Photophysical properties and the NO photorelease mechanism of a ruthenium nitrosyl model complex investigated using the CASSCF-in-DFT embedding approach

Abstract

A complete state-averaged active space self-consistent field (SA-CASSCF) calculation by means of the SA-CASSCF(18,14)-in-BP86 Miller–Manby embedding approach was performed to explore the ground and excited electronic states of the trans-[RuCl(NO)(NH₃)₄]²⁺ complex. Insights into the NO photodissociation mechanism and Ru–NO bonding properties are provided. In addition, spin–orbit (SO) interactions were taken into account to describe and characterize the spin-forbidden transitions observed at the low-energy regions of the trans-[RuCl(NO)(NH₃)₄]²⁺ UV-Vis spectrum. The SA-CASSCF(18,14)-in-BP86 electronic spectrum is in great agreement with the experimental data of Schreiner [Schreiner et al., Inorg. Chem., 1972, 11, 880].