Chelating Ether-Phosphine Complexes of the Cobalt Group Metals. Crystal Structures of Bis-bis(trifloromethanesulfonato)cobalt(II) and -trichlororhodium(III)

DOI: 10.1039/DT9950003551

Source and publish data:

Journal of the Chemical Society, Dalton Transactions p. 3551 - 3560 (1995)

Update date:2022-08-04

Topics:

Authors:

Chadwell, Steven J.

Coles, Simon J.

Edwards, Peter G.

Hursthouse, Michael B.

Read Full Text PDF DownLoad Join now for total 90,000,000 free articles

Article abstract of DOI:10.1039/DT9950003551

New Group 9 metal complexes have been prepared using the trifunctional ligand benzylbis(2-ethoxyethyl)phosphine (L).Reactions of this potentially hemilabile ligand with CoCl2, and CoCl2*6H2O with AgCF3SO3, have been studied, resulting in the isolation of 1 and 2 respectively.In the former complex L acts as a monodentate P-bonding ligand with the metal adopting a tetrahedral geometry, but in the latter it acts as an O,P chelate.The crystal structure for 2 has been determined and shows the metal to have a distorted-octahedral geometry with trans ligands (P and O) and trans triflates.The 31P-<1H> NMR spectrum of 2 suggests the formation of a dimeric species in solution.Reactions of L with RhCl3*3H2O, <2> and <2> (cod = cycloocta-1,5-diene) resulted in the isolation of 3, 4 and 5 respectively, where L acts as a monodentate P-bonding ligand in 4 and 5.Complex 4 is shown to be trans by NMR studies.In 3 the ligand bonds as a monodentate phosphorus donor in one case and as a bidentate O,P chelate in the other.The crystal structure of 3 has been determined and shows the metal to have a slightly distorted-octahedral mer arrangement with cis phosphorus donors.The fluxional nature of this complex has been monitored by variable-temperature 31P-<1H> and 1H NMR spectroscopy which shows that these ligands readily interchange at high temperatures.The iridium analogue of 5 has been prepared from <2> resulting in the isolation of 6.The reaction of 3 with cyclohexene gave an unstable alkene complex 7 which could not be isolated, but was identified by variable-temperature 31P-<1H> NMR studies.