Instant ligands. Part 2. Preparation of some bidentate ligands containing PF2O groups from aromatic hydroxy compounds, and their reactions to form molybdenum and tungsten complexes

Abstract

Three isomers of C₆H₄(OPF₂)₂, two of (C₆H₄OPF₂)₂, and seven of C₁₀H₆(OPF₂)₂ have been prepared by reactions of S(PF₂)₂ and the appropriate dihydroxy derivatives of benzene, biphenyl, and naphthalene, respectively. From these bidentate ligands, complexes have been prepared containing two Mo(CO)₅ units or one Mo(CO)₅ and one W(CO)₅ unit linked by the ligands. With tetra-carbonyl(norbornadiene)molybdenum, cyclic products with ligands bridging between cis- Mo-(CO)₄ units are formed. The relative stabilities of the various cyclic oligomers depend on the distance between the phosphorus donor sites, which varies widely in this set of ligands.