A series of new complexes with mixed ligands of the type RuLm(DMSO)nCl3·xH2O ((1) L: oxolinic acid (oxo), m = 1, n = 0, x = 4; (2) L: pipemidic acid (pip), m = 2, n = 1, x = 2; (3) L: enoxacin (enx), m = 2, n = 1, x = 0; (4) L: levofloxacin (levofx), m = 2, n = 2, x = 8; DMSO: dimethylsulfoxide) were synthesized and characterized by chemical analysis, IR and electronic data. Except oxolinic
acid that behaves as bidentate, the other ligands (quinolone derivatives and DMSO) act as unidentate. Electronic spectra are
in accordance with an octahedral stereochemistry. The thermal analysis (TG, DTA) in synthetic air flow elucidated the composition
and also the number and nature of both water and DMSO molecules. The TG curves show 3–5 well-separated thermal steps. The
first corresponds to the water and/or DMSO loss at lower temperatures followed either by quinolone thermal decomposition or
pyrolisys at higher temperatures. The final product is ruthenium(IV) oxide.