Ruthenium(III and II) β-diketonate complexes containing imidazoles

The Ru-III complexes, [Ru(acac)(2)L-2] Tf, and the Ru-II complexes, Ru(hfac)(2)L-2, have been synthesized and characterized; acac = acetylacetonate, hfac = 1,1,1,5,5,5-hexafluoroacetonate, Tf = triflate, and L = imidazole (Im) or a substituted imidazole (NMeIm, 2MeIm, 4/5MeIm, 2NO(2)Im); other nitroimidazoles, named metronidazole, etanidazole, and EF5 (a pentafluorinated derivative of etanidazole) were also used. Cis-isomers of the Ru complexes were usually formed, but some trans-isomers were also isolated. Characterization methods include NMR, UV/Vis, and MS spectroscopies, and CV data; X-ray crystallographic data were obtained for the cis-[Ru(acac)(2)L-2] Tf complexes (L = Im, NMeIm, 2MeIm, and 5MeIm). Interest in these complexes stems from their potential antiproliferatory activity, and use of the nitroimidazole species as radiosensitizers. More incidentally synthesized were cis-[Ru(acac)(2)L(MeCN)] Tf (L = Im, 2MeIm), cis-Ru(hfac)(2)Im(MeCN), and [Ru(hfac)(NMeIm)(4)]PF6. (C) 2017 Elsevier B.V. All rights reserved.