Understanding How Pauli-repulsion is Decisive in the Aggregation of PNNP Copper Hydride Complexes

Copper(I) hydride complexes often exhibit diverse aggregation behavior that can profoundly influence their structure and reactivity. In this study, we investigate a series of dicopper hydride complexes supported by PNNP expanded pincer ligands that vary in both aggregation and ligand protonation state. Using a combined experimental and computational approach, we examine how these properties correlate and identify key structural and electronic factors that govern aggregation. Our results reveal a key role for electrostatic effects, but show that Pauli repulsion plays the decisive role in preventing aggregation.