(1–3-η-Allyl)dicarbonyl-molybdenum(II) and -tungsten(II) complexes and their reactions with some chelating anions

Abstract

Complexes [MX(η-C₃H₅)(CO)₂L₂][M = Mo or W; L₂= 2.2′-bipyridyl (bipy) or di(2-pyridyl)amine (dpa); X = Cl, Br, I,NCS, MeCO₂, CF₃CO₂, PhSO₂, or p-MeC₆H₄SO₂] have been prepared by one or more of four preparative routes. The oxo-anions are all unidentate and O bonded. Reaction of the molybdenum complexes with sodium pentane-2,4-dionate and dimethyl- or diethyl-dithiocarbamate in the presence of pyridine results in displacement of halide and bipy or dpa and formation of [Mo(η-C₃H₅)(CO)₂(A)(py)](A = pd, Me₂NCS₂^–, or Et₂NCS₂^–). The salicylaldehyde anion (sal) reacts similarly with molybdenum dpa complexes but behaves as a unidentate ligand towards the corresponding bipy complexes with formation of [Mo(η-C₃H₅)(CO)₂(sal)(bipy)].