Solvent- and metal-gated coordination diversity in a dynamic aminal ligand

Abstract

Within the broad landscape of dynamic covalent chemistry (DCC), the coordination chemistry of primary-amine-based aminals has received comparatively little systematic investigation. Here we demonstrate that a primary-amine-based dynamic covalent aminal (L^A2) can serve as an adaptive scaffold for coordination chemistry diversity, where solvent and metal ion choice govern distinct outcomes. Coordination stabilizes otherwise transient ligand forms and directs divergent pathways: Co(III) stabilizes hemiaminalates in methanol, with [Co(L^O2)₂](ClO₄) exhibiting fluxional behavior, and templates macrocyclization in acetonitrile to yield [Co(L^M)](ClO₄)₃; Cu(II) affords hemiaminal and hemiaminal ether complexes, and Fe(III) promotes pyridinium dimerization to give cis-[(L^I2)₂](ClO₄). These findings establish that dynamic ligands can actively generate structural diversity in metal complexes, opening new directions for adaptive ligand design and functional coordination architectures.