Understanding the fate of electronically excited states by quantum chemical calculations

Abstract

The electronically excited states of transition metal complexes are classified into inter-configurational and intra-configurational metal-centered, ligand-centered, and charge transfer states. Different (de)localization of electron density in different types of excitations results in different geometry distortions. We use quantum mechanical calculations within the time-dependent density functional theory (TD-DFT) framework to describe and characterize the excited states of transition-metal complexes. From the shape of potential energy curves, we elucidate their fate. Examples of our work on Pt(PF_3)_4, Cr(CO)_6, Fe(CO)_5, and Cr(bpy)_3^3+ will illustrate the differences between the fate of different types of excited states. The main aim of our work is to get chemical insight and control of metal-ligand bonding.