but-1-ene to but-2-ene. Conditions used: 2.5 mg catalyst loading, 15 psi but-1-ene, NMR tube volume 1.9 ml. The results are presented in Table 1.
TABLE-US-00001 TABLE 1 Data for the catalytic isomerisation of but-1-ene to but- 2-ene by crystals of [1-NBA][BAr.sub.4.sup.F] (big crystals). The conversion was measured by comparing the integrals of but-1-ene and but-2-ene in the gas phase NMR. The TON and TOF presented are the minimum possible, assuming all catalytic sites throughout the bulk to be catalytically active. Time (mins) Time (hr) % but-2-ene 0 0.000 0 2 0.033 55 5 0.083 70 10 0.167 79 15 0.250 84 20 0.333 87 25 0.417 88 30 0.500 88 35 0.583 89 40 0.667 91 45 0.750 91 50 0.833 91 55 0.917 91 60 1.000 93 100 1.667 93
[1NBA](BAr.SUP.F..SUB.4.] (crushed crystals)
[0447] [1NBA][BAr.sup.F.sub.4] (crushed crystals) was used to catalyse the conversion of but-1-ene to but-2-ene. Conditions used: 2.0 mg catalyst loading, 15 psi but-1-ene, NMR tube volume 1.9 ml. The results are presented in Table 2.
TABLE-US-00002 TABLE 2 Data for the catalytic isomerisation of but-1-ene to but-2-ene by crystals of [1-NBA][BAr.sub.4.sup.F] (crushed crystals). The conversion was measured by comparing the integrals of but-1-ene and but-2-ene in the gas phase NMR. The TON and TOF presented are the minimum possible, assuming all catalytic sites throughout the bulk to be catalytically active. This dataset is from the initial scoping of catalysis where the sample was left for 100 mins with no reloading. Time (mins) Time (hr) % but-2-ene 0 0.0000 0 1 0.0167 55 5 0.0833 84 10 0.1667 92 15 0.2500 95 20 0.3333 94 25 0.4167 95 30 0.5000 93 45 0.7500 93
[1-(ethene).SUB.2.](BAr.SUP.F..SUB.4.]-Oct (crushed crystals)
[0448] [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct was used to catalyse the conversion of but-1-ene to but-2-ene. Conditions used: 2.6 mg catalyst loading, 15 psi but-1-ene, NMR tube volume 1.8 ml. The results are presented in Table 3.
TABLE-US-00003 TABLE 3 Data for the catalytic isomerisation of but-1-ene to but- 2-ene by [1-(ethene).sub.2][BAr.sub.4.sup.F]-oct. This dataset is from the initial scoping of catalysis where the sample was left for 30 mins with no reloading. Conditions used: 2.6 mg catalyst loading, 15 psi but-1-ene, NMR tube volume 1.8 ml. Time (mins) Time (hr) % but-2-ene 0 0.000 0 1 0.017 63 3 0.050 79 5 0.083 85 7 0.117 88 9 0.150 89 10 0.167 92 15 0.250 94 20 0.333 95 25 0.417 96 30 0.500 95
[1-(ethene).SUB.2.](BAr.SUP.F..SUB.4.]-Hex (crushed crystals)
[0449] [1-(ethene).sub.2][BAr.sup.F.sub.4]-Hex was used to catalyse the conversion of but-1-ene to but-2-ene. Conditions used: 6.0 mg catalyst loading, 15 psi but-1-ene, NMR tube volume 1.9 ml. The results are presented in Table 4.
TABLE-US-00004 TABLE 4 Data for the catalytic isomerisation of but-1-ene to but-2-ene by [1- (ethene).sub.2][BAr.sub.4.sup.F]-hex. Due to the high catalytic loading isomerisation had reached equilibrium by the first data point. Conditions used: 6.0 mg catalyst loading, 15 psi but-1-ene, NMR tube volume 1.9 ml. Time (min) Time (hr) % but-2-ene 0 0.000 0 1 0.017 91 5 0.083 91 10 0.167 91
Discussion
[0450]
[0451]
2.2. Recyclability Studies
[1-NBA](BAr.SUP.F..SUB.4.] (big crystals)
[0452] The recyclability of [1-NBA][BAr.sup.F.sub.4] (big crystals) in the conversion of but-1-ene to but-2-ene was assessed. Conditions used: 2.6 mg catalyst loading, 15 psi but-1-ene, 1.8 ml NMR tube volume. The results are presented in Table 5.
