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.
Department of Chemistry and Biochemistry, and Cooperative Institute for Research in Environmental Sciences, Campus Box 215, University of Colorado, Boulder, CO 80309, USA.
Jessica L
JL
Axson
Kaito
K
Takahashi
David O
DO
De Haan
Veronica
V
Vaida
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