Creaven, Bernadette S. and Egan, Denise A. and Kavanagh, Kevin and McCann, Malachy and Mahon, Mary and Noble, Andy and Thati, Bhumika and Walsh, Maureen (2005) Synthesis and antimicrobial activity of copper(II) and silver(I) complexes of hydroxynitrocoumarins: X-ray crystal structures of [Cu(hnc)2(H2O)2] Æ 2H2O and [Ag(hnc)] (hncH = 4-hydroxy-3-nitro-2H-chromen-2-one). Polyhedron, 24 (8). pp. 949-957. ISSN 0277-5387

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Abstract

[Cu(hnc)2(H2O)2] · 2H2O (1) [hncH = 4-hydroxy-3-nitro-2H-chromen-2-one] and [Ag(hnc)] (2) were prepared by deprotonating the hydroxy group of hncH with NaOH and then adding copper(II) chloride dihydrate and silver(I) nitrate, respectively. [Ag(hmnc)] (3) was synthesised in a similar manner [hmncH = 7-hydroxy-8-nitro-3-methyl-2H-chromen-2-one]. The mixed-ligand Ag(I) complex [Ag(phen)2hnc] (4) was prepared by treating silver(I) nitrate with 1,10-phenanthroline (phen) (1:1) and subsequent reaction with a solution containing hncH and NaOH. Molecular structures of 1 and 2 were determined by X-ray crystallography. The asymmetric unit in 1 contains two molecules of water in addition to one molecule of the copper complex. In 2 the asymmetric unit comprises one hnc− ligand moiety bonded in a bidentate fashion to the silver(I) ion with additional interactions from three other coumarin ligands. The geometry is best described as pentagonal bipyramidal. While none of the coumarin-based ligands or the free copper salt showed any significant anti-microbial activity, AgNO3 and its’ phen and coumarin complexes exhibited good anti-microbial activity, particularly against the clinically important methicillin-resistant Staphylococcus aureus (MRSA) bacterium and also demonstrated good activity, comparable to that of the commercial fungicides clortrimazole and ketoconazole, against a clinical isolate of the fungal pathogen Candida albicans.

Item Type:	Article
Keywords:	Coumarin; Copper(II); Silver(I); Anti-microbial; X-ray structure; Candida albicans;
Academic Unit:	Faculty of Science and Engineering > Biology
Item ID:	7576
Identification Number:	https://doi.org/10.1016/j.poly.2005.03.006
Depositing User:	Dr. Kevin Kavanagh
Date Deposited:	26 Oct 2016 13:47
Journal or Publication Title:	Polyhedron
Publisher:	Elsevier
Refereed:	Yes
URI:	http://www.sciencedirect.com
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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