tailieunhanh - Dinuclear complexes of copper and silver with quinine

The following silver and copper complexes in which quinine is coordinated via the two possible donor atoms was prepared and characterized. Coordination of quinine via the hydroxyl oxygen and quinoline nitrogen is observed in C20H25N2O2Cu2(SO4) and C20H25N2O2Ag2(SO4). The existence of the proton at the coordinated hydroxyl oxygen is also observed in these complexes. The coordination mode and the conformation of quinine can be derived from IR and Raman spectra and by using NMR techniques. | Journal of Chemistry Vol. 45 2 P. 255 - 259 2007 DINUCLEAR COMPLEXES OF COPPER AND SILVER WITH QUININE Received 14 Sep. 2006 NGUYEN THANH HONG BUI TRONG DAT Institute of Chemical Technology Vietnames Academy of Science and Technology SUMMARY The following silver and copper complexes in which quinine is coordinated via the two possible donor atoms was prepared and characterized. Coordination of quinine via the hydroxyl oxygen and quinoline nitrogen is observed in C20H25N2O2Cu2 SO4 and C20H25N2O2Ag2 SO4 . The existence of the proton at the coordinated hydroxyl oxygen is also observed in these complexes. The coordination mode and the conformation of quinine can be derived from IR and Raman spectra and by using NMR techniques. I - INTRODUCTION II - EXPERIMENTAL Quinine - cinchona alkaloid - is a widely used antimalaria drug and its derivatives are applied as optically active auxiliaries in asymetriric synthesis 1 - 6 . In 1996 the Beck s group 7 used the Lewis acids q5-C5H5 Ph3P OC Ru ClAuSMe2 and the chlorine-bridged complexes q5-C5Me5 MCl2 2 M Rh Ir and q6-p-cymene RuCl2 2 for the complexation of quinine and obtained the coordination on tertiary N and hydroxyl O of quinine cation. Later in 1999 the same Beck s group 8 has synthesized quinine complexes using all four potential donor sites of quinine hydroxyl O tertiary N and pyridine N atoms olefinic C C bond . In other work 9 the Fe-O Zn-O and Ce-O bonds were evidenced to form via the quinine hydroxyl oxygen with a preservation of hydrogen bond. In this paper we report on the synthesis of quinine complexes with silver and copper using the pyridine N atom and the hydroxyl O atom with a preservation of the quinine hydrogen bond. - Quinine C20H24N2O2 was used as supplied Merck with the structural formula 1 . 1 - IR Bruker-vector 22 spectrophotometer. -Raman Micro-Raman LABRAM-1B. - All NMR measurements Bruker AVANCE 500 MHz the proton frequency is MHz while the carbon frequency is at MHz. Carbon .