Aggregation‐Induced Stabilization of Boron‐Containing Organic Diradicaliods via π‐Bridge toward Highly Efficient Light‐to‐Thermal‐Electric Conversion

An innovative strategy of aggregation‐induced stabilization is presented to achieve highly stable boron‐containing organic diradicaliods by forming different π–π stacking aggregates through cooperative π bridge and hydrogen bond regulation. Herein, three D‐π‐A‐π‐D crossover shaped molecules (PPCy‐Ph, PPCy‐Th, and PPCy‐Fu) are synthesized with π‐bridge engineering from phenyl‐, thienyl‐to furyl for precisely modulating molecular conformation and aggregation state. As the most stable boron‐containing π‐radicals to date, they all display unprecedentedly stable ESR signals at harsh conditions (300°C in air for 2 h and boiling water for 2 h) and superior photo‐, chemical‐ and thermal stability due to synergistic effect of hydrogen bonding interactions. In particular, PPCy‐Th exhibited best photothermal conversion efficiency, reaching 275°C under 808 nm laser irradiation (1.0 W cm 2 ), superior solar‐driven water evaporation rate of 1.42 kg m −2 h −1 and evaporation efficiencies (η) of 98.37%, thermoelectric power generation (256 mV) under 1 sun illumination. The multiple applications in cogeneration of water and electricity, seawater desalination, sewage treatment, laser ignition, and driving electric fan are demonstrated. Moreover, PPCy‐Fu NPs display efficient photothermal & photodynamic synergistic cancer cell killing under hypoxia. This study highlights a novel strategy for developing stable boron‐containing diradicaloids with excellent photo‐thermal conversion efficiency.