Perylene diimide-based crystalline frameworks: design strategies, electronic structure engineering and emerging functionalities

Perylene diimide (PDI) is a representative electron-deficient organic semiconductor featuring a rigid π-conjugated structure, strong visible-light absorption, high chemical stability, and excellent electron-transport properties. Its low-lying LUMO energy level enables reversible redox behavior and stable radical anion formation, making PDI an important building block for optoelectronic and energy-related applications. However, molecular PDI systems often suffer from aggregation-induced quenching and limited charge transport. Rational construction of PDI into crystalline frameworks, including COFs, MOFs, and HOFs, provides an effective structural design strategy to overcome these limitations through ordered assembly and enhanced π–π interactions. Such crystalline architectures facilitate long-range charge transport, exciton migration, and charge separation while suppressing charge recombination. More importantly, PDI-based crystalline frameworks function as programmable electronic-structure platforms capable of regulating charge transport, polarization, radical stabilization, and energy conversion. Their porous and tunable structures further optimize local electronic environments and mass transport, enabling emerging functionalities in sensing, selective adsorption, photothermal conversion, and photocatalysis, etc. This review summarizes recent advances in PDI crystalline frameworks from the perspectives of structural design strategies and electronic structure engineering, highlighting the intrinsic relationships among framework structure, electronic behavior, and functional performance, as well as future challenges and design principles for advanced functional crystalline materials.