TABLE-US-00005 TABLE 5 Data for the catalytic isomerisation of but-1-ene to but-2-ene by a sample of [1-NBA][BAr.sub.4.sup.F]-large. This dataset is from the recyclability experiment - over three reloadings no significant drop-offs in activity is observed. Conditions used: 2.6 mg catalyst loading, 15 psi but-1-ene, NMR tube volume 1.8 ml. Cumulative Time (mins) Time (hr) % but-2-ene conversion 0 0.000 0 0 1 0.017 27 27 3 0.050 39 39 5 0.083 47 47 8 0.133 57 57 10 0.167 65 65 15 0.250 71 71 20 0.333 76 76 25 0.417 78 78 30 0.500 80 80 35 0.583 80 80 40 0.667 83 83 45 0.750 84 84 46 0.767 45 129 48 0.800 53 137 50 0.833 61 145 52 0.867 65 149 55 0.917 73 157 60 1.000 78 162 65 1.083 78 162 70 1.167 82 166 80 1.333 87 171 85 1.417 85 169 90 1.500 87 171 91 1.517 29 200 93 1.550 44 215 95 1.583 52 223 97 1.617 62 233 99 1.650 64 235 100 1.667 66 237 105 1.750 73 244 110 1.833 78 249 115 1.917 77 248 120 2.000 78 249 125 2.083 82 253 130 2.167 82 253 135 2.250 83 254 200 3.333 87 258
[1-NBA](BAr.SUP.F..SUB.4.] (crushed crystals)
[0453] The recyclability of [1-NBA][BAr.sup.F.sub.4] (crushed crystals) in the conversion of but-1-ene to but-2-ene was assessed. Conditions used: 3.4 mg catalyst loading, 15 psi but-1-ene, 1.8 ml NMR tube. The results are presented in Table 6.
TABLE-US-00006 TABLE 6 Data for the catalytic isomerisation of but-1-ene to but-2-ene by a sample of [1-NBA][BAr.sub.4.sup.F]-crushed. This dataset is from the recyclability experiment - over three reloadings no significant drop-offs in activity is observed. Conditions used: 3.4 mg catalyst loading, 15 psi but-1-ene, NMR tube volume 1.8 ml. Cumulative Time (min) Time (hr) % but-2-ene conversion 0 0.000 0 0 1 0.017 20 20 3 0.050 30 30 5 0.083 47 47 7 0.117 66 66 10 0.167 76 76 15 0.250 86 86 20 0.333 88 88 25 0.417 91 91 30 0.500 93 93 31 0.517 12 105 33 0.550 30 123 35 0.583 44 137 37 0.617 56 149 39 0.650 65 158 40 0.667 68 161 45 0.750 78 171 50 0.833 83 176 55 0.917 86 179 60 1.000 90 183 65 1.083 92 185 70 1.167 94 187 71 1.183 15 202 73 1.217 30 217 75 1.250 42 229 77 1.283 55 242 79 1.317 62 249 80 1.333 66 253 85 1.417 71 258 90 1.500 81 268 95 1.583 85 272 100 1.667 87 274 105 1.750 92 279 110 1.833 94 281
[1-(ethene).SUB.2.][BAr.SUP.F..SUB.4.]-Oct (crushed crystals)
[0454] The recyclability of [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct (crushed crystals) in the conversion of but-1-ene to but-2-ene was assessed. Conditions used: 2.6 mg cat. Loading, 15 psi but-1-ene, 1.8 ml NMR tube. The results are presented in Table 7.
