192726-25-3Relevant academic research and scientific papers
Substitution of chloride in [PtCl2(PEt3)2] by the chiral anionic ligand [Mo(CO)5(PPhH)]- to give mixed platinum-molybdenum compounds and a 31P{1H} NMR analysis of their fluxionality. X-ray crystal structure of [PtCl(PEt3)2
Deeming, Antony J.,Cockerton, Bruce R.,Doherty, Simon
, p. 1945 - 1956 (2008/10/09)
Deprotonation of the primary phosphine complex [Mo(CO)5(PPhH2)] generated [Mo(C-O)5(PPhH)]-, a chiral anionic ligand which reacted readily with cis-or trans-[PtCl2(PEt3)2] via facile nucleophilic substitution of one or both chloride ligands to afford trans-[PtCl(PEt3)2(μ-PPhH){Mo(CO)5}] (1) and cis- and trans-[Pt(PEt3)2(μ-PPhH)2{Mo(CO) 5}2] (2), respectively. These are rare examples of heterometallic complexes containing primary phosphido bridges. Compound 1 can be described either as the square-planar PtII complex with the anionic ligand PPhH{Mo(CO)5}- or as the Pt-Mo phosphido-bridged dimer trans-[PtCl(PEt3)2(μ-PPhH){Mo(CO)5}]. As a phosphido-bridged heterobimetallic 1 possesses an exceptionally large Pt-P-Mo angle [120.9(1)°] reflecting the long Pt-Mo nonbonding interaction (4.5 A). Compound 2 can correspondingly be described either as a phosphido-bridged PtMo2 trimer or a square-planar arrangement of two neutral PEt3 and two anionic PPhH{Mo(CO)5} ligands at Pt. The low-temperature 31P{1H} NMR spectrum of 1 showed several ABXY spin systems together with their associated ABXYM (M = 195Pt) counterparts and variable-temperature studies revealed the dynamic interconversion of several rotametric isomers arising from restricted rotation about the Pt-Pμ bond. The 31P{1H} NMR spectrum of trans-2 shows its two possible RR/SS and meso diastereoisomers, the latter existing in clearly identifiable rotameric forms which interconvert slowly at -75°C. We note very different values between 2J(P-P) and 1J(195Pt-P) for the anionic ligands [PPhH{Mo(CO)5}]- and PEt3, unattributable to bond length variation but which must reflect reduced s-orbital contribution to the Pt-P bond of the anionic phosphines PPhH{Mo(CO)5}.
