Cooperativity of ESPT and Aggregation-Induced Emission Effects-An Experimental and Theoretical Analysis of a 1,3,4-Thiadiazole Derivative.
Int J Mol Sci
; 25(6)2024 Mar 15.
Article
en En
| MEDLINE
| ID: mdl-38542326
ABSTRACT
4-[5-(Naphthalen-1-ylmethyl)-1,3,4-thiadiazol-2-yl]benzene-1,3-diol (NTBD) was extensively studied through stationary UV-vis absorption and fluorescence measurements in various solvents and solvent mixtures and by first-principles quantum chemical calculations. It was observed that while in polar solvents (e.g., methanol) only a single emission band emerged; the analyzed 1,3,4-thiadiazole derivative was capable of producing dual fluorescence signals in low polarity solvents (e.g., n-hexane) and certain solvent mixtures (e.g., methanol/water). As clearly follows from the experimental spectroscopic studies and theoretical modeling, the specific emission characteristic of NTBD is triggered by the effect of enol â keto excited-state intramolecular proton transfer (ESIPT) that in the case of solvent mixture is reinforced by aggregation of thiadiazole molecules. Specifically, the restriction of intramolecular rotation (RIR) due to environmental hindrance suppresses the formation of non-emissive twisted intramolecular charge transfer (TICT) excited keto* states. As a result, this particular thiadiazole derivative is capable of simultaneously producing both ESIPT and aggregation-induced emission (AIE).
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Base de datos:
MEDLINE
Asunto principal:
Tiadiazoles
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Metanol
Idioma:
En
Revista:
Int J Mol Sci
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Int. j. mol. sci. (Online)
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International journal of molecular sciences (Online)
Año:
2024
Tipo del documento:
Article