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3 Typical AIEgens Design: Salicylaldehyde Schiff Base
Yue Zheng and Aijun Tong
Department of Chemistry, Tsinghua University, Beijing, China
3.1 Introduction
3.1.1 AIE and ESIPT of Salicylaldehyde Schiff Base
A Schiff base (named after Hugo Schiff [1]) is a compound with the general structure R2C = NR′ (R′ ≠ H). It is a subclass of imines, being either secondary ketimines or aldimines formed by the condensation of active carbonyl groups of ketones or aldehydes with primary amines, respectively [2]. In salicylaldehyde Schiff base (SSB) derivatives, including salicylaldehyde azine and salicylidene aniline, imine and ortho‐hydroxyl groups can form stable six‐membered ring structures through intramolecular hydrogen bonding, which allows the entire molecule to rotate freely around nitrogen–nitrogen