New fluorescent monomers and polymers displaying an intramolecular proton‐transfer mechanism in the electronically excited state (ESIPT). IV. Synthesis of acryloylamide and diallylamino benzazole dyes and its copolymerization with MMA

Abstract

ABSTRACT:Six new fluorescent monomers were synthesized by reaction of 2-(5Ј-amino-2Ј-hydroxyphenyl)benzazole derivatives with acryloyl chloride and allyl bromide. UV-vis and steady-state fluorescence in solution were used to characterize its photophysical behavior. The monomers are fluorescent in the blue, green, yellow, and red region, with a large Stokes shift between 92 and 226 nm. A dual fluorescence ascribed to a conformational equilibrium in solution in the ground state dependent on the solvent polarity could be observed in the fluorescence emission spectra of the monomers. The radical polymerization of the monomers with methyl(methacrylate) allowed the production of fluorescent polymers in the blue-green region, with good optical and thermal properties.

Solid-State Luminescence with a Large Stokes Shift in Starch Functionalized with Low-Content ESIPT Dye

“…Benzazole heterocycles, aromatic compounds with a benzene-azole ring fusion, play a crucial role in heterocyclic compounds, forming benzoxazoles, benzimidazoles, benzothiazoles, or benzoselenazoles [43]. These compounds, which contain diverse heteroatoms, are fundamental building blocks in medicinal chemistry for synthesizing biologically active molecules [44][45][46][47] and photoactive polymeric materials [48][49][50][51][52][53]. Regarding ESIPT and benzazoles, hydroxyphenylbenzazoles, which can undergo proton transfer in the excited state, exist predominantly as enol (E) species in the ground state (Figure 1) [28].…”

Synthesis and comparative solvatochromic studies of novel Mono azo ureido/thioureido benzimidazole dyes

“…Their characteristic optical linear (Praveen et al , 2015) and second-order non-linear properties (Batista et al , 2007) have been studied and could to be boosted by planting hydroxyl and/or alkoxy substituents (Krawczyk, 2020). The excited state intramolecular proton transfer in these aromatic molecules leads to many fabulous applications such as photo (UV) stabilizers (Franciscato Campo et al , 2006; Ragno et al , 2006; Xu et al , 2019), selective fluorescent biological probes (Xiong et al , 2014), dye sensitizers in solar cells (Bodedla et al , 2016), laser dyes (Yang et al , 2014) and host materials for phosphorescent emitters (Karthik et al , 2016). Upon absorption of UV/Vis-light, charge-transfer (C-T) leads to conformational changes in the excited state, thus dipole moment changes (Ríos Vázquez et al , 2008).…”