N-Methyldiethanolamine-Modified Titanium Isopropoxide: X-Ray Crystal Structure of [Ti2(μ2-(OCH2CH2)2NCH3)(μ2-OPri)(OPri)5]

Abstract

A highly fluxional dititanium N-methyldiethoxoamine hexaisopropoxide complex was isolated from reactions of N-methyldiethanolamine with Ti(OPrⁱ)₄. X-ray crystallography identified the solid state compound as the unsymmetrical complex Ti₂(μ₂-(OCH₂CH₂)₂NCH₃)(μ₂-OPrⁱ)(OPrⁱ)₅. In solution, the time-averaged structure was shown by NMR to be symmetrical. The amine function coordinates to both titanium atoms alternately, while the isopropoxide ligands exchange to maintain equal coordination numbers on both titaniums. Variable temperature NMR demonstrates that the exchange processes slow on cooling, and a spectrum consistent with the solid-state structure is apparent at –50°C.