Design and Synthesis of Anthracene/Pyrene-Based Triazine-Centered D–A–D′ Type Fluorescent Molecules: Linking Photophysical Properties and Morphology for Explosives Detection

Abstract

Nitroaromatic compounds are widely used in industrial and military applications, making their rapid and sensitive detection an important scientific challenge. Although numerous luminescent materials have been developed for nitroaromatic sensing, the fundamental molecular and morphological parameters governing sensing performance remain poorly understood, limiting the rational design of next-generation sensors. Herein, we establish the key design principles underlying nitroaromatic sensing in both solution and solid states using a series of donor–acceptor–donor (D–A–D′) luminophores comprising anthracene or pyrene as the donor D, triazine as the acceptor A, and triphenylamine or diphenylamine as the donor D′. By systematically correlating molecular structure, photophysical properties, and sensing performance, we demonstrate that the intramolecular charge-transfer (ICT) character is the dominant factor governing quenching efficiency in solution, while high quantum yield and longer excited-state lifetimes further enhance sensitivity. In contrast, solid-state sensing is primarily dictated by molecular morphology, where larger surface areas facilitate analyte adsorption and improve sensor performance. These results reveal distinct yet complementary molecular and morphological factors controlling nitroaromatic sensing across different phases and provide a unified framework for the rational design of high-performance luminescent sensing materials.