Bidentate Sulfoxide Complexes of Ruthenium(II) and Their Preliminary Biological Assessment in Vitro

The complexes trans -RuCl 2 (BMSE) 2 ( 1 ), cis -RuCl 2 (BESE) 2 ( 2 ), trans -RuCl 2 (BPSE) 2 ( 3 ), and cis -RuCl 2 (BMSP) 2 ( 4 ) have been synthesized and characterized, including X-ray analyses [BMSE = 1,2-bis(methylsulfinyl)ethane, BESE = 1,2-bis(ethylsulfinyl)ethane, BPSE = 1,2-bis(propylsulfinyl)ethane, and BMSP = 1,3-bis(methylsulfinyl)propane]. Crystal data are as follows: 1 ·H 2 O, triclinic, P 1, a = 8.863(1) Å, b = 14.462(3) Å, c = 7.543(1) Å, α = 103.39(1)°, β = 113.31(1)°, γ = 77.23(1)°, Z = 2; 2 ·MeOH, triclinic, P 1̄, a = 14.858(2) Å, b = 16.732(3) Å, c = 10.609(2) Å, α = 105.14(2)°, β = 93.34(2)°, γ = 115.91(1)°, Z = 4; 3, orthorhombic, Aba 2, a = 14.894(1) Å, b = 7.501(1) Å, c = 21.911(2) Å, Z = 4; 4, orthorhombic, Pcab, a = 15.257(3) Å, b = 18.138(2) Å, c = 13.395(2) Å, Z = 8. The structures were solved by the Patterson method and were refined by full-matrix least-squares procedures to R = 0.026, 0.026, 0.029, and 0.031 for 10461, 8952, 1594, and 5694 reflections with I > 3σ( I ), for 1 − 4, respectively. Preliminary in vitro experiments with Chinese hamster ovary cells indicate that the trans -complexes accumulate in the cells and bind to DNA to a greater degree than the cis -complexes.