Theoretical Investigation of Hydrogen‐Bond‐Assisted Tetradentate N4 Copper(I) Chloride and trans‐1,2‐Peroxodicopper Complexes

Abstract

Biological oxygenation catalyzed by copper‐containing enzymes involves a dicopper O2 adduct as the key intermediate. Significant insights were offered by the trans‐1,2‐peroxodicopper intermediates. To understand the activity of the trans‐1,2‐peroxodicopper intermediate in the oxygenation, a series of hydrogen‐bond‐assisted CuI(L)−Cl and trans‐1,2‐peroxodicopper complexes [Cu2−O2]2+ were investigated by DFT computations. A reasonable two‐parameter structure‐activity model (R2=0.8611) and a three‐parameter structure‐activity model (R2=0.8773) for chloride dissociation (ΔG1RXN) were established. The critical intramolecular out‐sphere hydrogen bonds assist the formation of stable trans‐1,2‐peroxodicopper complexes, which overcome the steric hindrances and electrostatic repulsion. An acceptable two‐parameter structure‐activity model (R2=0.7051) for O2 binding (ΔG2RXN) was obtained. The fundamental structure‐activity interpretation of the hydrogen bonding interactions provides an insight into the modelling of trans‐1,2‐peroxodicopper mimics.Critical roles of intramolecular out‐sphere hydrogen bonds in the stabilization of CuI−Cl bonds and in the formation of trans‐1,2‐peroxodicopper complexes are theoretically investigated. Reasonable structure‐activity models for chloride dissociation and O2 binding are established, and the fundamental interpretation of modelling the trans‐1,2‐peroxodicopper mimics is provided.