華東師范大學化學與分子工程學院教授徐林和精密光譜科學與技術(shù)國家重點實驗室研究員孫海濤課題組跨學科合作，在超分子光化學領(lǐng)域取得進展，實現(xiàn)了三代功能化輪烷樹狀分子合成。相關(guān)研究成果近日發(fā)表于《美國化學會志》。
Xu Lin, a professor in the School of Chemistry and Molecular Engineering of East China Normal University, and Sun Haitao, a researcher in the State Key Laboratory of Precision Spectroscopy Science and Technology, cooperated with each other across disciplines to make progress in the field of supramolecular photochemistry and realize the synthesis of three generations of functionalized rotaxane dendrimers. The relevant research results were recently published in the Journal of the American Chemical Society.
因在光動力治療、光敏催化以及3D打印等領(lǐng)域的廣泛應用，發(fā)展新的簡易平臺體系對于構(gòu)筑高效率光敏劑具有重要價值?？茖W家認為，集成樹枝狀分子和機械互鎖分子的雙重優(yōu)勢而發(fā)展的輪烷樹狀分子有望作為構(gòu)筑高效光敏劑的平臺體系。
Due to its wide application in photodynamic therapy, photocatalysis, and 3D printing, the development of new simple platform systems is of great value for constructing high-efficiency photosensitizers. Scientists believe that the development of cyclohexane dendrites, which integrate the dual advantages of dendritic molecules and mechanically interlocked molecules, has the potential to serve as a platform system for constructing efficient photosensitizers.
為此，研究人員分別發(fā)揮各自在超分子光學體系構(gòu)建以及量子理論計算方面的優(yōu)勢，對光敏劑的光敏化機理進行了分子設計。通過簡單高效的合成方法，成功地在輪烷基元的軸和輪上分別引入多個重原子鉑和光敏基元蒽，利用可控發(fā)散策略，實現(xiàn)了三代功能化輪烷樹狀分子的合成。輪烷樹狀分子骨架上含有21個鉑原子和42個光敏基元蒽，是迄今為止合成的重原子和光敏基元最多且分布精準的分立多輪烷光敏劑體系之一。
To this end, researchers have utilized their respective advantages in the construction of supramolecular optical systems and quantum theory calculations to design molecular mechanisms for the photosensitization of photosensitizers. Through a simple and efficient synthesis method, multiple heavy atoms of platinum and photosensitive element anthracene were successfully introduced into the axis and wheel of the alkyl ring, respectively. By utilizing a controllable divergence strategy, the synthesis of third-generation functionalized alkyl tree like molecules was achieved. The branched molecular skeleton of cyclohexane contains 21 platinum atoms and 42 photosensitive units anthracene, making it one of the most synthesized and accurately distributed discrete multi cyclohexane photosensitizer systems with the most heavy atoms and photosensitive units to date.
研究結(jié)果表明，通過在輪烷基元的軸和輪上分別引入多個鉑原子和蒽光敏基團，可以明顯提高光敏劑的旋軌耦合常數(shù)和增加能量躍遷通道來促進系間竄越（ISC），從而有效提高光敏化效率。同時，輪烷樹狀分子剛性骨架具有獨特空間立體效應，可以避免分子內(nèi)或分子間光敏劑之間的聚集，有利于保持光敏劑的高效光敏化活性。
The research results indicate that by introducing multiple platinum atoms and anthracene photosensitive groups on the axis and wheel of the alkyl group, the spin orbit coupling constant of the photosensitizer can be significantly improved and the energy transition channel can be increased to promote intersystem crossing (ISC), thereby effectively improving the photosensitization efficiency. At the same time, the rigid skeleton of cyclohexane dendrites has a unique spatial stereo effect, which can avoid the aggregation of photosensitizers within or between molecules, and is conducive to maintaining the efficient photosensitizing activity of photosensitizers.
同時，研究人員詳細研究了這一系列新型輪烷樹狀分子光敏劑結(jié)構(gòu)與性質(zhì)之間的關(guān)系，發(fā)現(xiàn)該輪烷樹狀分子的光敏化效率隨著代數(shù)增長而逐漸增加。第一、二和三代輪烷樹狀分子的單線態(tài)氧產(chǎn)率分別是其相應單體的1.8、4.5和13.3倍。
At the same time, researchers conducted a detailed study on the relationship between the structure and properties of this series of novel cyclohexane dendrimer photosensitizers, and found that the photosensitization efficiency of the cyclohexane dendrimer gradually increases with algebraic growth. The singlet oxygen yields of the first, second, and third generation cyclohexane dendrimers are 1.8, 4.5, and 13.3 times higher than their corresponding monomers, respectively.
研究人員表示，新型功能化輪烷樹狀分子不僅可作為制備高效光敏劑的平臺體系，而且在人工光捕獲、光解材料和動態(tài)智能材料方面具有重要的潛在應用價值。
Researchers have stated that the novel functionalized cyclohexane dendrimers not only serve as a platform system for preparing efficient photosensitizers, but also have significant potential applications in artificial light capture, photolysis materials, and dynamic intelligent materials.