Energy Decomposition Analysis of Metal-Ligand Bonding inTransition Metal Complexess with Carbenes and Ylides Ligands: Significanceof Electrostatic Interactions in Bond Analysis ‡

This work describes a pedagogical approach to understanding chemical bonding byemphasizing the significance of electrostatic interactions in Metal-Ligand Bonding, particularlyin Transition Metal Complexes with Carbenes and Ylides Ligands. Energy DecompositionAnalysis (EDA) is a powerful method for quantitatively interpreting chemical bonds in terms ofthree major components. The instantaneous interaction energy ΔEint between two fragments Mand L in a molecule M←L is partitioned into three terms: (۱) the electrostatic interaction ΔEelstatbetween the fragments, (۲) the repulsive exchange, Pauli interaction ΔEPauli between electrons ofthe two fragments with the same spin, and (۳) the orbital (covalent) interaction ΔEorb, whicharises from orbital relaxation and orbital mixing between the fragments. The latter term can befurther decomposed into contributions from orbitals with different symmetries, enabling thedistinction between σ, π, and δ bonding The results demonstrate that the EDA terms can beinterpreted in a chemically meaningful way, thus establishing a connection between quantumchemical calculations and heuristic bonding models of traditional chemistry. The nature of theL→M bond in the complexes was analyzed using NBO, AIM, EDA, and ETS-NOCVmethods.The findings confirm that the electrostatic interaction term, ΔEelstat, becomes notablyhigher and contributes significantly to the orbital interactions in the studied complexes