Photochromic diarylethene induced fluorescence switching materials constructed by non-covalent interactions

Photochromic fluorescent switches, whose emission can be reversibly switched upon light irradiation, have emerged as extremely promising materials in the last decade owing to their potential applications in biological and materials sciences. Diarylethylenes are a promising class of photochromic molecules with excellent phototriggering properties. Although some diarylethenes themselves can be used as fluorescent switches, a more efficient way to prepare photochromic fluorescent switches is to combine diarylethene with an energy-level matched fluorophore via non-covalent assembly, which not only fully utilizes the diversity of fluorophores and diarylethenes, but also easily enables the integration of multiple functions. Moreover, non-covalent assembly methods often bring many unintended results, favorable for the design and fabrication of the new generation of smart materials. Here, the construction of diarylethene-based photochromic fluorescent switches by non-covalent assembly is reviewed. The structure design principle of diarylethenes and fluorophores, the cross-talk between different components and the integration of stimuli-response features in the photochromic fluorescence switching systems are discussed. Non-covalent assembly modes and photochromic fluorescence switching mechanisms that have great guiding significance for the design of photochromic fluorescent switches are also summarized. This review summarizes recent developments of diarylethene-based photochromic fluorescence switches constructed by non-covalent interactions, and the structural design principles of diarylethenes and fluorophores are discussed.