The rise and fall of copper hydride clusters. A snapshot of hexanuclear-to-dodecanuclear expansion

Abstract

Phosphine-supported copper hydrides are prone to aggregation to form various clusters. This study focuses on the synthesis, structural characterization, and reactivity of a novel dodecanuclear copper hydride, (iPrPNHP)4Cu12H12 (iPrPNHP = HN(CH2CH2PiPr2)2). This specific copper hydride species represents a transient cluster on the degradation pathway from (iPrPNHP)3Cu6H6 to Cu(0), iPrPNHP, and H2 as well as a frequently encountered by-product during the reduction of carbonyl compounds with (iPrPNHP)3Cu6H6. These data complement the previous study of cluster expansion from (iPrPNHP)2Cu4H4 to (iPrPNHP)3Cu6H6 and deepen the understanding of how copper clusters grow and decay in solution. The effects of phosphorus substituents on the stability of the copper hydride clusters are also explored.