TABLE-US-00007 TABLE 7 Data for the catalytic isomerisation of but-1-ene to but-2-ene by a sample of [1-(ethene).sub.2][BAr.sub.4.sup.F]-oct. This dataset is from the recyclability experiment - over three reloadings no significant drop-offs in activity is observed. Conditions used: 2.6 mg catalyst loading, 15 psi but-1-ene, NMR tube volume 1.8 ml Cumulative Time (min) Time (hr) % but-2-ene conversion 0 0 0 0 1 0.017 63 63 3 0.050 79 79 5 0.083 85 85 7 0.117 88 88 9 0.150 89 89 10 0.167 92 92 15 0.250 94 94 20 0.333 95 95 25 0.417 96 96 30 0.500 95 95 31 0.517 39 134 33 0.550 53 148 35 0.583 62 157 37 0.617 66 161 39 0.650 69 164 40 0.667 72 167 45 0.750 77 172 50 0.833 81 176 55 0.917 86 181 60 1.000 85 180 65 1.083 86 181 70 1.167 89 184 75 1.250 88 183 76 1.267 32 215 78 1.300 45 228 80 1.333 53 236 82 1.367 59 242 84 1.400 64 247 85 1.417 66 249 90 1.500 70 253 95 1.583 75 258 100 1.667 77 260 105 1.750 79 262 110 1.833 83 266 115 1.917 85 268 120 2.000 88 271 150 2.500 97 280
[1-(ethene).SUB.2.](BAr.SUP.F..SUB.4.]-Hex (crushed crystals)
[0455] The recyclability of [1(ethene).sub.2][BAr.sup.F.sub.4]-Hex (crushed crystals) in the conversion of but-1-ene to but-2-ene was assessed. Conditions used: 6.0 mg cat. Loading, 15 psi but-1-ene, 1.9 ml NMR tube. The results are presented in Table 7.
TABLE-US-00008 TABLE 8 Data for the catalytic isomerisation of but-1-ene to but-2-ene by a sample of [1-(ethene).sub.2][BAr.sub.4.sup.F]-oct. This dataset is from the recyclability experiment - over three reloadings no significant drop-offs in activity is observed. Conditions used: 6.0 mg catalyst loading, 15 psi but-1-ene, NMR tube volume 1.9 ml. Cumulative Time Time (hr) % but-2-ene conversion 0 0.000 0 0 1 0.017 91 91 5 0.083 91 91 10 0.167 91 91 15 0.250 89 180 20 0.333 91 182 21 0.350 91 182 22 0.367 59 241 26 0.433 89 271 32 0.533 92 274
Discussion
[0456] The four catalyst systems ([1-NBA][BAr.sup.F.sub.4] (big crystals), [1-NBA][BAr.sup.F.sub.4] (crushed crystals), [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct (crushed crystals) and [1-(ethene).sub.2][BAr.sup.F.sub.4]-Hex (crushed crystals)) can all be recycled, and
[0457] In contrast to the exemplary catalysts, comparator catalysts containing isobutyl ligands instead of cyclohexyl ligands ([(Bu.sub.2PCH.sub.2CH.sub.2P.sup.iBu.sub.2)Rh(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4] [.sup.iBu-NBA] and [(.sup.lPu.sub.2PCH.sub.2CH.sub.2PBu.sub.2)Rh(.sup.2-C.sub.2H.sub.4).sub.2HBAr.sup.F.sub.4] [.sup.iBu-(ethene).sub.2]) demonstrated no recyclability.
2.3Passivation Studies
[0458] Samples of [1-NBA][BAr.sup.F.sub.4] (big crystals) and [1-NBA][BAr.sup.F.sub.4] (crushed crystals) were exposed to CO (2 bar) for 150 seconds. Solution .sup.31P{.sup.1H} NMR showed the sample had gone to 70% completion. [(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Rh(CO).sub.2][BAr.sup.F.sub.4] is inactive in the catalytic isomerisation of butane. The surface of the crystals (both big and crushed) would react faster than the bulk, effectively turning off the surface for catalysisthe intention being investigating whether this is a surface process or bulk process. However with [1-NBA][BAr.sup.F.sub.4] (big crystals) it was noted that significant fracturing of the crystals occurred during the exposure to CO (and presumably the same would be happening on [1-NBA][BAr.sup.F.sub.4] (crushed crystals), but not be observable by the naked eye).
