Highly efficient and tunable dual-state emission from diarylmaleimide derivatives in both solution and solid states for sensing and lighting

Abstract

Dual-state emission (DSE) materials have attracted widespread attention for their strong luminescence in both solution and solid states. However, it is still a challenge to obtain tunable DSE materials. Through tailoring the terminal groups, a series of diphenylmaleimide derivatives DPM1-DPM7 with twisted structure are designed and synthesized. These compounds not only achieve a wide range adjustment of emission color from blue to red, but also exhibit effective DSE performance. Their quantum yields in solution range from 58.2 % to 88.2 %, while the ones in solid exceed 80 %, with a maximum of nearly 100 % for three derivatives. In addition, DPM6 with tert-butoxycarbonylamino terminal group obtains three different crystals with yellow, orange and red emission. DPM6 crystals realize the reversible switching of three colors under the stimulation of solvent vapor, which can be used to identify chloroform and dichloromethane. DSE-active DPMs can be utilized to detect selectively Fe3+ ions in solution, and also has an important application in the field of solid-state lighting, realizing white light with ultra-high luminous efficiency up to 320 lm/W.