Hydrogen bonding effects on coordinated sulfoxides and relative role of intra- and inter-molecular interactions determining the dmso orientation in [RR ' NHOH][fac-RuCl3(dmso)(3)] compounds: a crystallographic and molecular mechanics study

Compounds with hydroxyl ammonium cations, [RR'NHOH][fac-RuCl3(dmso-S)(3)], with R = R' = H (1), R = Me, R' = H (2) and R = R' = Et (3), have been prep ared and structurally characterized by X-ray analyses. The three compounds display chain-like structures, formed by hydrogen bonding between the hydro xyl ammonium cations and the chlorine and oxygen atoms of the ruthenium ani on, H-bonding involving the dmso oxygen atoms causes a lengthening of the S -O bonds. The comparison of the solid state structures with results of Mole cular Mechanics calculations show that the arrangement of the fac-dmso-S li gands is not determined by H-bonding or packing effects, but from intramole cular steric and electrostatic interactions. These give rise to hindered ro tation about the Ru-S bonds. (C) 2000 Elsevier Science B.V. All rights rese rved.