Instant ligands. Part 1. Preparation of some bidentate fluorophosphine ligands derived from straight chain organic substrates, and their reactions to form molybdenum complexes

Abstract

The compounds (F₂P)S(CH₂)_nS(PF₂)(n= 2–6) and (F₂P)O(CH₂)_nO(PF₂)(n= 3–6) have been prepared by reactions of S(PF₂)₂ with the appropriate dithiols and diols, and have been characterised by n.m.r. and i.r. spectroscopy. N.m.r. parameters for oxygen compounds with n= 7–10 and 12 have also been obtained. The compounds react with N-methylpyridinium pentacarbonyliodomolybdate to give compounds with two Mo(CO)₅ units linked by the ligands. With tetracarbonyl(norbornadiene)molybdenum two types of products can be formed, depending on ligand chain length. The predominant products for n= 3–6 have two bidentate ligands bridging between two cis-Mo(CO)₄ units. For n= 2, 3, or 4 monomeric species with a single chelating ligand on a cis-Mo(CO)₄ unit are also generated, and their abundance depends on the concentrations of reactants. The metal complexes have been characterised by n.m.r., i.r., and mass spectroscopy.