118541-58-5

Upstream product

• 72904-46-2 trans-dibromotetrakis(dimethyl sulfoxide)ruthenium(II) 

Downstream Products

• 133982-76-0 {RuBr₂(AsPh₃)2(CS)(Me₂SO)} 
• 133982-77-1 {RuBr₂(CS)(triphenylphosphine)3} 
• 52538-89-3 {RuBr₂(CO)(PPh₃)2(Me₂SO)} 
• 15555-76-7 {RuBr₂(triphenylphosphine)4} 
• 133982-74-8 {RuBr₂(OPPh₃)3} 
• 133982-75-9 {RuBr₂(Me₂SO)2(AsPh₃)2} 

Relevant academic research and scientific papers

cis- and trans-Dihalotetrakis(dimethyl sulfoxide) ruthenium (II) complexes (RuX2(DMSO)4; X = Cl, Br): Synthesis, structure, and antitumor activity

The chemistry of halogen-dimethyl sulfoxide-ruthenium(II) complexes with the general formula RuX2(DMSO)4 (X = Cl, Br) is reported. In particular the synthesis and X-ray structure of trans-RuCl2(DMSO)4 and cis-RuBr2(DMSO)4 are described and compared with those of the already known cis-RuCl2(DMSO)4 and trans-RuBr2(DMSO)4. The structure of a new crystal form of cis-RuCl2(DMSO)4 is also reported. Crystal data: for trans-RuCl2(DMSO)4, tetragonal, I4/m, a = 9.121 (3) ?, c = 11.167 (4) ?, Z = 2, R = 0.040; for cis-RuBr2(DMSO)4, monoclinic, P21/n, a = 8.547 (3) ?, b = 27.873 (4) ?, c = 8.637 (2) ?, β = 115.85 (3)°, Z = 4, R = 0.040; for cis-RuCl2(DMSO)4, monoclinic, P21/n, a = 8.417 (2) ?, b = 27.695 (4) ?, c = 8.598 (2) ?, β = 116.88 (3)°, Z = 4, R = 0.033. While the cis isomers are thermodynamically more stable and form from the trans species, a photochemically driven cis to trans isomerization reaction is observed in dimethyl sulfoxide solution. Kinetic parameters for the thermal trans to cis isomerization reactions for trans-RuCl2(DMSO)4 and trans-RuBr2(DMSO)4, respectively, are k = 2.58 × 10-6 s-1 at 25°C, ΔH? = 128 ± 2 kJ·mol-1, and ΔS? = 110 ± 5 J·mol-1·K-1 and k = 1.25 × 10-5 s-1 at 25°C, ΔH? = 114 ± 5 kJ·mol-1, and ΔS? = 79 ± 18 J·mol-1K-1. In chloroform solution the complexes, and in particular the trans isomers, tend to release a dimethyl sulfoxide molecule to give pentacoordinated Ru(II) complexes. However, in aqueous solution, while the cis complexes immediately release one DMSO, the trans ones release two. In both cases, this step is followed by the slow dissociation of a halide ion. For the chloro derivatives the dissociation is completely inhibited at physiological chloride concentrations. Preliminary results from pharmacological tests show that trans-RuCl2(DMSO)4 is more active than the cis isomer against Lewis lung carcinoma, a metastasizing murine tumor. A remarkable dependence of activity on the halogen nature (Cl > Br) is also observed.