[0459] Similar studies were carried out with [1-(ethene).sub.2][BAr.sup.F.sub.4]Oct and [1-(ethene).sub.2][BAr.sup.F.sub.4]-Hex, however due to the small amount of sample of both available quantification of the extent of passivation by .sup.31 P{.sup.1H} NMR was not possible. The same conditions were used (150 seconds of CO at 2 bar).
CO-passivated [1-NBA](BAr.SUP.F..SUB.4.] (big crystals)
[0460] CO-passivated [1-NBA][BAr.sup.F.sub.4] (big crystals) was used to catalyse the conversion of but-1-ene to but-2-ene. Conditions used: 2.8 mg cat. Loading, 15 psi but-1-ene, 1.9 ml NMR tube volume. The results are presented in Table 9.
TABLE-US-00009 TABLE 9 Data for the catalytic isomerisation of but-1-ene to but-2-ene by a sample of [1-NBA][BAr.sub.4.sup.F]-big after CO passivation min. TOF Time (mins) Time (hr) % but-2-ene min. TON (hr.sup.1) 0 0.000 0 0.0 0.0 1 0.017 33 13.9 831.3 3 0.050 47 19.7 394.7 5 0.083 57 23.9 287.2 7 0.117 61 25.6 219.5 9 0.150 66 27.7 184.7 10 0.167 67 28.1 168.8 15 0.250 71 29.8 119.2 20 0.333 74 31.1 93.2 25 0.417 76 31.9 76.6 30 0.500 78 32.7 65.5 35 0.583 79 33.2 56.9 40 0.667 79 33.2 49.8 45 0.750 80 33.6 44.8 50 0.833 81 34.0 40.8 55 0.917 82 34.4 37.6 60 1.000 82 34.4 34.4
[0461]
CO-passivated [1-NBA](BAr.SUP.F..SUB.4.] (crushed crystals)
[0462] CO-passivated [1-NBA][BAr.sup.F.sub.4] (crushed crystals) was used to catalyse the conversion of but-1-ene to but-2-ene. Conditions used: 2.6 mg cat. Loading, 15 psi but-1-ene, 1.8 ml NMR tube volume. The results are presented in Table 10.
TABLE-US-00010 TABLE 10 Data for the catalytic isomerisation of but-1-ene to but-2-ene by a sample of [1-NBA][BAr.sub.4.sup.F]-crushed after CO passivation min. TOF Time (mins) Time (hr) % but-2-ene min. TON (hr.sup.1) 0 0.000 0 0.0 0.0 1 0.017 23 9.9 591.9 3 0.050 46 19.7 394.6 5 0.083 57 24.4 293.4 7 0.117 65 27.9 239.0 9 0.150 69 29.6 197.3 10 0.167 70 30.0 180.2 15 0.250 73 31.3 125.3 20 0.333 76 32.6 97.8 25 0.417 76 32.6 78.2 30 0.500 78 33.5 66.9 35 0.583 79 33.9 58.1 40 0.667 82 35.2 52.8 45 0.750 81 34.7 46.3
[0463]
Discussion
[0464] It has been shown that addition of CO.sub.(g) to crystalline samples of [Rh(Bu.sub.2PCH.sub.2CH.sub.2PBu.sub.2)(.sup.2,.sup.2-C.sub.4H.sub.6)][BAr.sup.F.sub.4] is slow enough (days) to form a catalytically inactive, passivated, layer of [Rh(Bu.sub.2PCH.sub.2CH.sub.2PBu.sub.2)(CO).sub.2][BAr.sup.F.sub.4] in the resulting crystalline material..sup.42 This allows for the activity of surface sites to be probed in catalysis, which were suggested to be considerably more active compared to the bulk. This approach was inspired by the work of Brookhart on single-crystal solid/gas catalysis using [PCP.sup.iPr=.sup.3-C.sub.6H.sub.3-2,6-(OP(C.sub.6H.sub.2-2,4,6-(CF.sub.3).sub.3).sub.2].sup.43 For the complexes reported here reaction with CO is much faster, i.e. large crystals of [1-NBA][BAr.sup.F.sub.4] react in 2 minutes to form [(Cy.sub.2PCH.sub.2CH.sub.2PCy.sub.2)Rh(CO).sub.2][BAr.sup.F.sub.4] in 70% conversion. At the same time considerable cracking of the crystals also occurred, that likely exposes the interior of the crystals. This means that passivation of just the surface sites is problematic and has therefore not been pursued further with these samples. However, that [1-NBA][BAr.sup.F.sub.4]-large shows a significantly lower TOF (based on the bulk) compared to more finelydivided [1-NBA][BAr.sup.F.sub.4]-crushed and [1-(ethene).sub.2][BAr.sup.F.sub.4]-Oct suggests that surface effects are import here, and the most active catalyst sites sit at, or near, the surface. This hypothesis is further strengthened by the larger TOF for porous [1-(ethene).sub.2][BAr.sup.F.sub.4]-Hex in which a significant proportion, if not all, of the metal sites are potentially active; pointing as they do into the large cylindrical pores of the single-crystal.
