A pyrimidine thiolate Rh(i) complex: structure, bonding and one-dimensional interactions in solid and in solution

Abstract

The reaction of [Rh(µ-Cl)(COD)]₂ with 4,6-dimethyl-pyrimidinethiolate (Me₂-pymt) and subsequent substitution of COD by CO yields [Rh(Me₂-pymt)(CO)₂]. The stacking pattern found in this compound is in contradiction with previously studied comparable square-planar complexes of type d⁸-[M(chelate)(monodentate)₂] in which each ligand has different π-acidic character. A theoretical study of the intermolecular interactions and conformation of the title compound has been carried out, combining semi-empirical band calculations on the real chains and ab initio (MP2 level) calculations on a model dimer. The combination of electronic and steric effects determines the rotation of the successive monomers and the deviation from linearity of the one-dimensional stacks. Its behaviour in solution is also special, developing a blue colour and forming micelles, when adding water to acetone solutions.