The preparation and structural characterization of a series of Tantalum complexes supported by 2,2¡¦-phenylphosphinobis(4,6-di-tert-butyl- phenolate) ([OPO]2-) are described. The reaction of Li2[OPO] with TaCl5 produced yellow crystals of [OPO]2TaCl, regardless of the stoichiometry of the starting materials employed. Alkylation of [OPO]2TaCl with a variety of Grignard reagents generated [OPO]2TaR (R = Me, Et). Formation of [OPO]2TaH arise from [OPO]2TaEt undergo £]-Hydrogen elimination at 120 oC or reaction of [OPO]2TaCl with LiHBEt3. The solid-state structures of [OPO]2TaCl, [OPO]2TaOH and [OPO]2TaH and the solution of these Tantalum complexes were characterized by X-ray crystallography and multinuclear NMR spectroscopy. A new chelating N, N ligand family incorporation an anilido- phosphinimine donor set has been designed. The ligand 1-(NHAr)-2-(PPh2=NAr)C6H4 ([NN-iPr]; Ar = 2,6-diisopropylphenyl) was prepared by Staudinger reaction with 2,6-diisopropyl- phenylazide and N-(2-diphenylphosphinopheyl)-2,6-diisopropyl-anilide. Deprotonation of H[NN-iPr] with n-BuLi in THF at -35 oC generated [NN-iPr]Li(THF). The reactions of trialkylaluminum with H[NN-iPr] produced the corresponding dialkyl complexes [NN-iPr]AlMe2 and [NN-iPr]AlEt2. The aluminum complexes were all characterized by 1H, 13C{1H}, 31P{1H}, and 27Al{1H} NMR spectroscopy. The solid-state structures of H[NN-iPr] and [NN-iPr]AlMe2 were determined by X-ray crystallography.

A tridentate diphenolate phosphine ligand H2[OPO] (bis(3,5-di-tert-butyl-2-hydroxyphenyl)phenylphosphine) has been synthesized in high yield. Treatment of H2[OPO] with Ti(OEt)4 in toluene at room temperature produced reddish orange crystalline Ti[OPO]2. The bis-ligand complex Ti[OPO]2 also be obtained from the in situ lithiation of H2[OPO] in THF or toluene followed by addition of TiCl4(THF)2. The reactions of MCl2[N(SiMe3)2]2 (M = Zr, Hf) with H2[OPO] in pentane at room temperature generated cleanly [OPO]2Zr(H2O) and [OPO]2Hf(H2O), respectively, in high yield. Treatment of TiCl4(THF)2 with Ti[OPO]2 in toluene afforded [OPO]TiCl2(THF). The solution and solid-state structures of Ti[OPO]2, [OPO]TiCl2(THF), [OPO]2Zr(H2O) and [OPO]2Hf(H2O) were studied by multinuclear NMR spectroscopy and X-ray crystallography. lithiation of H2[OPO] with n-BuLi in DME solution afforded [OPO]Li2(DME)2. The metathetical reactions of H2[OPO] with NaH or KH in DME solutions, respectively, produced the corresponding complexes [OPO]Na2(DME)2 and {[OPO]K2(DME)2}2. Both [OPO]Li2(DME)2 and [OPO]Na2(DME)2 are highly active catalysts for ring-opening polymerization of caprolactone. A series of tetravalent tin complexes [OPO]SnX2 (X = Cl, Me, n-Bu) also be obtained from the in situ lithiation of H2[OPO] in THF followed by addition of SnCl2X2. A divalent tin complexe [OPO]Sn also be obtained by analogous way from the in situ lithiation of H2[OPO] in pentane followed by addition of SnCl2.