Computational and Thermal Characterization of a Cu(II) Thiosemicarbazone Complex Applied for Liquid-Phase Oxidation of Benzyl Alcohol

This study reports the synthesis, computational, and thermal characterization of a dimeric copper(II) coordination compound ([Cu(µ-L)]₂) based on 2-hydroxyacethophenone-N⁴-phenylthiosemicarbazone, as well as its catalytic activity in the liquid-phase oxidation of benzyl alcohol. Based on single-crystal XRD crystallography, [Cu(µ-L)]₂ crystallizes as an asymmetric dimer, where each of the two Cu(II) ions is inserted in a similar fourfold coordination environment and with L^2- acting as a tridentate ligand. Also, [Cu(µ-L)]₂ forms a one-dimensional network along the b-crystallographic axis due to two π···π stacking interactions. The latter were demonstrated to be weak van der Waals interactions that influence the disposition of the compound in the solid state and to alter the thermal decomposition of the ligand. In the catalytic reaction, [Cu(µ-L)]₂ demonstrated versatility through the tuning of its selectivity using solvents: mild selectivity towards benzaldehyde in acetonitrile, and total selectivity towards benzoic acid in DMF.