Dicarboxylate Ligands Oriented Assembly of {Ti 3 (μ 3 -O)} Units: From Dimer to Coordination Triangles and Rectangles.

A series of dicarboxylates bridged titanium-oxo clusters with {Ti3 (μ3 -O)} building units have been synthesized through facile one-step solvothermal reactions. It is interesting to find that the geometric characteristics of the obtained supramolecular structures highly depend on the configuration of the applied dicarboxylate ligands. A linear dimeric [Ti3 O]2 L2 complex can be constructed using flexible cyclohexanedicarboxylic acid, while the introduction of rigid 2-nitro-1,4-benzenedicarboxylic acid gives rise to a triangular [Ti3 O]3 L3 structure. Moreover, unusual [Ti3 O]4 L4 rectangles have been achieved with more symmetric 5-nitro-1,3-benzenedicarboxylic acid or terephthalic acid. Furthermore, a photochromic effect is observed on the obtained complexes upon UV-vis light irradiation in the presence of alcohol.