The preparation and characterisation of salts of cis-bis(2,2′-bipyridine)-chloro(dimethylsulfoxide)-ruthenium(II) and the crystal structure of the perchlorate dihydrate. Precursors for DNA-binding ruthenium(II) complexes

The preparation and characterisation of salts of the complex cation cis-bis(2,2′-bipyridine)-chloro(dimethylsulfoxide-S)ruthenium(II), [Ru(bpy)₂Cl(dmso)]⁺, is reported. The complex was prepared by the reaction of 2,2′-bipyridine with RuCl₂ · 3H₂O in dimethylsulfoxide. The value of this complex arises from its ability to react with suitable bidentate ligands particularly those that could act as DNA intercalators. The structure of [Ru(bpy)₂Cl(dmso)][ClO₄]·2H₂O has been determined by single crystal X-ray diffraction. The complex crystallises in space group P1̄ with a=8.205(3), b=10.448(4), c= 16.769(6)Å; α=78.99(3)°, β=77.47(3)°, γ=72.20(3)°, Z=2. The structure was refined by least-squares methods using 4070 observed reflections with 196 variable parameters (final R=0.039).