Department of Chemistry and Biochemistry, and Cooperative Institute for Research in Environmental Sciences, Campus Box 215, University of Colorado, Boulder, CO 80309, USA.
Proc Natl Acad Sci U S A. 2010 Apr 13;107(15):6687-92. doi: 10.1073/pnas.0912121107. Epub 2010 Feb 8.
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.
在水溶液中，醛类，在较小程度上还有酮类，会水合形成偕二醇。我们研究了在气相中甲基乙二醛（MG）的水合作用，这一过程以前并未被认为在水受限环境中发生。在这项研究中，我们通过光谱学鉴定了甲基乙二醛二醇（MGD），并获得了 MG 和 MGD 在气相中的分压。这些结果与相对湿度结合使用，得到了气相中水介导的 MG 水合的平衡常数 K(P)。由此得到的这个过程的吉布斯自由能ΔG(o)表明气相中二醇的浓度比预期的要大。这对于理解有机物质在大气化学中的作用可能具有重要意义。
