DFT analysis of the linkage isomerism in penta(ammine)ruthenium(II/III) complexes of benzotriazole: Natural bond orbital method approach and a comprehensive energy decomposition analysis

Abstract

Penta(ammine)ruthenium benzotriazole complexes [RuII/III(NH3)5bta]+/2+ and [RuII/III(NH3)5btaH]2+/3+ (bta and btaH are the deprotonated and neutral form of the triazole ligand, respectively) can exhibit two linkage isomers κN1 and κN2. This system was investigated by density functional theory natural bond orbitals analysis and Su‐Li energy decomposition analysis. Steric, electrostatic, exchange, repulsion, polarization, and dispersion energy components of the total metal–ligand interaction were quantitatively evaluated, and revealed that the overall metal‐triazole ligand is comprised of donor–acceptor interactions like σ‐donation and π‐back‐donation, which favors a specific isomer depending on the oxidation state of the ruthenium and the charge of the ligand. Further, activation energies (ΔG‡) for linkage isomerization reactions were calculated. Results were correlated with experimental chemical–electrochemical data and two plausible mechanisms are discussed. © 2019 Wiley Periodicals, Inc.

Generalized Kohn‐Sham energy decomposition analysis and its applications

“…Metal‐ligand interactions play important roles in nanocrystals, molecular recognition, drug design, metalloprotein chemistry, and so on. Both GKS‐EDA and LMO‐EDA have been employed in the interpretations of various metal‐ligand interactions, which are not trivial tasks due to the inherent complexity of the arrangement of electrons in d‐ and f‐metal‐atom orbitals coupled with the various ligands.…”