Gas-phase water-mediated equilibrium between methylglyoxal and its geminal diol.
In aqueous solution, aldehydes, and to a lesser extent ketones, hydrate to form geminal diols. We investigate the hydration of methylglyoxal (MG) in the gas phase, a process not previously considered to occur in water-restricted environments. In this study, we spectroscopically identified methylglyoxal diol (MGD) and obtained the gas-phase partial pressures of MG and MGD. These results, in conjunction with the relative humidity, were used to obtain the equilibrium constant, K(P), for the water-mediated hydration of MG in the gas phase. The Gibbs free energy for this process, DeltaG(o), obtained as a result, suggests a larger than expected gas-phase diol concentration. This may have significant implications for understanding the role of organics in atmospheric chemistry.
Axson
Jessica L
JL
Department of Chemistry and Biochemistry, and Cooperative Institute for Research in Environmental Sciences, Campus Box 215, University of Colorado, Boulder, CO 80309, USA.
Takahashi
Kaito
K
De Haan
David O
DO
Vaida
Veronica
V
D000336:Aerosols / Q000737:chemistry; D000438:Alcohols / Q000737:chemistry*; D002625:Chemistry, Organic / Q000379:methods*; D005740:Gases; D006813:Humidity; D008956:Models, Chemical; D009930:Organic Chemicals / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010313:Partial Pressure; D011312:Pressure; D011765:Pyruvaldehyde / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods; D013816:Thermodynamics; D014732:Vibration; D014867:Water / Q000737:chemistry
D000336:Aerosols; D000438:Alcohols; D005740:Gases; D009930:Organic Chemicals; D014867:Water; D011765:Pyruvaldehyde; D010100:Oxygen