Syntheses and characterization of some homodimer complexes of bismuth(III) having a Bi…Bi linkage along with molecular modeling, antimicrobial, antioxidant and cytotoxic studies

Abstract

A homodimer of bismuth(III) heteroleptic derivatives having two ligands, [{(R¹)(R²)C = NO}₂Bi{S₂CN(CH₂CH₂)₂O}]₂ [where R¹ = -C₆H₅, R² = -CH₃ (1); R¹ = -C₆H₄CH₃, R² = -CH₃ (2); R¹ = -C₆H₄Cl, R² = -CH₃ (3); R¹ = -C₆H₄Br, R² = -CH₃ (4); R¹ = -C₆H₄OH, R² = -H (5); R¹(R²)C = C-CH₂-(CH₂)₃-CH₂ (6)], were synthesized by reaction of bismuth(III) chloride with sodium substituted oximes and morpholine dithiocarbamate in 1:2:1 stoichiometry. The complex was characterized by IR, ¹H and ¹³C NMR spectra; the dimeric structure was assigned through LC-mass spectrometry. Distorted octahedral geometry around the central bismuth in each unit of the homodimer, linked by Bi…Bi bond, is proposed. Calculations for the two possible optimized geometries were done to determine Bi…Bi intermolecular linkage in these derivatives. Powder XRD study displayed nano range (∼30 nm) particle size and crystalline nature. The synthesized bismuth(III) derivatives were studied against four microbes viz., Bacillus subtilis, Escherichia coli, Aspergillus niger and Candida albicans. The antioxidant evaluation was carried out by FRAP assay and the cytotoxic study was accomplished through MTT analyzer. The results revealed that these derivatives were non-toxic (>50% cell viability) for 3 T₃ fibroblast cell lines even at 500 µg/mL concentration.

Keywords:

• Substituted oximes
• morpholine dithiocarbamate
• bismuth(III)
• cytotoxicity
• antimicrobial
• antioxidant and molecular modeling

Acknowledgements

The elemental analyses and the spectral studies were accomplished by the Sophisticated Analytical Instrument Facility (SAIF), Punjab University, Chandigarh. The antibacterial and antioxidant activities were performed at Seminal applied Sciences Pvt. Ltd, Jaipur. A computational study was performed in the Department of Computer Science, Birla Institute of Technology Mesra, Jaipur campus and powder X-ray diffraction was done by MNIT, Jaipur.

Disclosure statement

No potential conflict of interest was reported by the authors.