Electron-rich metal complexes for C02 and CS2 incorporation

Abstract

The dihapto coordination of two molecules of carbon dioxide to a square-planar MoP2(P-P) fragment (P=monodentate-, P-P=bidentate phosphi- ne ligands) can occur in several ways giving rise to different conformers. Compounds of this type have been prepared and their spectroscopic proper- ties investigated by variable temperature 'H and 31P NMR studies. The for- mation of ethylene complexes related to Mo(C2H4)2(PMe3)4, 6, and the study of their reactivity towards carbon dioxide and carbon disulphide is also described. In particular, compound 6 induces a head-to-tail dimerization of carbon disulphide with formation of a Mo(II)-C$4 linkage, which, in the presence of carbon monoxide, undergoes a symmetric, oxidative rupture, which produces a Mo(0) complex and two molecules of carbon disulphide. The insertion reactions of carbon dioxide and other unsaturated molecules into the nickel-carbon bonds of the nickelacyclopentene complexes 9 have been investigated and different organic products isolated by means of simple or sequential insertion reactions.