Synthesis and photophysical properties of photostable 1, 8-naphthalimide dyes incorporating benzotriazole-based UV absorbers. Issue 27 (13th June 2022)

• Record Type: Journal Article
• Authors: Uesaka, Toshiyuki; Ishitani, Tomoyuki; Shimeno, Takahito; Suzuki, Naoya; Yagi, Shigeyuki; Maeda, Takeshi
• Is Part Of: RSC advances. Volume 12:Issue 27(2022)
• Page Start: 17350
• Page End: 17361
• Publication Date: 2022-06-13
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2ra02028a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Highly photostable blue fluorescence dyes were developed by hybridization of 1, 8-naphthalimides with benzotriazole-based UV absorbers enabling a non-radiative energy dissipation process of excited-state intramolecular proton transfer (ESIPT). Abstract : We developed a series of blue-emitting 1, 8-naphthalimide dyes covalently attached to 2-(2-hydroxyphenyl)-2 H -benzotriazoles that retard photodegradation of the fluorophore. The dyes displayed weaker fluorescence emissions than the parent 1.8-naphthalimide. Quantum chemical calculations suggested that the decreased fluorescence was caused by the nonradiative deactivation promoted through the excited state intramolecular proton transfer (ESIPT) in benzotriazole components. The dyes' phosphorescences in a degassed solution at 77 K were more efficient than that of the parent 1.8-naphthalimide, indicating a possible deactivation pathway through intersystem crossing. PMMA films doped with these dyes showed higher resistance against photoaging than the film doped with an equimolar mixture of constituent 1.8-naphthalimide and the benzotriazole derivatives. Thus, the covalently linked benzotriazole units slow fluorophore degradation not only by preferential absorption of harmful UV light, which is found in the film with a simple mixture of two components, but also by the nonradiative deactivation involved in benzotriazole units.