LONG-CHAIN BI- AND TRI-DENTATE PHOSPHINES AS LIGANDS IN CARBONYLVANADIUM COMPLEXES

Article abstract of DOI:10.1016/S0022-328X(00)82436-5

The potentially tridentate ligands PCy(CH2CH2PPh2)2 (pcy(pph2)2) and PPh(CH2CH2PCy2)2 (pph(pcy2)2), p₃, react with and CpV(CO)4 under UV irradiation to form the mononuclear chelate five-ring complexes cis-3> and cis-, and the dinuclear CpV(CO)2μ-p₃(CO)3VCp (where the basic structure of the unit is a five-membered ring).Reaction between the carbonyl complexes and the bidentate ligands Ph2P(CH2)nPPh2 (p₂(n); n=5, 6) affords 2-μ-p₂(n) and CpV(CO)3-μ-p₂(n)CpV(CO)2p₂(n).There is also spectroscopic evidence for the formation of 3>, mer-3>, 23V(CO)5> and a species n <μ-pph(pcy2)2>2 (n=2 or 3).Structural assignments are based on IR, 31P and 51V NMR data.The coordination behaviour of p₃ and p₂(n) is compared with that of other bi- and tridentate phosphine ligands.