191609-16-2Relevant academic research and scientific papers
Oxidative additions of coordinated ligands at unsaturated molybdenum and tungsten diphosphine-bridged carbonyl dimers. 3. Decarbonylation reactions of [MoW(η5-C5H5)2(CO) 4(μ-Ph2PCH2PPh2)]
Alvarez, Celedonio,Garci?a, M. Esther,Riera, Vi?ctor,Ruiz, Miguel A.
, p. 1378 - 1383 (2008/10/08)
Decarbonylation of the heterometallic title complex [MoWCp2(CO)4(μ-dppm)] (Cp = η5-C5H5; dppm = Ph2PCH2PPh2) in refluxing tetrahydrofuran leads to the phosphido complex [MoWCp2(μ-CH2PPh2)(μ-PPh 2)(CO)2], presumably via the tricarbonylic species [MoWCp2(μ-CH2PPh2)(μ-PPh 2)(μ-CO)(CO)2]. The latter is an unstable compound which can be generated upon reaction of the former with CO and also contains the phosphinomethyl ligand C-bonded to the tungsten atom. In contrast, photolytic decarbonylation of the title complex at -10 °C leads reversibly to the hydrido compound [MoW(μ-η1:η5-C5H 4)Cp(μ-H)(CO)3(μ-dppm)], in which the cyclopentadienylidene ligand is specifically η5-bonded to tungsten and η1-bonded to molybdenum. Further photolysis of this complex at 10 °C leads to the triply bonded dimer [MoWCp2(CO)2(μ-dppm)] with concomitant regeneration of a H-C (cyclopentadienyl) bond. The latter species reacts with tBuCN to give [MoWCp2(μ-η1:η2-CN tBu)(CO)2(μ-dppm)], in which the isocyanide ligand is specifically η1-bonded to tungsten and η2-bonded to molybdenum. In order to account for the metal selectivity observed in the above species, two different intermediates, having either μ-η1-CO or μ-η1:η2-CO ligands, are thought to be involved in the decarbonylation reactions of the title compound.
