Dichlorotetrakis(dimethyl sulfoxide) ruthenium(II) describes
coordination compounds with the formula RuCl2(dmso)4, where DMSO is
dimethylsulfoxide. Both cis and trans isomers are known, but the cis isomer is more common. The cis isomer is a yellow, air-stable solid that is soluble in some organic solvents. These
sulfoxide complexes are used in the synthesis of various ruthenium(ii) complexes.[1] They have also attracted attention as possible anti-cancer drugs.
Structure and synthesis
The cis isomer illustrates
linkage isomerism for the
DMSOligand.[2] One of the two dmso ligands that are cis to both chloride ligands is O-bonded while the other three dmso ligands are S-bonded. In the trans isomer, which is also yellow, all four dmso ligands are S-bonded. The cis isomer is formed thermally, and the trans isomer is obtained by UV-irradiation of the cis isomer.[3]
cis isomer
trans isomer
The complexes were first prepared in 1971 by heating DMSO solutions of
ruthenium trichloride under
hydrogen atmosphere.[4] Modern procedures has been developed which avoids hydrogen gas, either using ascorbic acid or refluxing DMSO to reduce the ruthenium.[3][5][6]
Potential applications
RuCl2(dmso)4 was identified as a potential anticancer agent in the early 1980s.[7] Continued research[8][9] has led to the development of several related dmso-containing ruthenium compounds, some of which have undergone early-stage clinical trials.[10]
^Sava, Gianni; Giraldi, Tullio; Mestroni, Giovanni; Zassinovich, Grazia (July 1983). "Antitumor effects of rhodium(I), iridium(I) and ruthenium(II) complexes in comparison with cis-dichlorodiammino platinum(II) in mice bearing Lewis lung carcinoma". Chemico-Biological Interactions. 45 (1): 1–6.
doi:
10.1016/0009-2797(83)90037-6.
PMID6683595.
^Coluccia, Mauro; Sava, Gianni; Loseto, Francesco; Nassi, Anna; Boccarelli, Angela; Giordano, Domenico; Alessio, Enzo; Mestroni, Giovanni (January 1993). "Anti-leukaemic action of RuCl2(DMSO)4 isomers and prevention of brain involvement on P388 leukaemia and on subline". European Journal of Cancer. 29 (13): 1873–1879.
doi:
10.1016/0959-8049(93)90541-M.
PMID8260245.
^Bratsos, I; Serli, B; Zangranko, E; Katsaros, N; Alessio, E. (2007). "Replacement of chlorides with dicarboxylate ligands in anticancer active Ru(II)-DMSO compounds: A new strategy that might lead to improved activity". Inorg. Chem.46 (3): 975–992.
doi:
10.1021/ic0613964.
PMID17257042.
^Enzo Alessio, Bentham Science Publisher; Giovanni Mestroni, Bentham Science Publisher; Alberta Bergamo, Bentham Science Publisher; Gianni Sava, Bentham Science Publisher (1 November 2004). "Ruthenium Antimetastatic Agents". Current Topics in Medicinal Chemistry. 4 (15): 1525–1535.
doi:
10.2174/1568026043387421.
PMID15579094.