Formation and structure of a bis(cyclopentadienyl)(formamidinato)zirconium cation complex

摘要

Deprotonation of N,N'-dicyclohexylformamidine with methyl lithium yields dicyclohexylformamidinyl lithium (8a). The X-ray crystal structure analysis of 8a shows an unsymmetically formamidinato-bridged THF-stabilized dimer in the crystal. Treatment of diphenylformamidinyl lithium (8b) with Cp2ZrCl2 gives the (kappa(2) N, N'-diphenylformamidinato)Cp2ZrCl complex 6b which was also characterized by X-ray diffraction, as was (kappa(2) N, N'-dicyclohexylformamidinato)(CpZrCH3)-Zr-2 (7a). Treatment of (kappa(2) N, N'-diphenylformamidinato)Cp2ZrCH3 (7b) with [Bu3NH+][BPh4-] gave the salt [(kappa(2) N, N'-diphenylformamidinato)Cp2Zr+][BPh4-] (9B). Its X-ray crystal structure analysis revealed a symmetrical bonding of the formamidinato ligand to the zirconium metal center.