Photophysical Properties of Coumarin Compounds in Neat and Binary Solvent Mixtures: Evaluation and Correlation Between Solvatochromism and Solvent Polarity Parameters

Moreira, Leonardo Marmo; Melo, Mírian de Lourdes Noronha Motta; Martins, Priscila A.; Lyon, Juliana Pereira; Romani, Ana Paula; Codognoto, Lúcia; Santos, Sandra Carvalho dos; Oliveira, Hueder Paulo Moisés de

doi:10.5935/0103-5053.20140051

Cited by 6 publications

(4 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Solvation and coulombic effects are responsible for often observed differences between electrochemical and optical band gaps [ 44 ]. Additionally, the solvatochromic nature of substituted coumarins [ 45 , 46 ] leads to a shorter band gap in more polar solvent, which is the case with DMF.…”

Section: Resultsmentioning

confidence: 99%

New 3-Ethynylaryl Coumarin-Based Dyes for DSSC Applications: Synthesis, Spectroscopic Properties, and Theoretical Calculations

et al. 2021

View full text Add to dashboard Cite

A set of 3-ethynylaryl coumarin dyes with mono, bithiophenes and the fused variant, thieno [3,2-b] thiophene, as well as an alkylated benzotriazole unit were prepared and tested for dye-sensitized solar cells (DSSCs). For comparison purposes, the variation of the substitution pattern at the coumarin unit was analyzed with the natural product 6,7-dihydroxycoumarin (Esculetin) as well as 5,7-dihydroxycomarin in the case of the bithiophene dye. Crucial steps for extension of the conjugated system involved Sonogashira reaction yielding highly fluorescent molecules. Spectroscopic characterization showed that the extension of conjugation via the alkynyl bridge resulted in a strong red-shift of absorption and emission spectra (in solution) of approximately 73–79 nm and 52–89 nm, respectively, relative to 6,7-dimethoxy-4-methylcoumarin (labs = 341 nm and lem = 410 nm). Theoretical density functional theory (DFT) calculations show that the Lowest Unoccupied Molecular Orbital (LUMO) is mostly centered in the cyanoacrylic anchor unit, corroborating the high intramolecular charge transfer (ICT) character of the electronic transition. Photovoltaic performance evaluation reveals that the thieno [3,2-b] thiophene unit present in dye 8 leads to the best sensitizer of the set, with a conversion efficiency (η = 2.00%), best VOC (367 mV) and second best Jsc (9.28 mA·cm−2), surpassed only by dye 9b (Jsc = 10.19 mA·cm−2). This high photocurrent value can be attributed to increased donor ability of the 5,7-dimethoxy unit when compared to the 6,7 equivalent (9b).

show abstract

Section: Resultsmentioning

confidence: 99%

New 3-Ethynylaryl Coumarin-Based Dyes for DSSC Applications: Synthesis, Spectroscopic Properties, and Theoretical Calculations

et al. 2021

View full text Add to dashboard Cite

show abstract

“…It has been reported that conversion of the carboxy group of 10 to amide increases the fluorescence intensity in 1,4-dioxane, which is a nonpolar solvent . Such a solvent polarity-dependent fluorescence intensity change reflects the degree of intramolecular charge transfer (ICT) in the excited state. − …”

Section: Resultsmentioning

confidence: 99%

Convenient Retinoid X Receptor Binding Assay Based on Fluorescence Change of the Antagonist NEt-C343

et al. 2020

View full text Add to dashboard Cite

Retinoid X receptor (RXR) modulators (rexinoids) are considered to have therapeutic potential for multiple diseases, such as Alzheimer’s disease and Parkinson’s disease. To overcome various disadvantages of prior screening methods, we previously developed an RXR binding assay using a fluorescent RXR ligand, CU-6PMN (4). However, this ligand binds not only at the ligand-binding domain (LBD) but also at the dimer–dimer interface of hRXRα. Here, we present a new fluorescent RXR antagonist 6-[N-ethyl-N-(5-isobutoxy-4-isopropyl-2-(11-oxo-2,3,6,7-tetrahydro-1H,5H,11H-pyrano[2,3-f]pyrido[3,2,1-ij]quinoline-10-carboxamido)phenyl)amino]nicotinic acid (NEt-C343, 7), which emits strong fluorescence only when bound to the RXR-LBD. It allows us to perform a rapid, simple, and nonhazardous binding assay that does not require bound/free separation and uses a standard plate reader. The obtained Ki values of known compounds were correlated with the Ki values obtained using the standard [3H]9cis-retinoic acid assay. This assay should be useful for drug discovery as well as for research on endocrine disruptors, functional foods, and natural products.

show abstract

“…Technological advancements have led to the development of new equipment, which has improved the precision and accuracy of existing techniques used to detect and quantify coumarins even in very low concentration. These techniques include HPLC with diode array detection (DAD) and fluorescence detector (FLD) coupled to mass spectrometry (MS), GC or LC coupled to ESI-MS, MS-time of flight (TOF), MS-ion trap and MS-MS tandem quadrupole (Q)-TOF [43,[170][171][172][173][174][175][176][177][178].…”

Section: Spectrometric Detectorsmentioning

confidence: 99%

Coumarins in Spirit Beverages: Sources, Quantification, and Their Involvement in Quality, Authenticity and Food Safety

Oliveira-Alves,

Lourenço,

Fernandes

et al. 2024

Applied Sciences

View full text Add to dashboard Cite

This comprehensive review is devoted to an under-exploited family of phenolic compounds, the coumarins, and the most relevant strands in which they are involved in some spirit beverages—wine spirit, brandy, whiskey, sugar-cane spirits (rum and cachaça) and grape marc spirit—with great importance worldwide in terms of production, trade and consumption. It gathers the key discoveries on the topic, considering the production process of each spirit beverage, and the related sources of coumarins (different kinds of wood used in the ageing stage), along with the factors that govern them and can influence the sensory properties of the aged beverages. An overview of the analytical methods available for their identification/quantification is also included, as well as the corresponding trends for the advancement of knowledge in this field. Moreover, the remarkable role of coumarins as nutraceuticals, their importance as chemical markers for authenticity purposes, and their relationship with the food safety of these spirit beverages are also addressed, highlighting the current gaps and issues, and providing clues for future research.

show abstract

Photophysical Properties of Coumarin Compounds in Neat and Binary Solvent Mixtures: Evaluation and Correlation Between Solvatochromism and Solvent Polarity Parameters

Cited by 6 publications

References 4 publications

New 3-Ethynylaryl Coumarin-Based Dyes for DSSC Applications: Synthesis, Spectroscopic Properties, and Theoretical Calculations

New 3-Ethynylaryl Coumarin-Based Dyes for DSSC Applications: Synthesis, Spectroscopic Properties, and Theoretical Calculations

Convenient Retinoid X Receptor Binding Assay Based on Fluorescence Change of the Antagonist NEt-C343

Coumarins in Spirit Beverages: Sources, Quantification, and Their Involvement in Quality, Authenticity and Food Safety

Contact Info

Product

Resources

About