Synthesis of a new pyridinyl thiazole ligand with hydrazone moiety and its cobalt(III) complex: X-ray crystallography, in vitro evaluation of antibacterial activity. (25th September 2017)

• Record Type: Journal Article
• Authors: Bera, Pradip; Brandão, Paula; Mondal, Gopinath; Jana, Harekrishna; Jana, Abhimanyu; Santra, Ananyakumari; Bera, Pulakesh
• Is Part Of: Polyhedron. Volume 134(2017)
• Page Start: 230
• Page End: 237
• Publication Date: 2017-09-25
• Subjects: Thiazole -- Hydrazone -- Co(III) complex -- Crystallography -- Antibacterial activity; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2017.06.024
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: A ligand of pyridine–thiazole with hydrazone moiety and its Co(III) complex are synthesized and fully characterized by 1 H NMR spectroscopy of the ligand, X-ray crystallography and cyclovoltammogram analysis. The compounds are shown to be highly active towards gram positive bacteria including Staphylococcus aureus, Streptococcus faecalis and Bacillus subtilis and gram-negative bacteria including Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Klebsiella pneumonia and Proteus vulgaris. Abstract: The present work report the synthesis, structural characterization and in vitro antibacterial studies of (4-(4-methoxy phenyl)-2-(2-(1-pyridine-2-yl)ethylidene)hydrazinyl)thiazole bromide (HL·Br) and its cobalt(III) complex, [CoL2 ]ClO4 . HL⋅Br crystallizes in a space group Pbca in a nearly planar structure and the crystal structure of complex shows a Co III N6 coordination geometry in which each L shows N, N, N-donor binding modes . Solution magnetic susceptibility measurement of [CoL2 ]ClO4 by modified Evan's method confirms the low spin diamagnetic nature of the cobalt(III) complex. New compounds were screened for their antibacterial studies against gram positive bacteria including Staphylococcus aureus, Streptococcus faecalis and Bacillus subtilis and gram-negative bacteria including Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Klebsiella pneumonia and Proteus vulgaris . Both the compounds show very stronger growth inhibition activity against gram negative bacteria than gram positive bacteria. Present study shows that HL⋅Br has maximum antibacterial activity against E. coli (25 ± 0.2 mm) and S. typhi (28 ± 0.7 mm) at an MIC of 200 µg/mL and 50 µg/mL respectively, showing greater MIC values than the standard antibiotic ciprofloxacin (8 µg/mL against E. coli and 10 µg/mL against S. typhi ).