Dual fluorescence switching of a Rhodamine 6G-naphthalimide conjugate with high contrast in the solid state. Issue 38 (12th September 2018)

• Record Type: Journal Article
• Authors: Tan, Lina; Mo, Shenzhong; Fang, Bing; Cheng, Wenyu; Yin, Meizhen
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 38(2018)
• Page Start: 10270
• Page End: 10275
• Publication Date: 2018-09-12
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8tc03654c
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : A novel Rhodamine 6G-naphthalimide molecule is used for high-contrast fluorescence change upon acid and force stimuli in the solid state. Abstract : Solid-state fluorescence switches have attracted tremendous attention in recent years owing to their applications in fluorescent sensors, security inks and data storage. Herein, we report a novel molecule (2NR ) composed of two naphthalimide moieties and a Rhodamine 6G (R6G) unit linked by a branched amidoamine spacer.2NR exhibits excellent acid and force dual-stimuli-responsive behaviour in the solid state: (i) exposing2NR powder to HCl vapour results in fluorescence off–on switching, because protonation of the tertiary amine by acid impedes the photoinduced electron transfer process; (ii) further treatment with grinding, the force-induced open-ring reaction of R6G and subsequent efficient fluorescence resonance energy transfer from naphthalimide to the open-ring form of R6G realizes a high-contrast fluorescent colour change. Moreover, the branched amidoamine spacer induces a twisted conformation of naphthalene moieties, which provides considerable free volume and significantly facilitates the isomerization process of R6G from spirolactam to open-ring amide. Both fluorescence switches have good reversibility. Consequently, the excellent solid-state fluorescent switching of2NR is highly applicable for anti-counterfeiting materials.