Syntheses, structures and antimicrobial activities of water-soluble silver(I)-oxygen bonding complexes with chiral and racemic camphanic acid (Hca) ligands.
Water-soluble, relatively light-stable, chiral and achiral silver(I) complexes [[Ag(2)(ca)(2)]](n) and [[Ag(2)(ca)(2)(Hca)(2)]](n)(R- and S-Hca =(1R,4S)- and (1S,4R)-4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptane-1-carboxylic acid, respectively) prepared from the reaction of Ag(2)O with chiral and racemic Hca in 1:2 and 1:4 molar ratios were characterized by elemental analysis, TG/DTA, FTIR, and solution ((1)H, (13)C and (109)Ag) and solid-state ((13)C) NMR spectroscopy. Crystallography revealed that unique 2(1) helical polymer and zigzag structures were formed on self-assembly of the dimeric units in the crystals of [[Ag(2)(S-ca)(2)]](n) and three [[Ag(2)(ca)(2)(Hca)(2)]](n). In the crystal of [[Ag(2)(S-ca)(2)]](n) two 2(1) helices and a loop were observed in the stair-like polymer structure, whereas zigzag and a loop were seen in the crystals of three [[Ag(2)(ca)(2)(Hca)(2)]](n). Carbon NMR spectra in the solid state and in D(2)O indicated that these polymeric structures were loosely bound and fast ligand-exchange reactions took place in aqueous solution. The complexes, [[Ag(2)(ca)(2)]](n) and [[Ag(2)(ca)(2)(Hca)(2)]](n), showed a wide spectrum of effective antimicrobial activity as anticipated for weak silver(i)-O bonding complexes. Similar antimicrobial activity of [[Ag(2)(ca)(2)]](n) and [[Ag(2)(ca)(2)(Hca)(2)]](n) against selected microorganisms suggested that ligand exchangeability played an important role as well as the coordination geometry of the silver(i) ion.
Kasuga
Noriko Chikaraishi
NC
Department of Materials Science, Faculty of Science, Kanagawa University, Japan.
Sugie
Akiyoshi
A
Nomiya
Kenji
K
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D001952:Bridged-Ring Compounds / Q000737:chemistry*; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D007783:Lactones / Q000737:chemistry*; D008024:Ligands; D008826:Microbial Sensitivity Tests; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D010100:Oxygen / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D012995:Solubility; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry
D000900:Anti-Bacterial Agents; D001952:Bridged-Ring Compounds; D007783:Lactones; D008024:Ligands; D009942:Organometallic Compounds; C500772:camphanic acid; D014867:Water; D012834:Silver; D010100:Oxygen