Chemistry of Ti(OiPr)Cl3 with Chloride and Oxygen-Containing Ligands: The Roles of Alkoxide and Solvents in the Six-Coordinate Titanium Complexes

Ti(OiPr)Cl3 reacts easily with various ligands to form a series of six-coordinate complexes, [Ti(OiPr)Cl5]2-(HAm+)2 (Am = NEt3 (7a) or NC5H5 (7b)), Ti(OiPr)Cl3L2 (L = THF (8) or PhCHO (9)), Ti(OiPr)Cl3(PhCHO)(Et2O) (10), and [Ti(OiPr)Cl2(μ-Cl)(PhC(O)OMe)]2 (11). Upon dissolution of 7a in THF, 8 was obtained. When 1 mol equiv of HNEt3Cl was added to 8, [Ti(OiPr)Cl4(THF)]-(HNEt3)+ (12) was obtained. With the addition of another 1 mol equiv of HNEt3Cl, 12 was converted to 7a. One THF in 8 can be removed in vacuo to give the chloride-bridged dimer [Ti(OiPr)Cl2(μ-Cl)(THF)]2 (13) which can be converted back to 8 by dissolving in THF. 13 was found to react with 2 mol equiv of HNEt3Cl or PhCHO to give 12 and Ti(OiPr)Cl3(PhCHO)(THF) (14), respectively. The molecular structures of 7b, 8, and 10−13 show short Ti−OiPr distances, and the relative bonding order of -OiPr > Cl- > THF > Et2O > PhCHO > μ-Cl- > RC(O)OMe is discussed based on the solid state structures. This bonding sequence is very useful for the prediction...