2.4. Overview of Catalytic Characteristics
[0465]
[0466] In summary, it is believed that catalysts such as [1-(ethene).sub.2][BAr.sup.F.sub.4]-Hex are the first well-defined molecular systems that operate at 298 K under, industrially appealing, solid/gas conditions. In addition, they offer fine control of the spatial environment in the solid-state (i.e. show structure/activity relationships), show TOF.sub.(min) that are competitive with the fast homogenous systems, and, moreover are recyclable.
Example 3
Further Alkene Isomerisation Catalytic Studies
3.1Alkene isomerisation with 1-butene
[0467] The ability of compounds [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.4PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.5PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2-Propene)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.H.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr(F).sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.H.sub.4] (comparator, prepared in situ) and [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(H).sub.2][Al{OC(CF.sub.3).sub.3}.sub.4] to catalyse the isomerisation of 1-butene to 2-butene was assessed. The results are presented in Tables 11-18 below:
TABLE-US-00011 TABLE 11 Phosphine effects in catalysis. Data for the catalytic isomerization of but-1-ene to but-2-ene by crystals of [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sub.4.sup.F]. The conversion was measured by gas phase .sup.1H NMR spectroscopy comparing the integrals corresponding to 1-butene and 2-butene. Time (mins) Time (hr) % 2-butene 2.35 0.039 6 10 0.167 23 20 0.333 44 30 0.500 58 40 0.667 66 50 0.833 71 60 1.00 75 70 1.167 77 80 1.333 79 90 1.500 80 100 1.667 81 207 3.450 90
TABLE-US-00012 TABLE 12 Phosphine effects in catalysis. Data for the catalytic isomerization of but-1-ene to but-2-ene by crystals of [Rh(Cy.sub.2P(CH.sub.2).sub.4PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sub.4.sup.F]. The conversion was measured by gas phase .sup.1H NMR spectroscopy comparing the integrals corresponding to 1-butene and 2-butene Time (mins) Time (hr) % 2-butene 1.65 0.028 6 10 0.167 32 20 0.333 45 30 0.500 54 40 0.667 60 50 0.833 65 60 1.00 68 70 1.167 71 80 1.333 73 90 1.500 74 100 1.667 76 290 4.833 90
TABLE-US-00013 TABLE 13 Phosphine effects in catalysis. Data for the catalytic isomerization of but-1-ene to but-2-ene by crystals of [Rh(Cy.sub.2P(CH.sub.2).sub.5PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sub.4.sup.F]. The conversion was measured by gas phase .sup.1H NMR spectroscopy comparing the integrals corresponding to 1-butene and 2-butene. Time (mins) Time (hr) % 2-butene 1.65 0.028 18 10 0.167 53 20 0.333 64 30 0.500 69 40 0.667 73 50 0.833 75 60 1.00 76 70 1.167 78 80 1.333 80 90 1.500 81 100 1.667 82 205 3.417 90
TABLE-US-00014 TABLE 14 Phosphine effects in catalysis. Data for the catalytic isomerization of but-1-ene to but-2-ene by crystals of [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2-propene)][BAr.sub.4.sup.F]. The conversion was measured by gas phase .sup.1H NMR spectroscopy comparing the integrals corresponding to 1-butene and 2-butene Time (mins) Time (hr) % 2-butene 1.6 0.027 4 13.3 0.221 18 27.8 0.463 27 36.1 0.602 31 57.9 0.965 40 95.3 1.588 50 161.7 2.695 61 241.5 4.025 71 315.0 5.25 77 603.0 10.05 90
TABLE-US-00015 TABLE 15 Anion effects in catalysis. Data for the catalytic isomerization of but-1-ene to but-2-ene by crushed [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sub.4.sup.Cl]. The conversion was measured by gas phase .sup.1H NMR spectroscopy comparing the integrals corresponding to 1-butene and 2-butene Time (mins) Time (hr) % 2-butene 2.16 0.036 72 3.25 0.054 79 3.96 0.066 82 5.30 0.088 86 7.38 0.123 89 8.41 0.140 91 10.46 0.174 93 15.6 0.260 95 22 0.367 96
