0000000000299801
AUTHOR
A. Ulises Acuña
A theory ofnonverticaltriplet energy transfer in terms of accurate potential energy surfaces: The transfer reaction from π,π* triplet donors to 1,3,5,7-cyclooctatetraene
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…
Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere.
8 pags., 5 figs., 2 tabs.
Photodissociation Mechanisms of Major Mercury(II) Species in the Atmospheric Chemical Cycle of Mercury
7 pags., 4 figs.
Photoreduction of gaseous oxidized mercury changes global atmospheric mercury speciation, transport and deposition
9 pags, 8 figs. -- Correction autor: https://doi.org/10.1038/s41467-022-28455-w http://hdl.handle.net/10261/268181
Gas-Phase Photolysis of Hg(I) Radical Species: A New Atmospheric Mercury Reduction Process
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 …