Donor–acceptor (D–A) conjugated polymers can favor the nonradiative thermal dissipation process, due to the formation of an intramolecular charge transfer (ICT) state resulting from the electron cloud delocalization of the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital). Thus, to realize a high extinction coefficient and excellent photothermal conversion ability for a single photothermal agent, donor–acceptor type conjugated polymers PBDT-QTz and PCDT-QTz, comprising a new electron-deficient unit 2-(2-decyltetradecyl)-6,7-dimethyl-2H-[1,2,3]triazolo [4,5-g] quinoxaline (QTz) as the acceptor and 4,8-di(thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene (BDT) or 4H-cyclopenta[2,1-b:3,4-b′] dithiophene (CDT) as the donor, are designed and synthesized by manipulating intramolecular motion. The high extinction coefficient of 28.5 L g⁻¹ cm⁻¹ at 850 nm and the optimal photothermal conversion efficiency of 64.3% under an 808 nm laser are achieved based on PBDT-QTz. Consequently, PBDT-QTz nanoparticles can be successfully used for both in vitro and in vivo experiments. After intravenous administration and 808 nm laser irradiation, HeLa tumor-bearing mice achieve complete tumor remission without recurrence. The results provide an efficient photothermal agent by manipulating molecular motion.

中文翻译：

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通过操纵分子运动增强基于[1,2,3]三唑并[4,5-g]喹喔啉的D-A共轭聚合物的光热治疗性能

由于HOMO（最高占据分子轨道）和LUMO（最低占据分子轨道）的电子云离域而形成分子内电荷转移（ICT）状态，因此供体-受体（D-A）共轭聚合物有利于非辐射热耗散过程。未占据的分子轨道）。因此，为了实现单一光热剂的高消光系数和优异的光热转换能力，由新的缺电子单元2-(2-癸基十四烷基)-6组成的供体-受体型共轭聚合物PBDT-QTz和PCDT-QTz， 7-二甲基-2 H- [1,2,3]三唑并[4,5- g ]喹喔啉（QTz）作为受体，4,8-二（噻吩-2-基）苯并[1,2- b： 4,5- b ']二噻吩(BDT)或4H-环戊[2,1- b :3,4- b ']二噻吩(CDT)作为供体，通过操纵分子内运动来设计和合成。基于PBDT-QTz，在850 nm处实现了28.5 L g ^-1 cm ^-1的高消光系数，在808 nm激光下实现了64.3%的最佳光热转换效率。因此，PBDT-QTz 纳米颗粒可成功用于体外和体内实验。经过静脉注射和808 nm激光照射后，HeLa荷瘤小鼠的肿瘤达到完全缓解且没有复发。结果通过操纵分子运动提供了一种有效的光热剂。