TABLE-US-00016 TABLE 16 Anion effects in catalysis. Data for the catalytic isomerization of but-1-ene to but-2-ene by crushed [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr(F).sub.4]. The conversion was measured by gas phase .sup.1H NMR spectroscopy comparing the integrals corresponding to 1-butene and 2-butene. Time (mins) Time (hr) % 2-butene 1.6 0.028 35 4.6 0.077 76 6.7 0.113 85 8.2 0.137 90 10.3 0.172 93 12.5 0.208 95 14.9 0.250 96 25.5 0.425 97 31.8 0.530 97
TABLE-US-00017 TABLE 17 Anion effects in catalysis. Data for the catalytic isomerization of but-1-ene to but-2-ene by crushed [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sub.4.sup.H] (comparator) as prepared in situ. The conversion was measured by gas phase .sup.1H NMR spectroscopy comparing the integrals corresponding to 1-butene and 2-butene Time (mins) Time (hr) % 2-butene 1.25 0.021 0 1.96 0.033 0.5 2.78 0.046 1 3.48 0.058 1.2 4.20 0.070 1.4 4.93 0.082 1.5 5.63 0.094 1.7 6.35 0.105 1.8 726.35 12.21 10.5
TABLE-US-00018 TABLE 18 Anion effects in catalysis. Data for the catalytic isomerization of but-1-ene to but-2-ene by crushed [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(H).sub.2][Al{OC(CF.sub.3).sub.3}.sub.4]. The conversion was measured by gas phase .sup.1H NMR spectroscopy comparing the integrals corresponding to 1-butene and 2-butene. Time (mins) Time (hr) % 2-butene 0.92 0.015 0 2.40 0.040 71 4.18 0.070 84 5.65 0.094 89 7.33 0.122 91 8.70 0.145 92 10.16 0.169 93 11.70 0.195 93
[0468] The data presented in Tables 11-18 show that compounds [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.4PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.5PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2-propene)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2- C.sub.7H.sub.12)][BAr.sup.Cl.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr(F).sub.4] and [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(H).sub.2][Al{OC(CF.sub.3).sub.3}.sub.4] are effective catalysts in the conversion of 1-butene to 2-butene.
3.2 Phosphine effects in 1-butene isomerisation
[0469] The ability of compounds [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.5PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.4PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4] and [Rh(Cy.sub.2P(CH.sub.2).sub.3PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4] to catalyse the isomerisation of 1-butene to 2-butene was assessed. The results are presented in
3.3 Anion effects in 1-butene isomerisation
[0470] The ability of compounds [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(H).sub.2][Al{OC(CF.sub.3).sub.3}.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4], [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr(F).sub.4] and [Rh(Cy.sub.2P(CH.sub.2).sub.2PCy.sub.2)(.sup.2:.sup.2-C.sub.7H.sub.12)][BAr.sup.F.sub.4] (comparator, prepared in situ) to catalyse the isomerisation of 1-butene to 2-butene was assessed. The results are presented in
3.4 Scale-up 1-butene isomerisation catalytic studies
[0471] Scale-up experiments were performed by loading crystalline samples of each catalyst (1.0-2.5 mg, ca. 0.7-1.7 mol) into a high-pressure reactor of volume 61 mL fitted with Teflon stopcocks that allows for the addition of 1-butene gas (15-24 psi, 86-138 mol), see
[0472] These catalytic loadings gave TON(90%) of ca. 6000 for catalysis.
