Nonradiative (NR) processes are pivotal in engineering materials with tailored properties for energy utilization. However, their intrinsic rapidity and competitiveness pose huge challenges in on-demand manipulation. Herein, radical-assisted multiple NR processes were achieved to couple photothermy and photosensitization based on a unique near-infrared-absorbing diradical-featured croconium (CR) dendrimer, CR-(DPA)2-OMe. This dendrimer is well-designed by the direct covalent linkage between the flexible dendritic diphenylamine (DPA) and rigid diradical-featured CR units. The intrinsic diradical characteristics promote internal conversions in company with intramolecular donor–acceptor interactions, and the hyperfine coupling effect between the dimeric radical-ion pair excitons and adjacent magnetic nuclei assists intersystem crossing. Besides, the abundant intramolecular motions from the twisted and flexible dendritic diphenylamine groups facilitate vibrational relaxation and electron transfer. These processes endow CR-(DPA)2-OMe with a photothermal conversion efficiency of 85.05% and superoxide anion generation capability under 808 nm laser irradiation. Thus, a water evaporation efficiency of 92.6% and antibacterial efficacy under one sunlight are obtained, comprehensively superior to previously-reported organic small-molecule photothermal materials for solar-driven water evaporation. These findings highlight the importance of radicals in NR process manipulation, and significantly boosting the development of organic functional materials with on-demand excited-state energy conversions.

中文翻译：

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自由基辅助非辐射过程耦合光热和光敏化以实现太阳能驱动的水蒸发

非辐射 （NR） 工艺在工程材料中至关重要，具有针对能源利用的定制特性。然而，它们固有的速度和竞争力对按需作构成了巨大挑战。在此，基于独特的近红外吸收双自由基特征的 croconium （CR） 树枝状大分子 CR-（DPA）2-OMe，实现了自由基辅助的多个 NR 过程，以耦合光热和光敏化。该树枝状大分子通过柔性树突状二苯胺 （DPA） 和刚性双自由基特征 CR 单元之间的直接共价键精心设计。本征的双自由基特性与分子内供体-受体相互作用一起促进内部转化，二聚体自由基-离子对激子和相邻磁核之间的超精细耦合效应有助于系统间交叉。此外，来自扭曲和柔性树突二苯胺基团的丰富分子内运动促进了振动弛豫和电子转移。这些过程赋予 CR-（DPA）2-OMe 在 808 nm 激光照射下具有 85.05% 的光热转换效率和超氧阴离子产生能力。因此，在一日阳光下获得了 92.6% 的水分蒸发效率和抗菌功效，全面优于以前报道的用于太阳能驱动水分蒸发的有机小分子光热材料。这些发现强调了自由基在 NR 过程纵中的重要性，并显着促进了具有按需激发态能量转换的有机功能材料的发展。