Synthesis, Characterization, Crystal Structures, and Antimicrobial Activities of N, N′-Bis(3-Bromo-2-Hydroxybenzylidene)-1,3-Diaminopropane and Its Dinuclear Copper(II) Complex

A new bis-Schiff base N, N'-bis(3-bromo-2-hydroxybenzylidene)-1,3-diaminopropane (H2L) was prepared by reaction of 3-bromosalicylaldehyde and propane-1,3-diamine in methanol. The Schiff base reacting with copper bromide in methanol afforded a new dinuclear copper(II) complex [Cu2L2]. The Schiff base and the complex were characterized by elemental analysis, H-1 NMR and IR spectra, and single-crystal X-ray diffraction. H2L crystallizes in the monoclinic space group P2(1)/c, with a = 12.8003(13), b = 10.2011(10), c = 14.3747(13) angstrom, beta = 113.633(3)degrees, V = 1719.6(3) angstrom(3), Z = 4, R-1 = 0.0509, wR(2) = 0.1091, GOOF = 1.038. The complex crystallizes in the monoclinic space group P2(1)/n, with a = 11.086(2), b = 10.5881(19), c = 15.0889(17) angstrom, beta = 110.827(2)degrees, V = 1655.5(5) angstrom(3), Z = 2, R-1 = 0.0470, wR(2) = 0.1087, GOOF = 1.025. The coordination mode of H2L to Cu atom has been studied. The Schiff base and the complex were evaluated for their antibacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence) and antifungal (Candida albicans and Aspergillus niger) activities by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) method.