Contributions to the structural chemistry of 2-amino alcoholate derivatives of titanium and zirconium alkoxides and their partial hydrolysis products

摘要

The structures of Ti-2(OiPr)(6)(OCHMeCH2NH2)(2) and Ti-2(OiPr)(6)(OCH2CHMeNH2)(2), obtained by reaction of Ti(OiPr)(4) with the corresponding amino alcohols, were investigated to elucidate the structural influence of the organic substituents at the amino alcohol. A methyl group at the OH-substituted carbon atom results in a larger distortion of the structure than a methyl group at the NH2-substituted carbon. The disubstituted compound Ti-2(OiPr)(4)(OCH2CH2NH2)(4) was formed, when NaTi(OiPr)(5) was reacted the amino ethanol. While one OCH2CH2NH2 ligand is chelating, the oxygen atom of the second bridges the titanium atoms, and the NH2 group is dangling. The structures of the partial hydrolysis products Ti4O4(OiPr)(4)(OCHPhCHMeNHMe)(4) and Ti8O6(OEt)(12)(OCH2CH2NH2)(8) were also investigated. The former contains an incomplete double-cube Ti4O4 cluster core, the latter is made of two Ti4O3(OEt)(6)(OCH2CH2NH2)(4) sub-units, with a nearly planar Ti-4(mu(2)-O)(2)(mu(3)-O)(mu(2)-OEt)(2) ring system, connected by two OEt bridges. Zr(OCH2CH2NH2)(4) is a mononuclear compound with four chelating amino alcoholate ligands. The structure of Zr-6(OBu)(18)(OCH2CH2NH2)(6) is assembled from two Zr-2(OBu)(5)(OCH2CH2NH2)(3) and two Zr(OBU)(4) sub-units, which are associated by alkoxo bridges.