Dichlorotetrakis(dimethyl sulfoxide) ruthenium(II) describes

coordination compound A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...

s 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 compounds have attracted attention as possible anti-cancer drugs.

Structure and synthesis

The ''cis'' isomer illustrates

linkage isomer In chemistry, linkage isomerism or ambidentate isomerism is a form of isomerism in which certain coordination compounds have the same composition but differ in their metal atom's connectivity to a ligand. Typical ligands that give rise to linkage ...

ism for the DMSO

ligand In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electr ...

. 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. The complexes were first prepared by heating DMSO solutions of ruthenium trichloride under

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...

atmosphere. An alternative procedure has been developed which avoids hydrogen gas.

Potential applications

RuCl₂(dmso)₄ was identified as a potential anticancer agent in the early 1980s. Continued research has led to the development of several related dmso-containing ruthenium compounds, some of which have undergone early-stage clinical trials.

References

{{Ruthenium compounds Coordination complexes Ruthenium complexes Chloro complexes Sulfoxides Ruthenium(II) compounds