陕西师范大学房喻团队报道了通过结合电荷转移实现高性能薄膜荧光传感的激发态分子内质子转移的精确操纵。相关研究成果发表在2023年3月17日出版的国际学术期刊《美国化学会杂志》。

激发态分子内质子转移（ESIPT）已被广泛用于设计各种功能性主导的分子系统。然而，激发态反应的精确操作是具有挑战性的。

该文中，研究人员报道了一种通过引入激发态分子内电荷转移（ESICT）过程来调节ESIPT的新策略。具体而言，设计了三种邻碳硼烷衍生物，NaCBO、PaCBO和PyCBO，其中2-（2′-羟基苯基）-苯并噻唑是一种典型的ESIPT单元，起到电子受体的作用，给电子单元分别是萘基-（Na）、菲基-（Pa）和芘基-（Py）。分子的结构特征是两个单元面对面排列。光谱学和理论计算研究表明，供体的给电子能力和溶剂极性连续调节ESIPT/ESICT的能量学和动力学，导致不同的发光。

此外，这些分子不仅在固态中具有高度孔隙结构，而且还具有非常不同的荧光颜色，使得能够对芥子气模拟物2-氯乙基乙基硫醚进行高度选择性的基于膜的荧光传感，检测极限为50ppb，响应时间为5s。因此，该项工作为通过ESIPT操作创建高性能传感荧光团提供了可靠的策略。

附：英文原文

Title: Precise Manipulation of Excited-State Intramolecular Proton Transfer via Incorporating Charge Transfer toward High-Performance Film-Based Fluorescence Sensing

Author: Ke Liu, Jing Zhang, Qiyuan Shi, Liping Ding, Taihong Liu, Yu Fang

Issue&Volume: March 17, 2023

Abstract: Excited-state intramolecular proton transfer (ESIPT) has been widely employed for the design of a variety of functionality-led molecular systems. However, precise manipulation of the excited-state reaction is challenging. Herein, we report a new tactic for tuning ESIPT via incorporating an excited-state intramolecular charge transfer (ESICT) process. Specifically, three o-carborane derivatives, NaCBO, PaCBO, and PyCBO, were designed, where the 2-(2′-hydroxyphenyl)-benzothiazole is a typical ESIPT unit functioning as an electron acceptor, and the electron-donating units are naphthyl-(Na), phenanthrenyl-(Pa), and pyrenyl-(Py), respectively. The architectures of the molecules are featured with a face-to-face alignment of the two units. Spectroscopy and theoretical calculation studies revealed that the electron-donating capacity of the donors and solvent polarity continuously modulate the ESIPT/ESICT energetics and dynamics, resulting in distinct emissions. Moreover, the molecules depicted not only highly porous structures but also very different fluorescent colors in the solid state, enabling highly selective film-based fluorescence sensing of mustard gas simulant, 2-chloroethyl ethyl sulfide, with a detection limit of 50 ppb and a response time of 5 s. This work thus provides a reliable strategy for the creation of high-performance sensing fluorophores via ESIPT manipulation.

DOI: 10.1021/jacs.2c13843

Source: https://pubs.acs.org/doi/10.1021/jacs.2c13843