Intermolecular Interactions between Thiocyanato Ligands in Metal Complexes

Herein, we have carried out a combined structural and computational analysis of short contacts between thiocyanato ligands in transition-metal complexes. Because of the particular electron density distribution of thiocyanato, this ligand is able to engage in several interaction topologies involving sulfur, carbon, and nitrogen atoms. A comprehensive computational study of such short contacts has allowed us to unveil whether they are attractive or repulsive. The calculation of the interaction energies in a series of dimers helped us to calibrate the strength of the different interaction geometries. Furthermore, inspection of the topology of the electron density by means of the quantum theory of atoms in molecules (QTAIM) and noncovalent index (NCI) calculations as well as natural bond orbital (NBO) and electron localization function (ELF) analyses have been performed to shed light on the nature of the interactions.