title: Biphenolate phosphine complexes of group 4 metals.
abstract: The preparation and structural characterization of a series of group 4 complexes supported by 2,2'-phenylphosphinobis(4,6-di-tert-butylphenolate) ([OPO]2-) are described. The reaction of either H2[OPO] with Ti(OR)4 (R = Et, iPr) or Li2[OPO] with TiCl4(THF)2 produced yellowish-orange crystals of Ti[OPO]2, regardless of the stoichiometry of the starting materials employed. Comproportionation of the bis-ligand complex Ti[OPO]2 with 1 equiv of TiCl4(THF)2 led to the formation of [OPO]TiCl2(THF) as brownish-red crystals. Surprisingly, treatment of H2[OPO] with [(Me3Si)2N]2MCl2 (M = Zr, Hf), irrespective of the molar ratio, generated colorless crystals of the corresponding bis-ligand complex [OPO]2M(OH2) as an aqua adduct. The solution and solid-state structures of these group 4 complexes were all characterized by multinuclear NMR spectroscopy and X-ray crystallography, respectively.
authors.affiliation: Department of Chemistry and Center for Nanoscience & Nanotechnology, National Sun Yat-sen University, Kaohsiung 80424, Taiwan. lcliang@ mail.nsysu.edu.tw
authors.forename: Lan-Chang
authors.initials: LC
authors.lastname: Liang
authors.forename: Yu-Ning
authors.initials: YN
authors.lastname: Chang
authors.forename: Hon Man
authors.initials: HM
authors.lastname: Lee