Bidentate phosphinophenol ligand: Synthesis and characterization of oxo and phenylimido rhenium(V) complexes of 2-diisopropylphosphinophenol

Article abstract of DOI:10.1016/S0277-5387(00)00360-0

Six-coordinate, monosubstituted and disubstituted phosphinophenol complexes ReYX₂ (PPh₃) (P ~ O) and ReYX (P ~ O)₂ (Y = O, NPh; X = Cl, Br, I) were obtained by reacting 2-diisopropylphosphinophenol (P ~ OH) with ReOX₃(PPh₃)₂ and Re(NPh)X₃(PPh₃)₂ in toluene. A mixture of the monosubstituted and disubstituted complexes ReYX₂(PPh₃) (P ~ O) and ReYX(P ~ O)₂ was precipitated when the reactions were performed with a 2:1 ligand to metal ratio. Excess ligand (4 equiv.) was needed to obtain quantitatively the disubstituted complexes. ¹H and ³¹P{¹H} NMR show that all monosubstituted and disubstituted complexes exist as single isomers with a trans-P,P 'twisted' octahedral geometry, the site trans to the multiple bond being filled by the oxygen donor of one P ~ O ligand. The compounds were also characterized by microanalysis, IR and mass spectrometry. (C) 2000 Elsevier Science Ltd.