Synthesis and crystal structure of new Ru(III)-sulfoxide complexes containing a planar N-ligand: mer,cis-RuCl3(1Me-Im)(2)(S-DMSO) and [4Et-PyH][trans-RuCl4(4Et-Py)(S-DMSO)]

The title compounds, mer-trichloro-cis-bis(1-methylimidazole) dimethyl sulfoxideruthenium(III) (1) and 4-ethylpyridinium trans-(4-ethylpyridine) (dimethyl sulfoxide) tetrachlororuthenate(III) (2) have been synthesized and structurally characterized. Crystals of 1 [RuCl3(C4H6N2)(2)(C2H6OS)]. 0.5(C3H6O) are monoclinic, space group P2/c with a=16.836(9), b=8.646(3), c=14.017(7) Angstrom, beta=110.19(2)degrees, Z=4. Crystals of 2 [RuCl4(C7H9N)(C2H6OS)][C7H10N] are monoclinic, space group P2(1)/n with a=7.996(1), b=11.670(1), c=23.979(3) Angstrom, beta=98.39(1)degrees, Z=4. The sulfoxide ligands are S-bonded and trans to the N-planar ligands in both Ru(III) complexes. The two 1Me-Im ligands in 1 are cis to each other and the arrangement is such that its B/B' interbase dihedral angle is 65.6 degrees. B/RuI4 and B'/RuL(4) dihedral angles are 26.8 and 66.8 degrees, respectively. The 4Et-Py plane in 2 bisects the Cl-Ru-Cl bond angles. The conformation of the planar N-ligand observed in the X-ray structures is discussed in terms of an interaction between the ligands.