Intramolecular rearrangements guided by adaptive coordination-driven reactions toward highly luminescent polynuclear Cu(i) assemblies

Abstract

Adaptive coordination-driven supramolecular chemistry based on conformationally flexible pre-organized luminescent Cu(I) precursors paves the way to the ready formation of an intricate supramolecular scaffold possessing intrinsic luminescence properties. A formal ring extension of a tetrametallic Cu(I) metallacycle bearing Thermally Activated Delayed Fluorescence (TADF) properties can thus be carried out, affording a new hexametallic Cu(I) metallacycle 1 bearing modulated solid-state TADF properties. Attempts to adapt this ring extension process to the formation of targeted heterometallic Au₂Cu₄ and Pt₂Cu₈ assemblies led to the unexpected and ready formation of the Au₂Cu₁₀ and Pt₄Cu₁₁ derivatives 2 and 3, respectively. These outcomes strengthen the scope and perspectives of adaptive coordination-driven supramolecular chemistry compared to those of conventional coordination-driven supramolecular chemistry. Indeed, it guides concerted intramolecular fragmentation and redistribution of the particular building blocks used, affording selectively supramolecular scaffolds of higher nuclearity and complexity. The study of the solid-state photophysical properties of the assemblies 2 and 3 highlights enhanced and original behaviors, in which the heavy metal spin–orbit coupling values significantly influence the relaxation processes centered on the Cu(I) metal centers.