Substitution of chloride by nitrosyl ligand in a scorpionate ruthenium(III) compound: A theoretical study

A theoretical study of the ruthenium(III) complex [RuCl2(pz2CHSO3)(en)] and of its nitrosyl-substituted product [Ru(NO)Cl(pz2CHSO3)(en)]+ is presented, based on density functional calculations. Several isomers of each compound differing in the position of the anionic tail of a bis(3,4-dimethyl-1-yl)methanesulfonate scorpionate ligand, pz2CHSO3−, relative to the monodentate ligands have been optimized. A two-step mechanism is proposed for the ligand substitution reaction that is consistent with the computational results and the weak coordination of the sulfonate group.