Thermodynamics of the formation of atmospheric organic particulate matter by accretion reactions—2. Dialdehydes, methylglyoxal, and diketones

摘要: Abstract Predicting the formation of organic particulate matter (OPM) in atmosphere by absorptive gas/particle partitioning requires a knowledge identities, atmospheric levels, and physical properties all condensable species. Data from field chamber experiments have shown that portion OPM samples are comprised products generated during oxidation volatile compounds. It has been suggested some these initially formed also contribute to via molecular-weight (MW) building “accretion reactions”. The role such reactions as well general theoretical approach for evaluating their thermodynamic relevance regard formation, discussed prior work. This work utilizes considerations accretion glyoxal, two other dialdehydes, methylglyoxal, diketones. methods used predict free energy ( Δ G f ° ) values (and hence equilibrium constant K values) indicate that: (1) 1,4-butanedial, 2,3-butanedione, 2,5-hexanedione, considered not favorable; (2) C6 higher reaction aldol condensation may under certain circumstances, if kinetically (3) diol subsequent oligomer condensation, thermodynamically favorable, significantly atmosphere, favorable.