Solar collectors based on luminescent 2, 5-diarylimidazoles. (October 2018)

• Record Type: Journal Article
• Authors: Marianetti, Giulia; Lessi, Marco; Barone, Vincenzo; Bellina, Fabio; Pucci, Andrea; Minei, Pierpaolo
• Is Part Of: Dyes and pigments. Volume 157(2018)
• Page Start: 334
• Page End: 341
• Publication Date: 2018-10
• Subjects: Push-pull azole-based fluorophores -- 2, 5-Diaryl-substituted imidazoles -- poly(methyl methacrylate) -- Dye dispersion -- Luminescent solar concentrators; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2018.04.062
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: We report on the synthesis of new fluorescent symmetrical 2, 5-diaryl-1-methylimidazoles obtained in good yields by using direct C-H arylation synthetic strategies. Spectroscopic investigations in THF solution evidenced that the 2, 5-diarylimidazole bearing the strong electron-withdrawing cyanoacrylate groups achieved the best trade-off between fluorescence maximum (518 nm), Stokes shift (115 nm) and a quantum yield of 25%. Highly homogeneous dispersions of the selected fluorophore in poly(methyl methacrylate) (PMMA) thin films (25 ± 5 μm of thickness) perfectly maintained the optical features in solution, thus providing a brilliant green emission and a markedly enhanced quantum yield of 55%. Photocurrent measurements of the PMMA collectors supported the use of 2, 5-diaryl-1-methylimidazoles as accessible alternatives to perylene backbones for the development of LSC with optical efficiencies close to 7%. Graphical abstract: Highlights: 2, 5-Diarylimidazoles are bright fluorescent in solution and in PMMA thin films. Wide Stokes shifts and good QY characterize push-pull 2, 5-diarylimidazoles. A direct arylation protocol opens the way to selected 2, 5-diarylimidazoles. Fluorescent 2, 5-diarylimidazoles are thermally stable up to 220 °C. LSCs based on push-pull azoles may be a choice cheaper than perylene-based devices.