Sequence-encoded layered heteroleptic metalla-[2]catenanes for programmable supramolecular function.

Abstract

Molecular information encoded within supramolecular frameworks offers a powerful paradigm for directing emergent function beyond the genetic code, but systematic investigations into alternative spatial configurations and their consequences remain scarce. Here we use metalla-[2]catenanes to probe sequence-function relationships in layered architectures. By combining two or three size-matched N-heterocyclic carbene ligands with Ag(I) nodes, we selectively construct heteroleptic metalla-[2]catenanes through both direct assembly and supramolecular fusion pathways. X-ray crystallographic analysis unambiguously confirms the targeted sequences, while semiempirical and density functional theory calculations reveal their thermodynamic preference over alternative isomers. Photothermal conversion studies further demonstrate that sequence-specific charge-transfer interactions yield distinct macroscopic responses. Collectively, these results identify heteroleptic metalla-[2]catenanes as a robust model for elucidating how spatial arrangement governs system-level behavior and for advancing molecular coding principles in functional supramolecular design.