Search results for "Chemical physics"
showing 10 items of 2553 documents
Coherent Light Harvesting through Strong Coupling to Confined Light
2018
When photoactive molecules interact strongly with confined light modes, new hybrid light-matter states may form: the polaritons. These polaritons are coherent superpositions of excitations of the molecules and of the cavity photon. Recently, polaritons were shown to mediate energy transfer between chromophores at distances beyond the Förster limit. Here we explore the potential of strong coupling for light-harvesting applications by means of atomistic molecular dynamics simulations of mixtures of photoreactive and non-photo-reactive molecules strongly coupled to a single confined light mode. These molecules are spatially separated and present at different concentrations. Our simulations sug…
Single- and Double-Strand Breaks of Dry DNA Exposed to Protons at Bragg-Peak Energies
2017
International audience; Ultrathin layers (<20 nm) of pBR322 plasmid DNA were deposited onto 2.5 μm thick polyester films and exposed to proton Bragg-peak energies (90–3000 keV) at various fluences. A quantitative analysis of radio-induced DNA damage is reported here in terms of single- and double-strand breaks (SSB and DSB, respectively). The corresponding yields as well as G-values and the cross sections exhibit fairly good agreement with the rare available data, stemming from close experimental conditions, namely, based on α particle irradiation. SSB/DSB rates appear to be linear when plotted against linear energy transfer (LET) in the whole energy range studied. All the data present a ma…
Naphthalene-2,6-diyl bis(4-methylbenzenesulfonate)
2018
The complete molecule of the title compound, C24H20O6S2, is generated by a crystallographic inversion centre at the middle of the naphthalene ring system. The dihedral angle between the naphthalene ring system and the pendant benzene ring is 10.23 (6)° and the C—S—O—C torsion angle is −172.05 (10)°. In the crystal, weak C—H...O interactions link the molecules into (10-1) sheets.
4-Chloronaphthalen-1-yl 4-methylbenzenesulfonate
2018
In the title compound, C17H13ClO3S, the naphthalene ring system and the benzene ring of the tosylate substituent are inclined to one another by 55.32 (5)°. The crystal structure features weak intermolecular C—H...O hydrogen bonds, one of which forms inversion dimers. Additional C—H...O hydrogen bonds and weak Cl...Cl halogen bonds stack the molecules along the b-axis direction.
Crystal structure of 2-{[1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-yloxy]carbonyl}benzoic acid
2014
In the title compound, C15H15N3O6, the dihedral angle between the planes of the benzene and imidazole rings is 34.93 (10)°. An intramolecular C—H...O hydrogen bond is observed. In the crystal, O—H...N hydrogen bonds link the molecules into chains parallel to thecaxis.
Crystal structure of 3-mesityl-1-[(pyridin-2-yl)methyl]-3,4,5,6-tetrahydropyrimidin-1-ium bromide monohydrate
2015
In the title hydrated salt, C19H24N3+·Br−·H2O, the values of the N—C bond lengths within the tetrahydropyrimidinium ring indicate delocalization of the N=C double bond. In the cation, the dihedral angle formed by the pyridine and benzene rings is 14.97 (12)°. In the crystal, ions and water molecules are linked by O—H...Br, O—H...N, C—H...Br and C—H...O hydrogen bonds into chains running parallel to thebaxis.
Crystal structure and computational study of 3,4-dihydroxy-3-hydroxymethyl-9-methyl-6-methylidene-3a, 4,5,6,6a, 9,9a, 9b-octahydroazuleno[4,5-b]furan…
2015
WOS: 000370762300147
Bis{4-[(2-hydroxy-5-methoxy-3-nitrobenzylidene)amino]phenyl} ether
2020
The molecule of the title oxybis compound lies on a twofold rotational axis. The conformation of the title compound is discussed and compared to those of related structures. In the crystal, molecules of the title compound are assembled into layers parallel to the ab plane through C—H⋯O hydrogen bonds.
Structural Features of β-Cyclodextrin Solvation in the Deep Eutectic Solvent, Reline
2020
The inherently amphiphilic nature of native cyclodextrins (CDs) determines their peculiar molecular encapsulation features, enabling applications such as targeted drug nanodelivery, aroma protection, etc. On the contrary, it may also lead to poor solubility in water and other organic solvents and to potentially detrimental flocking in these media, thus posing limitations to more extensive usage. Here we use small angle X-ray scattering to show that deep eutectic solvent reline (1:2 choline chloride:urea) succeeds in dissolving large amounts of beta-CD (at least 800 mg/mL, compared with the solubility in water of 18 mg/mL), without aggregation phenomena occurring. At the microscopic level, m…
Combined dynamics of the 500–600 nm leaf absorption and chlorophyll fluorescence changes in vivo: Evidence for the multifunctional energy quenching r…
2021
Carotenoids (Cars) regulate the energy flow towards the reaction centres in a versatile way whereby the switch between energy harvesting and dissipation is strongly modulated by the operation of the xanthophyll cycles. However, the cascade of molecular mechanisms during the change from light harvesting to energy dissipation remains spectrally poorly understood. By characterizing the in vivo absorbance changes (Delta A) of leaves from four species in the 500-600 nm range through a Gaussian decomposition, while measuring passively simultaneous Chla fluorescence (F) changes, we present a direct observation of the quick antenna adjustments during a 3-min dark-to-high-light induction. Underlying…