SYNTHESIS OF BINUCLEAR PLATINUM(II) ORGANOMETALLIC COMPLEXES AS POTENTIAL CROSS-LINKING REAGENTS

A series of new organometallic binuclear platinum(II) complexes of the type [{PtMeCl(Me2SO)}(2)(mu-N-N)] (N-N = H2N(CH2)(n)NH2 with n = 4, 6 , 8, 10, 12; 4,4'-bipyridyl and 1,2-bis(4'-pyridyl) ethane) was synthe sized and characterized through elemental analysis, H-1 and C-13 NMR s pectroscopy. The interaction of the mononuclear model complex [PtMeCl( Me2SO) ((BuNH2)-N-n)] and of the binuclear complex [{PtMeCl(Me2SO)}(2) (mu-H2N(CH2)(6)NH2] with different nucleosides was investigated by H-1 NMR spectroscopy, revealing a binding preference toward N-7 position in inosine and guanosine and N-3 in cytidine. Thymidine and uridine ar e not reactive under the same experimental conditions. Gel electrophor esis experiments indicated that the binuclear complexes containing bri dging diamines are able to induce significant conformational changes i n the supercoiled form of pUC19 plasmid. (C) 1998 Elsevier Science S.A . All rights reserved.