SOLUTION DYNAMICS OF CIS-BIS(DIPHENYLPHOSPHINO)ETHENE SUBSTITUTED DERIVATIVES OF IR-4(CO)(12)

摘要

The fluxional behaviour of [Ir-4(CO)(10)(cis-Ph2PCH=CHPPh2)] (I) and [Ir-4(CO)(8)(cis-Ph2PCH=CHPPh2)(2)] (II) has been investigated by C-13 and P-31 NMR. Cluster I exists in solution as an equilibrium mixture of two geometrical isomers. Both isomers are fluxional due to two independent CO scrambling processes, and their interconversion is due to a slower P atom intramolecular migration from one metal centre to another. In contrast, the pairwise exchange of the P atoms in cluster II is not due to P atom migration but is the consequence of two parallel CO site exchange processes. [References: 33]