Phosphorus donor chemistry of [W(CO)(Ph2PCCPPh2)(S2CNEt2)2

Abstract

Reactions of [W(CO)(Ph2PCCPPh2)(S2CNEt2)2] with [M(CO)4(pip)2](M = Cr, Mo or W; pip = piperidine) afford [W(CO){(Ph2PCCPPh2)M(CO)4}(S2CNEt2)2]. The molecular structures of all three compounds have been determined by X-ray diffraction studies and found to be isostructural. In all three cases the acetylenic bond of Ph2PCCPPh2 is co-ordinated to the tungsten(II) centre, which is also ligated by carbonyl and dithiocarbamate ligands, while both phosphorus atoms are co-ordinated to the metal tetracarbonyl fragment to form a five-membered chelate ring. The 13C-{1H} NMR data are discussed in relation to the molecular structures, and the barriers to alkyne rotation in these complexes have been established by variable-temperature 31P-{1H} NMR spectroscopy. Reactions of [W(CO)(Ph2PCCPPh2)(S2CNEt2)2] with [Co2(CO)8] and [Fe2(CO)9] afford [W(CO){(Ph2PCCPPh2)Co2(µ-CO)2(CO)4}(S2CNEt2)2] and [W(CO)(x)4Fe(Ph2PCCPPh2)Fe(CO)4}(S2CNEt2)2] respectively, which have been characterised by IR, NMR and mass spectroscopy.