We present a comprehensive computational study of UV/Vis absorption spectra of significant food colorants, specifically anthocyanins and curcumin tautomers, dissolved in polar protic solvents, namely water and ethanol. The absorption spectra are simulated using two fully polarizable quantum mechanical (QM)/molecular mechanics (MM) models based on the fluctuating charge (FQ) and fluctuating charge and dipoles (FQFμ) force fields. To accurately capture the dynamical aspects of the solvation phenomenon, atomistic approaches are combined with configurational sampling obtained through classical molecular dynamics (MD) simulations. The calculated QM/FQ and QM/FQFμ spectra are then compared with experiments. Our findings demonstrate that a precise reproduction of the UV/Vis spectra of the studied pigments can be achieved by adequately accounting for configurational sampling, polarization effects, and hydrogen bonding interactions.
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http://dx.doi.org/10.3390/molecules29184378 | DOI Listing |
Anal Methods
November 2017
Centre de Recherche sur la Conservation (CRC), MNHN, Sorbonne-Universités CNRS, MCC, USR 3224, CP21, 36 rue Geoffroy Saint Hilaire, 75005 Paris, France.
Reflectance spectral imaging is a powerful tool for the non-invasive study of cultural heritage objects. Particular visible to short wave infrared (400-2500 nm) spectral features are linked to compositional information. Spectral images can hence be used to generate useful chemical maps.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Environment, Zhejiang University of Technology, Hangzhou, 310014, China.
The generation of radicals through photo-Fenton-like reactions demonstrates significant potential for remediating emerging organic contaminants (EOCs) in complex aqueous environments. However, the excitonic effect, induced by Coulomb interactions between photoexcited electrons and holes, reduces carrier utilization efficiency in these systems. In this study, we develop Cu single-atom-loaded covalent organic frameworks (Cu/COFs) as models to modulate excitonic effects.
View Article and Find Full Text PDFEnviron Int
January 2025
State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, Hong Kong 999077, China; Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Hong Kong 999077, China.
Despite the ubiquity and complexity of atmospheric polycyclic aromatic compounds (PACs), many of these compounds are largely unknown and lack sufficient toxicity data for comprehensive risk assessments. In this study, nontarget screening assisted by in-house and self-developed spectra databases was, therefore, employed to identify PACs in atmospheric particulate matter collected from multiple outdoor settings. Additionally, absorption, distribution, metabolism, excretion, and toxicity properties were evaluated to indicate PAC's overall abilities to cause adverse outcomes and incorporated into a novel health risk assessment model to assess their inhalation risks.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Department of Chemistry, Government College University Faisalabad, Faisalabad 38000 Pakistan; Dry Lab (Janjua.XYZ), Physical Chemistry and Computational Modelling (PCCM), Department of Chemistry, Government College University Faisalabad, Faisalabad 38000 Pakistan. Electronic address:
Organic photovoltaics (OPVs) have improved greatly in recent years in pursuit for efficient and sustainable energy conversion methods. Specifically, utilizing quantum chemistry approaches such as density functional theory (DFT), the electronic structures, energy levels, and charge transport characteristics of donor-π-acceptor (D-π-A) systems based on non-fullerene donor and acceptor molecules have been examined and synthesized. Non-fullerene acceptors offer several advantages over traditional fullerene-based materials, such as enhanced light absorption, modifiable energy levels, and reduced recombination losses.
View Article and Find Full Text PDFPhotosynth Res
January 2025
Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan.
Pheophytin-a derivatives possessing plastoquinone and phylloquinone analogs in the peripheral 3-substituent were prepared by Friedel-Crafts reactions of a 3-hydroxymethyl-chlorin as one of the chlorophyll-a derivatives with benzo- and naphthohydroquinones, respectively, and successive oxidation of the 1,4-dihydroxy-aryl groups in the resulting dehydration products. The 3-quinonylmethyl-chlorins exhibited ultraviolet-visible absorption and circular dichroism spectra in acetonitrile, which were composed of those of the starting 3-hydroxymethyl-chlorin and the corresponding methylated benzo- and naphthoquinones. No intramolecular interaction between the chlorin and quinone π-systems was observed in the solution owing to the methylene spacer.
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