The synthesis of [Ti(O-i-Pr)Cl2(PhCHO)(μ-Cl)]2 and its reactions with oxygen-containing ligands L (L=DMF, DMSO, i-PrOH). The crystal structure of Ti(O-i-Pr)Cl3(PhCHO)(i-PrOH) and the 1H variable-temperature NMR studies of solution structures of [Ti(O-i-Pr

Ti(O-i-Pr)Cl3 reacted with 1 molar equiv. of benzaldehyde to give the dimeric complex [Ti(O-i-Pr)Cl2(PhCHO)(μ-Cl)]2 (2) which reacted further with 2 molar equiv. of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or 2-propanol (i-PrOH) to give the six-coordinate monomeric complexes Ti(O-i-Pr)Cl3(PhCHO)L (L=DMF (3), DMSO (4), or i-PrOH (5)). In the reaction of 2 with i-PrOH, the formation of the simple adduct 5 demonstrates the preferred nature of the monomeric six-coordinate species to the chloride-bridged or the alkoxide-bridged dimeric complex. The complexes 2–5 are highly dynamic in solution and the 1H variable-temperature NMR studies show 17 observable CHO signals for the chloride-bridged dimeric complex 2, indicating the presence of more than 10 isomeric species in solution. For the monomeric complexes 3 and 4, all four geometric isomers are observed. For the complex 5, however, the observation of 11 benzaldehyde CHO signals indicates the presence of hydrogen-bonded dimeric species in solution in addition to the four expected monomeric isomers. The solution structures of complexes 2–5 are discussed. For the complex 5, the dynamic process for the exchange of the hydroxy hydrogen between the O-i-Pr and the i-PrOH ligands is observed. Despite the presence of several isomeric speices in solution, the lowest-enegy species 5-A crystallizes in the triclinic P1̄ space group with a=8.976(2), b=10.412(2), c=11.744(2) Å, α=67.49(1), β=69.18(1), γ=71.68(1)°, z=2, R=0.043, Rw=0.064, and Gof=1.57. The solid state structure of 5-A exhibits the trans position of the benzaldehyde ligand relative to the 2-propoxide ligand, suggesting a relative bonding order of −O-i-Pr>Cl−>i-PrOH>PhCHO.