Photophysics of a Coumarin in Different Solvents: Use of Different Solvatochromic Models

Abstract

This study reported the photophysics of 7-(diethylamino)coumarin-3-carboxylic acid N-succinimidyl ester (7-DCCAE) in different neat solvents of varying polarity using steady-state absorption, fluorescence emission and picosecond time-resolved spectroscopy. In nonpolar solvents, the dye molecule predominantly exists in nonpolar structure and exhibits very low value of nonradiative decay rate constant (k(nr)), demonstrating the emission takes place from S(1) -LE to S(0) ground state. The fluorescence quantum yields, lifetime values of 7-DCCAE in different solvents are rationalized on the basis of intramolecular charge transfer (ICT) followed by twisted intramolecular charge transfer state formation (TICT) as well as specific solute-solvent interactions. Several solvatochromic models (such as Lippert, Dimroth, Kamlet-Taft, Catalán 3P and Catalán 4P models) were used to analyze the solvatochromic shift of 7-DCCAE in different solvents. The different empirical models show that the observed results are better correlate for nonchlorinated solvents and provide statistically significant best-fit result. A comparison was done between comparatively new solvatochromic model (Catalán 3P and Catalán 4P model) with Kamlet-Taft model. The ground state structure of the said molecule was optimized by using Density Functional Theory (DFT).

Optimization of choline chloride-glycerol based natural deep eutectic solvent for extraction bioactive substances from Cinnamomum burmannii barks and Caesalpinia sappan heartwoods

“…Meanwhile, these values for a ChCl-glycerol ratio of 1:2 (w/w) were π* = 1.18, α = 0.78, and β = 0.55 (Marcus, 2019). This finding reveals the involvement and importance of various non-specific interactions besides the hydrogen interaction in the extraction of coumarin from natural products (Maity et al., 2014). ChCl-glycerol–based NADES has higher polarity than water (Marcus, 2019; Zakerhamidi et al., 2010), explaining why coumarin levels were lower than trans-cinnamaldehyde levels under the various extraction conditions.…”

Dynamic cellular maps of molecular species: Application to drug-target interactions

“…To address these questions, in this study, we have used the 7-dimethylamino coumarin (DMAC * ) plitidepsin analog, APL * (FRET donor 4 ), as a fluorescent tracer to discriminate between APL-target complexes. Generally, the spectroscopic parameters of 7-aminocoumarins derivatives show high sensitivity to changes in microenvironment polarity, polarizability, viscosity/confinement, as well as on the solute-solvent interaction or some interactions with the surrounding media 5 – 9 . These fluorophores show large Stokes shifted fluorescence emission in polar environments, along with changes in their molar absorption coefficient, fluorescence quantum yield, and excited-state lifetimes.…”

Photophysical properties and fluorosolvatochromism of D–π–A thiophene based derivatives

“…Over the last decade, solvent dependent photophysical properties for a variety of chemical structures still found interest in literature. [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] The present work reports the spectral behaviour of a couple of thiophene-based compounds of D-p-A type, with the same structure and different electron donating groups, namely 2-uoro-4-(5-(4-methoxyphenyl)thiophen-2-yl)benzonitrile (MOT) and 4-(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2-uorobenzonitrile (DMAT). Solvent effect on their photophysical properties are to be studied and accordingly the dipole moment difference between the ground and excited states (Dm) can be evaluated.…”