Self-Assembly and Dynamic Equilibrium of Trinuclear and Tetranuclear Cu(I) Supramolecules Featuring nido -Carborane-Supported N -Heterocyclic Carbene Ligands

作者：Yun-Kang Ren, Yiwen Li, Mei-Juan Liang, Jinhang Ma, Zixuan Niu, Xu‐Qiong Xiao · 发表于：Inorganic Chemistry · 年份：2025 · DOI：10.1021/acs.inorgchem.5c00935 · 被引用次数：7 · 研究领域：Supramolecular Chemistry and Complexes、Organometallic Complex Synthesis and Catalysis、Magnetism in coordination complexes

The self-assembly of metallo-supramolecules has attracted considerable attention in recent decades. These discrete architectures are primarily driven by coordination interactions, typically involving M–N/O (Werner-type) or M–C (organometallic) bonding. However, the use of M–π interactions for constructing these multinuclear complexes remains largely unexplored. In this work, we report the self-assembly of trinuclear and tetranuclear copper(I) complexes driven by a combination of M–π and M–C coordination interactions. These multinuclear Cu(I)–NHC complexes were synthesized from the nido -carborane-supported N -heterocyclic carbene (NHC) precursors and Cu(I) ions. In solution, a dynamic equilibrium between the trinuclear and tetranuclear species was observed, as confirmed by the variable-temperature NMR spectrum. Van’t Hoff analysis revealed that the equilibrium is endothermic (Δ H eq = 53.6 kJ mol –1 ) and entropically driven (Δ S eq = 158 J mol –1 K –1 ). The solid-state structures of both forms were elucidated through single-crystal XRD analysis. Density functional theory calculations showed that the Cu–C NHC bonds in these complexes are relatively weak (∼100 kJ mol –1, approximately one-third of the strength of typical Cu–C NHC bonds). This is attributed to the strong Coulombic attraction between positively charged Cu(I) and negatively charged nido -carborane ligands (M–π interactions), which significantly reduces the bond strength between Cu(I) and neutral NHC moieties (M–...