Photochemistry and Non-adiabatic Photodynamics of the HOSO Radical
6 pags., 2 figs.
Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere.
8 pags., 5 figs., 2 tabs.
Photochemistry of HOSO2 and SO3 and Implications for the Production of Sulfuric Acid
9 pags., 5 figs.
Photodissociation Mechanisms of Major Mercury(II) Species in the Atmospheric Chemical Cycle of Mercury
7 pags., 4 figs.
Multiconfigurational Quantum Chemistry Determinations of Absorption Cross Sections (σ) in the Gas Phase and Molar Extinction Coefficients (ε) in Aqueous Solution and Air–Water Interface
Theoretical determinations of absorption cross sections (σ) in the gas phase and molar extinction coefficients (e) in condensed phases (water solution, interfaces or surfaces, protein or nucleic acids embeddings, etc.) are of interest when rates of photochemical processes, J = ∫ ϕ(λ) σ(λ) I(λ) dλ, are needed, where ϕ(λ) and I(λ) are the quantum yield of the process and the irradiance of the light source, respectively, as functions of the wavelength λ. Efficient computational strategies based on single-reference quantum-chemistry methods have been developed enabling determinations of line shapes or, in some cases, achieving rovibrational resolution. Developments are however lacking for stron…
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 …