Carbonyl halides of the Group VI transition metals. IX. Complexes with Bis(diphenylarsino)methane: Some further carbon monoxide carriers

Abstract

Complexes of the types MX₂(CO)₃(dam)₂ and MX₂(CO)₂(dam)₂ [M = Mo, W; X = Cl, Br; dam = bis(diphenylarsino)methane] have been prepared and characterized. The compounds are all non-electrolytes; in the tricarbonyls both of the potentially bidentate arsenic ligands are in fact acting only as monodentates, but in the dicarbonyls there is mixed coordination with one ligand monodentate and the other bidentate. The dicarbonyl complexes absorb carbon monoxide in solution at room temperature and pressure, a metal-arsenic bond of the bidentate ligand is broken, and the corresponding tricarbonyl compound is produced. The reaction is readily reversible; thus the system is an example of a carbon monoxide carrier.