| 1. |
- Thomas, HS, et al.
(författare)
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- 2019
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swepub:Mat__t
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| 2. |
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| 3. |
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| 4. |
- Brink, A., et al.
(författare)
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Fast and reversible insertion of carbon dioxide into zirconocene-alkoxide bonds. A mechanistic study
- 2014
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 43:23, s. 8894-8898
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Tidskriftsartikel (refereegranskat)abstract
- In two consecutive equilibria the compound (Cp*)(2)Zr(OMe)(2) undergoes insertion of CO2 to form the mono- and bis-hemicarbonates. Both equilibria are exothermic but entropically disfavoured. Magnetisation transfer experiments gave kinetic data for the first equilibrium showing that the rate of insertion is overall second order with a rate constant of 3.20 +/- 0.12 M-1 s(-1), which is substantially higher than those reported for other early transition metal alkoxides, which are currently the best homogeneous catalysts for dimethyl carbonate formation from methanol and CO2. Activation parameters for the insertion reaction point to a highly ordered transition state and we interpret that as there being a substantial interaction between the CO2 and the metal during the C-O bond formation. This is supported by DFT calculations showing the lateral attack by CO2 to have the lowest energy transition state.
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| 5. |
- Muller, A, et al.
(författare)
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trans-Carbonylchlorobis(tribenzylphosphine)-rhodium(I)
- 2002
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Ingår i: Acta Crystallographica Section E: Structure Reports Online. - 1600-5368. ; 58:12, s. 715-717
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Tidskriftsartikel (refereegranskat)abstract
- The title compound, [ RhCl( PBz(3))(2)( CO)] [ PBz(3) = tribenzylphosphine, P(C7H7)(3)], which is the first reported tribenzylphosphine - rhodium( I) structure, has pseudo- square- planar coordination geometry, with Rh - P bond distances of 2.3164 ( 15) and 2.3156 ( 16) Angstrom. The Rh - Cl, Rh - C and C - O bond distances are 2.3654 ( 15), 1.783 ( 6) and 1.162 ( 6) Angstrom, respectively, and the angles P - Rh - P, P - Rh - Cl ( 2 occurrences) and C - Rh - Cl are 177.67 ( 6), 90.86 ( 5), 87.11 ( 5) and 178.55 ( 17)degrees, respectively. Effective cone angles for PBz(3) are 170 and 172degrees, while the Tolman cone angles are 171 and 173degrees. Each tribenzylphosphine has one benzyl C atom close to the coordination plane, with C - P - Rh - CO torsion angles of. 1.6 ( 3) and. 30.2 ( 3)degrees, and with the benzyl C atoms in a gauche conformation relative to the P ... P axis. DFT ( density functional theory) calculations, optimizing the geometry of the complex in the gas phase, approximately reproduce this conformation, showing that it is only slightly affected by the crystal- packing arrangement.
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| 8. |
- Otto, S, et al.
(författare)
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Tertiary phosphine abstraction from a platinum(II) coordination complex with SeCN-: Crystal and molecular structures of Se=PTA and [Se=PTA-Me]I center dot CH3OH
- 2005
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 690:19, s. 4337-4342
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Tidskriftsartikel (refereegranskat)abstract
- Reacting [PtCl(PTA)(3)]Cl (PTA = 1,3,5-triaza-7-phosphatricyclo[3.3.1.1(3,7)]decane) with KSeCN in aqueous or MeOH medium results in the abstraction of the PTA ligands to yield Se = PTA. The reaction also proceeds quantitatively by direct reaction of PTA and KSeCN in water or methanol. The methylated PTA ligand, [PTA-Me]I (1-methyl-1-azonia-3,5-diaza-7-phosphatricyclo[3.3. 1.1(3,7)]decane iodide), reacts accordingly with KSeCN, albeit significantly slower. The crystal structure of Se = PTA, 1, and [Se = PTA-Me]I - CH3OH, 2, revealed P = Se bond distances of 2.0991(19) and 2.100(2) angstrom, respectively. The first order phosphorous selenium coupling constants, (1)J(P-Se) (D2O), of 722 and 788 Hz for Se = PTA and [Se = PTA-Me]I, respectively, indicates the latter is significantly less electron rich.
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| 9. |
- Sam, Z A, et al.
(författare)
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{mu-2-[1-(N,N-Dimethylamino)ethyl]ferrocene-1,1 '-diylbis(diphenylphosphine)-kappa P-2 : P '}-bis[chlorogold(I)]
- 2005
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Ingår i: Acta Crystallographica Section E: Structure Reports Online. - 1600-5368. ; 61:10, s. 2090-2092
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Tidskriftsartikel (refereegranskat)abstract
- The structure of the title compound, [ Au2Fe( C21H23NP)( C17H14P) Cl-2], displays the pseudo-linear [ P - Au - Cl = 175.4 ( 1) and 174.0 ( 1) degrees] two-coordinate geometry usually observed in gold( I) complexes. The Au - P bond distances are 2.237 ( 2) and 2.224 ( 2) angstrom and the Au - Cl distances are 2.271 ( 3) and 2.278 ( 2) angstrom. The bis( diphenylphosphino)ferrocenyl ligand links the gold metal centres in a bidentate fashion via the ferrocene group, thus leading to a binuclear gold system.
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