Synthesis and spectroscopic characterization of Y-shaped fluorophores with an imidazole core containing crown ether moieties


Dogru U., ÖZTÜRK ÜRÜT G., Bayramin D.

JOURNAL OF LUMINESCENCE, vol.163, pp.32-39, 2015 (SCI-Expanded, Scopus) identifier identifier

  • Publication Type: Article / Article
  • Volume: 163
  • Publication Date: 2015
  • Doi Number: 10.1016/j.jlumin.2015.03.001
  • Journal Name: JOURNAL OF LUMINESCENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.32-39
  • Keywords: Imidazole, Y-shaped molecules, Crown ether, 15-Crown-5
  • Dokuz Eylül University Affiliated: Yes

Abstract

In this study three new Y-shaped fluorophores, 4,5-(2,2'-diphenyl)vinyl-{2-[(1,4,7,10-tetraoxa-13-azacyclopentadecyl)phenyl]}-1H-imidazole (1a), 4,5{[2,2'-bis(4-methoxyphenyl)vinyl]-[2-(1,4,7,10-tetraoxa-13-azacyclopentadecyl)-phenyl])-1H-imidazole (1b) and 4,5-(2,2'-diphenyl)vinyl-{2-(1,4,7,10,13-benzopentaoxacyclopentadecyl))-1H-imidazole (1c) were synthesized. 1,6-Diphenylhexa-1,5-diene-3,4-dione (2a) and 1,6-bis(4-methoxyphenyl)hexa-1,5-diene-3,4-dione (2b) were synthesized as preliminary fluorophores and then reacted with 4-formylbenzo-aza-15-crown-5 (3a) and 4-formylbenzo-15-crown-5 (3b) to obtain the three Y-shaped fluorophores 1a, 1b and 1c. 4-formylbenzo-aza-15-crown-5 and 4-formylbenzo-15-crown-5 intermediates were synthesized with Vilsmeier-Haack reaction. The photophysical properties such as maximum absorption wavelengths, maximum emission wavelengths, Stokes shifts, singlet energies, fluorescence quantum yields and photostabilities of the compounds were investigated by measuring absorption and emission spectra in a series of solvents of varying polarities of toluene (TOL), dichloromethane (DCM), tetrahydrofuran (THF), ethyl acetate (EA), acetonitrile (ACN), and N,N-dimethylformamide (DMF). The three compounds 1a, 1b and 1c exhibited emission maxima in the 412-677 nm range. All the derivatives synthesized exhibited excellent photostability in all the solvents tested. (C) 2015 Elsevier B.V. All rights reserved.