Co-ordinatively unsaturated alkyne complexes of molybdenum and tungsten. Reactions of [MCl(CF3CCCF3)2(η-C5H5)](M = Mo or W) with heterocyclic thiolates leading to η2-vinyl complexes
Abstract
Reactions of Tl(SR)(SR–= pyridine-2-thiolate, pyrimidine-2-thiolate, or thiazoline-2-thiolate) with the bis(hexafluorobut-2-yne) complex [MoCl(CF3CCCF3)2(η-C5H5)] give products [[graphic omitted]}(CF3C-CCF3)(η-C5H5)] containing a novel η2-vinyl ligand resulting from nucleophilic attack of nitrogen on a co-ordinated alkyne. The same pyridine-2-thiolate complex is obtained from the reaction of [MoCl(CF3CCCF3)2(η-C5H5)] with the thallium(I) salt of 2-mercaptopyridine N-oxide, in addition to [[graphic omitted]}(η-C5H5)]. The complex [WCl(CF3CCCF3)2(η-C5H5)] reacts with thallium(I) pyridine-2-thiolate to give the η2-vinyl complex [[graphic omitted]}(CF3CCCF3)(η-C5H5)], whereas with Tl(SC5H4NO) cyclopentadienyl-ligand displacement is also observed giving the co-ordinatively unsaturated bis(hexafluorobut-2-yne) complexes [W(SC5H4NO)2(CF3CCCF3)2] and [W(SC5H4N)(SC5H4NO)(CF3CCCF3)2]