By utilizing the well-known selective xanthine oxidase inhibitor topiroxostat, a new zinc(II) complex Zn(L) 2 (H 2 O) 2 ( 1 ) [HL = 4-(3-(pyridine-4-yl)-1 H -1,2,4-triazol-5-yl)picolinic acid] has been hydrothermally synthesized, involving in-situ ligand formation upon hydrolysis of topiroxostat. The complex has been structurally characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. X-ray structural analysis revealed that complex 1 is a N,O-chelating mononuclear Zn(II) complex. Complex 1 shows good thermal stability and exhibits photoluminescence in the solid state at room temperature. Moreover, complex 1 has been shown to be effective in the solvent-free ring-opening polymerization of ε -caprolactone without any co-catalyst or initiator.