SYNTHESIS AND PROPERTIES OF NEW DNA CLEAVAGE AGENTS BASED ON OXORUTHENIUM(IV)

New aquaruthenium(II) reagents that are capable of being oxidized to hydroxoruthenium(III) and oxoruthenium-(IV) have been prepared. Complexes based on Ru(tpy)(L)OH22+ (L = eta2-tpt, phen, dppz, tmen; tpy = 2,2':6',2''-terpyridine, tpt = 2,4,6-tripyridyltriazine, phen = 1,10-phenanthroline, dppz = dipyridophenazine, and tmen = N,N,N',N'-tetramethylethylenediamine) have been prepared and can all be reversibly oxidized to their Ru(IV)O forms, which are component DNA cleavage agents, as is Ru(phen)2(py)02+. In addition to Ru(tpy)(eta2-tpt)OH22+, the eta3 Complex of tpt, Ru(tpy)(eta3-tpt)2+, can also be prepared under similar conditions. In the presence of Ag+ ion, a novel Ru2Ag complex can be isolated and has been crystallographically characterized. The complex [Ru(tpy)-(eta-tpt)](ClO4)2.0.5AgClO4.0.5H2O crystallizes in the monoclinic space group A2/A with a = 14.723 (5) angstrom, b = 26.061 (6) angstrom, c = 22.148 (6) angstrom, beta = 106.33 (3)-degrees, V = 8155 (5) angstrom3, Z = 4, R = 0.0807, and R(w) = 0. 1 156 for 2923 reflections with I greater-than-or-equal-to 2sigma(I). The Ru(tpy)OH22+ unit can also be attached to the tmen-AO+ ligand, where a N,N',N'trimethylethylenediamine function is appended via a (CH2)6 linker to the acridine orange intercalator. The Ru( tpy)(tmen-AO)OH23+ Complex is an effective cleavage agent, but only when oxidation is performed on the complex prebound to DNA. In homogeneous solution, electrochemically reversible access of only the Ru(III)OH form is possible, probably because of oxidation of the polymethylene linker.