Structural design of porous organic polymers to mitigate π-stacking-induced quenching in porphyrin/phthalocyanine photosensitizers for enhanced antibacterial activity

Abstract

Porphyrins and phthalocyanines are cornerstone molecular architectures for photodynamic therapy (PDT), organic photovoltaics, and artificial photosynthesis, prized for their exceptional photophysical properties. However, their extended planar π-conjugated systems inevitably induce aggregation-caused quenching (ACQ) through strong π–π stacking interactions, severely diminishing critical performance metrics like photothermal conversion efficiency and reactive oxygen species (ROS) generation. Porous organic polymers (POPs) have emerged as a transformative platform to overcome this limitation, offering unique capabilities for spatially isolating these photoactive units while maintaining structural integrity and enabling precise porosity control. This comprehensive review systematically analyzes structure-property relationships in porphyrin/phthalocyanine-based POPs. It presents detailed case studies showcasing effective π-stacking suppression strategies and offers forward-looking perspectives for designing next-generation materials optimized for photophysical performance. Key design strategies include host–guest architectures (e.g., β-cyclodextrin-threaded Por-CD-COF), modulating interlayer spacing to enhance photodynamic efficiency, stereochemical engineering (e.g., isomeric iso-CMPs), leveraging steric hindrance to prevent π-stacking while amplifying enzyme-mimetic activities, and dynamic covalent linkages (e.g., imine/boronate bonds), enabling stimuli-responsive chromophore repositioning, multi-component hybrids (e.g., MOF@COF heterostructures), integrating catalytic cores with photoactive shells for synergistic performance enhancement. By summarizing key advances and providing forward-looking perspectives, this review aims to inspire the rational design of next-generation POP-based materials with optimized photophysical properties, paving the way for their broader application in antimicrobial therapy, energy conversion, and beyond.