| This investigation focuses on the chemical and photochemical reactivity, structure, bonding, stability, abundance, spectroscopy, and relative atmospheric importance of some novel atmospheric absorbers. Specifically, laboratory and computational studies have been used to examine the atmospheric relevance of near-infrared alkylperoxy (RO2) photochemistry, to investigate the spectroscopy, physicochemical properties, and the atmospheric role of select hydrated molecular complexes, to characterize the infrared and overtone spectroscopy of vapor phase formic and acetic acid, and to explore the formation of HCOOH-H2O and CH3COOH-H2O at equilibrium conditions. Fourier transform spectroscopy (FTS) was used to probe the alkylperoxy à 2A′ ← X˜ 2A″ electronic transition in order to measure the absorption cross-section of this near-infrared transition and evaluate the tropospheric implications of near-IR RO2 photolysis. It has been proposed that this transition could result in an RO2 electron configuration that facilitates intramolecular rearrangement and subsequent photodissociation into a variety of photoproducts, including OH, HO2 and a host of possible aldehydes, ketones and alkenes. Equilibrium thermodynamics were used to investigate the abundance and atmospheric role of O2-H2O, N2-H2O, Ar-H2 O, CO2-H2O, O3-H2O, H 2O-H2O, HNO3-H2O, HCOOH-H2O, CH3COOH-H2O and higher-order water clusters. The effect that monomer concentrations, temperature, and binding energies have on these calculated abundances and the competition which arises between entropy and energy at atmospherically-relevant temperatures are discussed. Fourier transform spectroscopy was used to measure the infrared and overtone spectroscopy of vapor-phase organic acids and investigate the formation of HCOOH-H2O and CH3COOH-H2O in equilibrium cells and supersonic jet expansions. |
