Synthesis, theoretical calculations and antimicrobial studies of copper(I) complexes of cysteamine, cysteine and 2-mercaptonicotinic acid. (8th January 2015)

• Record Type: Journal Article
• Authors: Ahmad, Saeed; Espinosa, Arturo; Ahmad, Tayyaba; Sohail, Manzar; Isab, Anvarhusein A.; Saleem, Muhammad; Hameed, Abdul; Monim-ul-Mehboob, Muhammad; Heras, Édgar de las
• Is Part Of: Polyhedron. Volume 85(2015)
• Page Start: 239
• Page End: 245
• Publication Date: 2015-01-08
• Subjects: Copper(I) complexes -- Cuprophilicity -- Thiols -- Theoretical calculations -- Antimicrobial activity; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2014.08.029
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Three new Cu(I)-thiol complexes of cysteamine, cysteine and 2-mercaptonicotinic acid were prepared. According to DFT calculations they show dimeric structures with differently distorted Cu2 ( μ -X)2 cores (X: Cl, I) and displaying short cuprophilic Cu⋯Cu contacts. An additional thiolate-Cu(I) derivative also shows dimeric structure with two antiparallel linearly arranged N–Cu–S moieties. Abstract: Four new copper(I) complexes, [Cu(Cym-H)Cl] (1 ), [Cu(Cys-H)Cl] (2 ), [Cu(Mnt-H)I] (3 ) and [Cu(Mnt)] (4 ) (Cym-H = cysteamine, Cys-H = cysteine and Mnt-H = 2-mercaptonicotinic acid) were prepared and characterized by elemental analysis, IR, 1 H & 13 C NMR spectroscopy and thermal analysis. The absence of S–H vibrations in the IR spectra suggests that the coordination of thiolates to copper(I) occurs through the sulfur atom. In 13 C NMR spectra of3 and4, each resonance splits into three and two resonances respectively, indicating the presence of several species in solution. DFT calculations for1 –4 predicted predominant occurrence of most stable dimers in solution, some of them exhibiting cuprophilic interactions. The electrochemical properties of complexes in DMSO were studied by cyclic voltammetry. Antimicrobial activities were evaluated by minimum inhibitory concentration and complexes1 –4 exhibited significant activities against gram-negative bacteria ( Escherichia coli, Pseudomonas aeruginosa ), while moderate activities were observed (except in case of3 ) against molds ( Aspergillus niger, Penicillium citrinum ) and yeasts ( Candida albicans, Saccharomyces cerevisiae ).