Transition metal coordination compounds with redox-active (non-innocent ) ligands possess flexible valence electronic structure susceptible to low energy barrier intramolecular electron transfers within the molecule and providing for the formation of electronic isomers with migrating paramagnetic centers. Magnetic behaviour of these complexes, kinetic and thermodynamic parameters of rearrangements of the electromers are highly sensitive with respect to even tiny structural modifications and effects of solvation and nonspecific intermolecular interactions. The proper understanding and interpretation of the peculiar properties and reactivity of these compounds must, obviously, be based on the application of methods of modern quantum chemistry, which is the goal of the present report largely addressed to chemists employing quantum chemical calculations for prediction of novel and description of experimentally studied transition metal complexes with redox-active ligands. A distinctive feature of the adopted approach is that careful attention is given to the precise account taken for of all structural peculiarities of the molecular systems, underestimation of which in calculations of model systems often leads to wrong results and may disorient experimentalists.
Versatility of the DFT method for the studies of magnetic, geometry and energetic properties of transition metal complexes with redox-active ligands is considered . Particular attention is given to the correct choice of model compounds and methodology of the calculations.
Acknowledgments: This work was supported by Russian Science Foundation (14-13-00573).