0000000000299801

AUTHOR

A. Ulises Acuña

showing 5 related works from this author

A theory ofnonverticaltriplet energy transfer in terms of accurate potential energy surfaces: The transfer reaction from π,π* triplet donors to 1,3,5…

2004

Triplet energy transfer (TET) from aromatic donors to 1,3,5,7-cyclooctatetraene (COT) is an extreme case of "nonvertical" behavior, where the transfer rate for low-energy donors is considerably faster than that predicted for a thermally activated (Arrhenius) process. To explain the anomalous TET of COT and other molecules, a new theoretical model based on transition state theory for nonadiabatic processes is proposed here, which makes use of the adiabatic potential energy surfaces (PES) of reactants and products, as computed from high-level quantum mechanical methods, and a nonadiabatic transfer rate constant. It is shown that the rate of transfer depends on a geometrical distortion paramet…

Arrhenius equationGeneral Physics and AstronomyTriplet stateMolecular configurationsAcceptorPotential energyGround statesUNESCO::FÍSICA::Química físicaCyclooctatetraenechemistry.chemical_compoundsymbols.namesakeTransition state theoryOrganic compounds ; Potential energy surfaces ; Triplet state ; Ground states ; Molecular configurationschemistryPotential energy surfacesOrganic compoundssymbolsMoleculePhysics::Chemical PhysicsPhysical and Theoretical ChemistryTriplet stateAtomic physics:FÍSICA::Química física [UNESCO]Adiabatic processThe Journal of Chemical Physics
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Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere.

2020

8 pags., 5 figs., 2 tabs.

atmospheric chemistryAtmospheric chemistry010504 meteorology & atmospheric sciencesTropospheric chemistryMercury photoreductionchemistry.chemical_elementatmospheric modelingAtmospheric model010501 environmental sciencesPhotochemistry01 natural sciencesTroposphereMercury oxidationComputer SimulationGas-phase mercury reactivitygas-phase mercury reactivity0105 earth and related environmental sciencesmercury photoreductionThermal oxidationMultidisciplinaryAtmospherePhotodissociationCorrectionMercuryModels TheoreticalPhotochemical Processestropospheric chemistryMercury (element)Atmospheric modelingDeposition (aerosol physics)chemistry13. Climate actionAtmospheric chemistry[CHIM.OTHE]Chemical Sciences/OtherOxidation-ReductionProceedings of the National Academy of Sciences of the United States of America
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Photodissociation Mechanisms of Major Mercury(II) Species in the Atmospheric Chemical Cycle of Mercury

2020

7 pags., 4 figs.

Thermal oxidationChemical substance010405 organic chemistryPhotodissociationchemistry.chemical_elementElemental mercuryGeneral MedicineGeneral Chemistry010402 general chemistryPhotochemistry7. Clean energy01 natural sciencesCatalysis0104 chemical sciencesMercury (element)Metalchemistry13. Climate actionvisual_artAtmospheric chemistryThermalvisual_art.visual_art_medium
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Photoreduction of gaseous oxidized mercury changes global atmospheric mercury speciation, transport and deposition

2018

9 pags, 8 figs. -- Correction autor: https://doi.org/10.1038/s41467-022-28455-w http://hdl.handle.net/10261/268181

010504 meteorology & atmospheric sciencesScienceGeneral Physics and Astronomychemistry.chemical_elementAtmospheric mercury010501 environmental sciences01 natural sciences7. Clean energyArticleGeneral Biochemistry Genetics and Molecular Biology14. Life underwaterlcsh:Science0105 earth and related environmental sciencesMultidisciplinaryChemistryAquatic ecosystemQPhotodissociationGeneral ChemistryMercury (element)Earth surface[SDU]Sciences of the Universe [physics]13. Climate actionEnvironmental chemistrySoil waterlcsh:Q
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Gas-Phase Photolysis of Hg(I) Radical Species: A New Atmospheric Mercury Reduction Process

2019

The efficient gas-phase photoreduction of Hg(II) has recently been shown to change mercury cycling significantly in the atmosphere and its deposition to the Earth's surface. However, the photolysis of key Hg(I) species within that cycle is currently not considered. Here we present ultraviolet-visible absorption spectra and cross-sections of HgCl, HgBr, HgI, and HgOH radicals, computed by high-level quantum-chemical methods, and show for the first time that gas-phase Hg(I) photoreduction can occur at time scales that eventually would influence the mercury chemistry in the atmosphere. These results provide new fundamental understanding of the photobehavior of Hg(I) radicals and show that the …

Mercury cyclingAbsorption spectroscopyChemistryRadicalPhotodissociationAtmospheric mercurychemistry.chemical_elementGeneral Chemistry010402 general chemistryPhotochemistry01 natural sciences7. Clean energyBiochemistryCatalysis0104 chemical sciencesGas phaseMercury (element)Colloid and Surface Chemistry13. Climate actionGlobal distribution
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