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

Abstract

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, ¹H NMR and IR spectra, and single-crystal X-ray diffraction. H₂L crystallizes in the monoclinic space group P2₁/c, with a = 12.8003(13), b = 10.2011(10), c = 14.3747(13) Å, β = 113.633(3)°, V = 1719.6(3) ų, Z = 4, R₁ = 0.0509, wR₂ = 0.1091, GOOF = 1.038. The complex crystallizes in the monoclinic space group P2₁/n, with a = 11.086(2), b = 10.5881(19), c = 15.0889(17) Å, β = 110.827(2)°, V = 1655.5(5) ų, Z = 2, R₁ = 0.0470, wR₂ = 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.

Keywords:

• antimicrobial activity
• bis-Schiff base
• copper complex
• dinuclear complex
• X-ray diffraction

Additional information

Funding

Research program of foundation and advanced technology of Henan province (project nos. 122300410386, 132309410397) were acknowledged.