Solid-State Photoisomerization Activating Topology-Mediated Photoluminescence in a Two-Dimensional Woven Polymer

Abstract

Weaving organic molecular threads into two-dimensional topological networks offers molecular-level structural tunability and functional customization, however, achieving controllable conformational modulation without undermining lattice integrity in the solid state remains a central challenge. Here, we realize the selective photoisomerization in an emerging solid-state two-dimensional woven polymer, in which the interlaced topology provides both structural constraint and local flexibility, thereby triggering significant topology-mediated amplification of photoluminescence through the suppression of intermolecular π-π interactions. Optical and structural characterizations confirm that the emission enhancement originates from the intrinsic trans-to-cis transformation in vinylene linkers rather than optical interference or thermal effects. Polarization-dependent Raman further reveals anisotropic reorientation of C=C bonds relative to the crystal axes, evidencing lattice-scale packing reorganization induced by molecular configurational change. Consequently, cis-induced distortions propagate through mechanically coupled chains and weaken intermolecular π-π interactions, suppressing nonradiative channels to enhance photoluminescence emission. Furthermore, the partial reversibility of cis-to-trans under 532 nm irradiation enables wavelength-selective optical modulation. Our work not only unambiguously demonstrates that two-dimensional woven polymer topology translates molecular dynamics into collective structural and photophysical responses but also provides a promising platform for reversible optoelectronic regulation in organic layered materials.