Organic stoichiometric cocrystals with a subtle balance of charge-transfer degree and molecular stacking towards high-efficiency NIR photothermal conversion  

作　　者：Jieqiong Xu Wenbin Chen Shengkai Li Qian Chen Tao Wang Yadong Shi Shengyong Deng Mingde Li Peifa Wei Zhuo Chen 

机构地区：[1]Institutes of Physical Science and Information Technology,Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education,Anhui Graphene Engineering Laboratory,Anhui University,Hefei 230601,China [2]Molecular Science and Biomedicine Laboratory(MBL).State Key Laboratory of Chemo/Biosensing and Chemometrics,College of Chemistry and Chemical Engineering,College of Biology,Aptamer Engineering Center of Hunan Province,Hunan University,Changsha 410082,China [3]Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province,Shantou University,Shantou515063,China

出　　处：《Chinese Chemical Letters》2024年第10期180-186,共7页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.22001006,22375002,22273057,22225401);the Anhui Provincial Natural Science Foundation(No.2308085Y10);the Open Project of Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Anhui University,Ministry of Education;The National Key Research and Development Program of China(Nos.2022YFC_(2)403500,2020YFA0210800);The Universities Joint Laboratory of Guangdong,Hong Kong and Macao(No.130/07422011);the Natural Science Foundation of Guangdong Province(No.2022A1515011661);the China Postdoctoral Science Foundation(Nos.2023M730760,2023M740010)。

摘　　要：Charge-transfer(CT)stoichiometric cocrystals are promising choice of organic materials for unveiling the structure-property relationship.However,due to the contradiction between large CT degree required for strong NIR absorption and flexible molecular stacking,construction of stoichiomorphism-based cocystals with near-infrared(NIR)photothermal property remains challenging.Herein,the first example of stoichiomorphism-based photothermal cocrystals were accomplished through the adaptive assembly of 3,3,5,5-tetramethylbenzidine(TMB)donor and 1,2,4,5-tetracyanobenzene(TCNB)acceptor.The selective cocrystallization could be controlled by varying the donor-acceptor stoichiometries via a surfactantassisted method,resulting in two cocrystals with 1:1(T1C1)and 1:2(T2C1)stoichiometries.The absorbance intensity of T1C1 at 808 nm was nearly twice that of T2C1,while the photothermal conversion efficiency(PCE)of the former was 60.3%±0.6%,approximately 80%of that for the latter(75.5%±2.6%),which might be caused by the different intermolecular interactions in distinct molecular stacking patterns.Notably,both excellent PCEs of stoichiometric cocrystals were attributed to the nonradiative transition process,including internal conversion and charge dissociation processes,as elucidated by femtosecond transient absorption spectroscopy measurements.Furthermore,T1C1 was used as an NIR heater for preparing agarose-based photothermal hydrogel,showing great potential for light-controlled in-situ gelation.This strategy of balancing the CT degree and molecular packing orientation not only uncovered the relationship between stoichiometric stacking and photothermal property,but also provided an opportunity to develop advanced organic optoelectronic materials.

关 键 词：Charge-transfer cocrystal Stoichiometric stacking Crystal growth Photothermal conversion In-situ gelation 

分 类 号：TB322[一般工业技术—材料科学与工程]