The reaction of 2-acetylpyridine, cyclopentylamine, and copper(II) bromide in methanol resulted in the tetranuclear copper(II) complex [Cu 4 L 2 (m-Br) 2 Br 2 ], where L is the dianionic form of 1-methoxy-1,3-dipyridin-2-ylpentane-1,3-diol. The complex was characterized by elemental analysis and IR spectroscopic method in the solid state. Single-crystal X-ray analysis was performed, which indicated that the complex possesses crystallographic twofold rotation axis symmetry. The complex crystallizes in the tetragonal space group P4 3 2 1 2 with unit cell dimensions a D b D 8.963 (1) A , c D 49.013(1) A , V D 3937.5(8) A 3 , Z D 4, R 1 D 0.0665, and wR 2 D 0.1397. The outer two Cu atoms are in tetrahedrally distorted square planar geometry. The inner two Cu atoms are in distorted square pyramidal geometry. Thermal behavior and biological property on the bacteria strains B. subtilis, E. coli, and S. aureus of the complex were studied.