Bidentate metalloligands containing the phosphinocyclopentadienyl ligand. New heterobimetallic complexes and crystal structure of (C5Me5)(C5H4PPh2)Ta(CO)(µ-PPh2)Cr(CO)4

Abstract

Four new kinds of metalloligands Cp*(C₅H₄PPh₂)TaL_n [L_n = (H)₃, (H)(CO), (H)₂(PPh₂), (CO)(PPh₂)] 2, 3, 4b, 5b containing the diphenylphosphinocyclopentadienyl ligand have been prepared and characterized. The trihydride complex 2 was obtained by reduction of the dichloride compound Cp*(C₅H₄PPh₂)TaCl₂ 1. Treatment of 2 under a CO atmosphere at 140 °C in decane affords the monohydride complex 3. Compounds 2 and 3 easily react with chlorophosphines leading to phosphido derivatives 4b and 5b respectively. All these metalloligands act as monodentate and/or chelating bidentate ligands. Their reactivity toward unsaturated organometallic fragments [M′(CO)₅] or [M′(CO)₄] (M′ = Cr, W) has been studied. The X-ray crystal structure of Cp*(C₅H₄PPh₂)Ta(CO)(µ-PPh₂)Cr(CO)₄ 10Cr is reported.