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 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 characterization studies 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 spectroscopy results further reveal anisotropic reorientation of CC bonds relative to the crystal axes, evidencing lattice-scale packing reorganization induced by molecular configurational changes. Consequently, cis-induced distortions propagate through mechanically coupled chains and weaken intermolecular π–π interactions, suppressing nonradiative channels and thereby enhancing 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.