Trinuclear Oxo-Titanium Clusters: Synthesis, Structure, and Photocatalytic Activity

The interest in titanium (IV) oxo-complexes is due to their potential application in photodegradation processes and environmental pollutants reduction. Titanium (IV) oxo-complexes (TOCs) of the general formula [Ti₃O(OⁱPr)₈(OOCR')₂] (R' = -C₁₃H₉ (1), -p-PhCl (2), -m-PhNO₂ (3), -C₄H₇ (4)) were synthesized and structurally characterized. The use of the different carboxylate ligands allowed modulating the optical band gaps of the produced microcrystals, which were measured via diffuse reflectance ultraviolet and visible spectroscopy (UV-Vis-DRS) and calculated using the density functional theory (DFT) method. The dispersion of TOCs (1-3) in the poly (methyl methacrylate) matrix (PMMA) led to the formation of polymer/TOCs composites, which in the next stage of our works have been applied in the photocatalytic activity estimation of synthesized trinuclear Ti(IV) oxo-complexes. Studies of the photocatalytic degradation of methylene blue (MB) induced by UV irradiation exhibit that the PMMA-TOCs composite containing (1) oxo-clusters is the most active, followed by the system containing the complex (3).