A Metal‐Organic Complex Constructed from Co(II), Azo‐amide‐pyridyl and Benzenetricarboxylate Mixed Ligands: Efficient Catalysis for Selective Oxidation of Benzyl Alcohols to Benzyl Acids

Abstract By using one‐step hydrothermal synthesis, a novel metal‐organic complex containing Co(II), the azo‐amide‐pyridyl ligand (E)‐4,4′‐(diazene‐1,2‐diyl)bis(N‐(pyridin‐3‐yl)benzamide (DABA) and benzenetricarboxylate was synthesized, with a molecular formula of [Co 2 (DABA) 0.5 (MTC)(μ 3 ‐OH)(H 2 O) 2 ] ⋅ 2H 2 O (namely 1 , DABA=(E)‐4,4′‐(diazene‐1,2‐diyl)bis(N‐(pyridin‐3‐yl)benzamide, H 3 MTC=1,2,4‐benzenetricarboxylic acid) which was characterized by single crystal X‐ray diffraction, PXRD, IR spectroscopy, TGA, and XPS. In the structure of complex 1 , tetranuclear Co(II) clusters were connected by MTC to form a 2D bilayer structure and further constructed a 3D structure with DABA ligand. Complex 1 was used as an efficient heterogeneous catalyst for the oxidation of benzyl alcohol, and the conversion rate of benzyl alcohol reached 98.6 % and the selectivity of benzoic acid reached 94.8 %. In addition, complex 1 can be reused 5 times without significant loss of activity. The oxidation of benzyl alcohol with different substituents also showed satisfactory conversion and selectivity, indicating that complex 1 had good catalytic performance.