Synthesis, characterization, and antibacterial activities of copper(I) bromide complexes of thioureas: X-ray structure of [Cu(Metu)4]Br

Abstract

Copper(I) complexes of thioureas having the general formulae [CuL nBr] and [CuLn]Br [where, n = 1 - 4 and L = thiourea (Tu), N-methylthiourea (Metu), N-ethylthiourea (Ettu), N,N′-dipropylthiourea (Dprtu), N,N′-dibutylthiourea (Dbtu) or N,N′-diphenylthiourea (Dphtu)] were prepared and characterized by elemental analysis, IR, and NMR (1H and 13C) spectroscopy. The crystal structure of one of them, [Cu(Metu)4]Br (1), was determined by X-ray crystallography. The X-ray structure of 1 describes a tetrahedral geometry around copper(I) with all Metu ligands binding through sulfur atoms. An upfield shift in the 13C NMR and downfield shift in the 1H NMR spectra are consistent with the thione coordination to copper(I). Antimicrobial activities of the complexes were evaluated by the minimum inhibitory concentration method. The results showed that only [Cu(Ettu)3Br] was effective in inhibiting the growth of all the tested organisms (gram-positive, gram-negative bacteria, and Candida sp.), while the other complexes were not effective against all the organisms. © 2011 Springer Science+Business Media B.V.