title: Photophysical properties of ESIPT inspired fluorescent 2-(2-hydroxyphenyl)-6-methylimidazo[4,5-f]isoindole-5,7(1H,6H)-dione and its derivative: experimental and DFT based approach.
abstract: The excited-state intramolecular proton transfer chromophores 2-(2-hydroxyphenyl)-6-methylimidazo[4,5-f]isoindole-5,7(1H,6H)-dione and 2-(4-(diethylamino)-2-hydroxyphenyl)-6-methylimidazo[4,5-f]isoindole-5,7(1H,6H)-dione are synthesized from 4,5-diamino-N-methylphthalimide. The photophysical behavior of the synthesized chromophores was studied using UV-visible and fluorescence spectroscopy in the polar and non-polar solvents. The synthesized o-hydroxyphenyl benzimidazole derivatives are fluorescent and very sensitive to the solvent polarity. These dyes are thermally stable up to 317 °C. Density Functional Theory computations have been used to understand the structural, molecular, electronic and photophysical properties of the chromophores. The experimental absorption and emission wavelengths are in good agreement with the computed vertical excitation and theoretical emission obtained by Density Functional Theory and Time Dependant Density Functional Theory.
authors.affiliation: Tinctorial Chemistry Group, Dyestuff Technology Department, Institute of Chemical Technology (Formerly UDCT), N.P. Marg, Matunga, Mumbai 400 019, Maharashtra, India.
authors.forename: Mininath S
authors.initials: MS
authors.lastname: Deshmukh
authors.affiliation: Tinctorial Chemistry Group, Dyestuff Technology Department, Institute of Chemical Technology (Formerly UDCT), N.P. Marg, Matunga, Mumbai 400 019, Maharashtra, India. Electronic address: n.sekar@ictmumbai.edu.in.
authors.forename: Nagaiyan
authors.initials: N
authors.lastname: Sekar
mesh_terms: D004583:Electrons; D007093:Imidazoles / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles / Q000737:chemistry*; D008027:Light; D008958:Models, Molecular; D008968:Molecular Conformation; D055585:Physical Phenomena; D011522:Protons; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: C000598709:2-(2-hydroxyphenyl)-6-methylimidazo(4,5-f)isoindole-5,7(1H,6H)-dione; D007093:Imidazoles; D007211:Indoles; D054833:Isoindoles; D011522:Protons; D012997:Solvents
keywords: ESIPT; Fluorescence; Solvatochromism; TD-DFT; Thermal stability; o-Hydroxyphenyl benzimidazole