Can related pyridine-alkoxide titanium complexes adopt different geometries?  A combined experimental and theoretical study

A series of new titanium pyridine−alkoxide complexes, [TiCp*Cl{2,6-(OCH2)2py-κ3-O,N,O}] (2), [TiCp*{2,6-(OCH2)py(CH2OH)-κ1-O}{2,6-(OCH2)2py-κ3-O,N,O}] (3), [TiCp*Me2{2-(OCH2)py-κ1-O}] (4), [TiCp*Me{2-(OCH2)py-κ1-O}2] (5), and [TiCp*(O){2-(OCH2)py-κ2-O,N})] (6), have been synthesized. All of these compounds were characterized by NMR spectroscopy. The single-crystal structures of [TiCp*Me{2,6-(OCH2)2py-κ3-O,N,O}] (1), 2, 3, and 4 were determined and revealed the presence of piano and nonpiano stool geometries. The molecular structures of 1, 2, and 3 were also studied by means of density functional theory (DFT) in an attempt to rationalize the possible reasons for the stabilization of one or other geometry.