Complexes du titane et du zirconium contenant les ligands cyclopentadienyldiphenylphosphine et cyclopentadienylethyldiphenylphosphine: acces a des structures heterobimetalliques

Abstract

Reactions of Ph 2P(CH 2) n (C 5H 4)Li, ( n = 0, 2), with MCl 4 or CpTiCl 3 (M = Ti, Zr; Cp = η 5-C 5H 5) form Cl 2M[(η 5-C 5H 4)(CH 2) n PPh 2] 2 or Cl 2CpTi[(η 5-C 5H 4)-(CH 2) 2PPh 2] in good yields. Chemical reduction with Al, or electrochemical reduction of these complexes, under CO, are described. The titanium(IV) and zirconium(IV) derivatives react with metal carbonyls (Mo(CO) 6, Cr(CO) 6, Fe(CO) 5, Mo(CO) 4(C 8H 12)) under formation of new heterobimetallic complexes. Reduction with Al of Cl 2CpTi[(η 5-C 5H 4)(CH 2) 2PPh 2]Mo(CO) 5 under CO results in a new heterobimetallic species containing low valent titanium. Both complexes Cl 2M[(η 5-C 5H 4)(CH 2) 2PPh 2] 2 (M = Ti, Zr) react with [Rh(μ-Cl)(CO)(C 2H 4)] 2 to yield {RhCl(CO)(Cl 2M[(η 5-C 5H 4)(CH 2) 2PPh 2] 2)} x, which is assumed to be a dimer, in which the titanium or the zirconium compounds act as bridging diphosphine ligands between the rhodium atoms.