Dalton Trans 2006 Jun 7; 2542-50 (Read article online)

Abu-Youssef MA, Langer V, Ohrström L

The synthesis and low temperature crystal structures of [Ag(quinoxaline)](n)(NO(3))(n), , [Ag(2,5-dimethylpyrazine)(NO(3))](n), and [Ag(4)(3-aminopyridine)(4)(NO(3))(4)](n) are presented. The quinoxaline compound forms a 1D coordination polymer with the characteristic linear 2-coordination figure of silver(i), the N-Ag-N angle being 164.2(1) degrees , and only weak silver-nitrate interactions. In addition there is an interaction giving pairs of parallel chains as the main structural theme. The 2,5-dimethylpyrazine compound has approximately trigonal-planar coordination, also binding one nitrate at the relatively short Ag-O distances 2.444(3) A and 2.484(3) A, respectively, for the two crystallographically different silver atoms. This also results in a 1D coordination polymer that, despite the large differences in the Ag(i) coordination environment, is isostructural with . [Ag(4)(3-aminopyridine)(4)(NO(3))(4)](n) forms a 2D coordination polymer by bridging nitrate ions. The antimicrobial activity of , and also of [Ag(3)(2-aminopyridine)(4)](NO(3))(3), was screened for 13 different pathogens and substantial activity was shown for against Escherichia coli and Pseudomonas aeruginosa (MIC 4 microg cm(-3)) and somewhat lower activity was registered against Sarcina lutea and Salmonella typhi for , Bordetella bronchiseptica for , Salmonella typhi and Pseudomonas aeruginosa for , and Escherichia coli and Shigella sonnie for (MIC 8 microg cm(-3)). Only low activity was shown against the yeast Candida albicans for , and whereas no activity against this pathogen was registered for .