Example 4
Transfer Dehydrogenation Catalytic Studies
[0473] The ability for [1-NBA][BAr.sup.F.sub.4]-crushed and [1-(ethene).sub.2][BAr.sup.F.sub.4]-Hex to mediate the gas/solid transfer dehydrogenation of butane to butenes has been briefly explored (Scheme 3), as monitored by gas-phase NMR spectroscopy. A typical experiment was as follows a high pressure NMR tube (sealed with a Teflon stopcock) was loaded with 10 mg (0.00673 mmol) of [1-NBA][BAr.sup.F.sub.4] in an argon-filled glove box. This was then taken out of the glove box, and evacuated on a Schlenk line (<110.sup.2 mbar). To this butane gas was added (1 bar, 0.0762 mmol)) and the stopcock sealed. The gas feed was changed to ethene and set to the appropriate pressure (Table 19). The glass T-piece and connecting tubing was evacuated and refilled three times (with ethene), before the stopcock was opened. The loaded tubes were left to stand, and the reaction monitored by gas phase .sup.1H NMR of the head space.
##STR00058##
TABLE-US-00019 TABLE 19 Butane transfer dehydrogenation data using [1-NBA][ BAr.sub.4.sup.F]-crushed and [1-(ethene).sub.2][BAr.sub.4.sup.F]-Hex % conversion butane to Time Ethene:Butane Catalyst butene (hrs) Temperature ratio TON [1-NBA][BAr.sub.4.sup.F]-crushed 63% 168 80 2:1 3.86 [1-NBA][BAr.sub.4.sup.F]-crushed 40% 24 80 2:1 2.45 [1-NBA][BAr.sub.4.sup.F]-crushed 15% 72 25 1:1 1.39 [1-NBA][BAr.sub.4.sup.F]-crushed 27% 24 25 1:2 3.31 [1-NBA][BAr.sub.4.sup.F]-crushed 33% 168 25 1:2 4.04 [1-NBA][BAr.sub.4.sup.F]-crushed 18% 24 25 1:2 2.21 [1-(ethene).sub.2][BAr.sub.4.sup.F]-Hex 18% 24 25 1:2 2.21
[0474] Periodic monitoring of the head space in the NMR tube showed that slow transfer dehydrogenation was occurring to form 2-butene, presumably by slow dehydrogenation to form 1-butene (not observed) and rapid isomerization. For [1-NBA][BAr.sup.F.sub.4]-crushed, after 168 hrs at 298 K there was a 33% conversion, which equates to 4 turnovers. The catalysis was also shown to operate at 80 C. with an excess of ethene (2:1), under which conditions 68% conversion of butane to butenes is observed (TON=4). Although these turnover numbers are smaller those reported for the best solid-phase molecular catalyst Ir(PCP.sup.iPr)(C.sub.2H.sub.4) in the pentane/propene system at 240 C. (e.g. TON greater than 1000), the observation of any catalytic activity at 298 K for this challenging reaction is encouraging. It is believed that this is the first time solid/gas transfer dehydrogenation has been reported using a well-defined molecular catalyst at room temperature and low pressures.
Example 5
Dimerisation Catalytic Studies
[0475] The ability of [1-NBA][BAr.sup.F.sub.4]-crushed to effect the dimerization of ethene has been briefly assessed.
[0476]
[0477] While specific embodiments of the invention have been described herein for the purpose of reference and illustration, various modifications will be apparent to a person skilled in the art without departing from the scope of the invention as defined by the appended claims.
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