100655-35-4Relevant academic research and scientific papers
Preparation and structural dynamics of phosphine-bridged trirhodium chains. Observation of facile bridge/terminal interchange of anionic ligands or carbon monoxide
Balch, Alan L.,Fossett, L. Alan,Guimerans, Rosalvina R.,Olmstead, Marilyn M.,Reedy Jr., Philip E.,Wood, Fred E.
, p. 1248 - 1253 (2008/10/08)
The preparations of the trirhodium chain compounds [Rh3(μ-dpmp)2(CO)3X2][BPh 4] (dpmp is bis((diphenylphosphino)-methyl)phenylphosphine; X = Cl-, Br-, I-, N3-, NCO-) and [Rh3(μ-dpma)2(CO)3X2] [BPh4] (dpma is bis((diphenylphosphino)-methyl)phenylarsine; X = Cl-, Br-, I-) are reported. Infrared and multinuclear (1H, 31P, 13C) NMR spectra along with the previously reported X-ray crystallographic data on [Rh3(μ-dpmp)2(CO)3(μ-Cl)Cl]+ and [Rh3(μ-dpmp)2(μ-CO)(CO)2(μ-I) 2]+ allow these cations to be sorted into three classes. All classes contain a Rh3(dpmp)2 or Rh3(dpma)2 core with trans P-Rh-P and As-Rh-As units. The cations [Rh3(μ-dpmp)2(CO)3(μ-X)X]+ (X = Cl-, N3-, NCO-) and [Rh3(μ-dpma)2(CO)3(μ-X)X]+ (X = Cl-, Br-) possess a structure with one bridging X and only terminal carbonyls. In solution these undergo rapid bridge/terminal halide exchange. The cations [Rh3(μ-dpmp)2(μ-CO)(CO)2(μ-I) 2]+ and [Rh3(μ-dpma)2(μ-CO)(CO)2(μ-I) 2]+ both possess a static structure in solution that is the same as the solid-state structure. One Rh-Rh unit is bridged by a carbonyl and an iodide. That iodide is close to the third rhodium, which is also bridged to the central rhodium by a shorter iodide bridge. The structure of [Rh3(μ-dpmp)2(μ-CO)(CO)2Br 2]+ is unique. In solution it undergoes rapid bridge/terminal carbonyl exchange, which leaves one of the terminal carbonyl groups unaffected. This cation crystallizes in two modifications, a violet one without a bridging carbonyl and a tan one with an apparent structure similar to that found in solution.
