Carboxylate positional isomerism in metallacycles governs hierarchical assembly pathways

Positional isomerism plays a pivotal role in governing the assembly pathways of hierarchical architectures by modulating both the thermodynamic landscape and kinetic trajectories through precise spatial control of the constituent units, ultimately dictating the assembly efficacy and structural outcomes. Elucidating the underlying selectivity mechanisms of such isomerism offers fundamental insights into the rational design of advanced functional materials with tailored properties. Our findings reveal that isomeric variations in metal-organic cycles (MOCs) at the molecular scale trigger a cascade of structural effects-reconfiguring noncovalent interaction networks (particularly hydrogen bonding), diverting hierarchical assembly pathways, and ultimately generating distinct mesoscale architectures (extralong fibers and wide ribbons) with divergent physicochemical properties-thereby providing fundamental mechanistic insights into information transfer across length scales.