Synthesis, Characterization, Crystal Structure, and Antimicrobial Activity of a Novel Dinuclear Zinc(II) Complex Derived From N,N′-Bis(5-Fluoro-2-Hydroxybenzylidene)-1,3-Diaminopropane

Abstract

A new dinuclear zinc(II) complex derived from the bis-Schiff base ligand N,N'-bis(5-fluoro-2-hydroxybenzylidene)-1,3-diaminopropane (H₂L) was prepared and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P2₁/c, with a = 10.100(1), b = 8.953(1), c = 27.664(1) Å, β = 106.406(2)°, V = 2399.8(3) ų, Z = 4, R₁ = 0.0785, wR₂ = 0.1336, S = 1.067. The ZnZn distance is 3.106(1) Å. The inner Zn atom is in a square pyramidal coordination, with two imino N and two phenolate O atoms of the Schiff base ligand defining the basal plane, and with one methanol O atom locating at the apical position. The outer Zn atom is coordinated by two phenolate O atoms and two Br atoms, forming a tetrahedral coordination. The molecules are linked through O–HO and O–HBr hydrogen bonds, forming 1D chains along the b axis. The free Schiff base and the zinc complex were evaluated for their antibacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescens) and antifungal (Candida albicans and Aspergillus niger) activities by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) method.

Keywords:

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