Ultraviolet Spectroscopy of the Gas Phase Hydration of Methylglyoxal

TY - JOUR

T1 - Ultraviolet Spectroscopy of the Gas Phase Hydration of Methylglyoxal

AU - Kroll, Jay A.

AU - Hansen, Anne Schou

AU - Møller, Kristian Holten

AU - Axson, Jessica L.

AU - Kjærgaard, Henrik Grum

AU - Vaida, Veronica

PY - 2017/8/17

Y1 - 2017/8/17

N2 - The gas phase ultraviolet spectrum and stability of 1,1-dihydroxyacetone (the geminal diol of methylglyoxal) are investigated using spectroscopic and computational methods. Experimental gas phase electronic spectra recorded in the ultraviolet-visible range were used to follow the hydration of methylglyoxal. We show that upon the addition of water, methylglyoxal hydrates to form the geminal diol. The electronic spectra of methylglyoxal and its geminal diol conformers were calculated using TD-DFT and LR-CC methods to facilitate experimental peak assignments. The lowest energy electronic transition of the diol is experimentally measured and compared with the results of the theoretical calculations. We find that upon formation of the diol, the lowest-energy transition of methylglyoxal (centered around â430 nm) vanishes, and the remaining transitions, including the methylglyoxal diol absorptions (λmax = 240 nm), fall outside the available solar actinic flux in the troposphere. This likely has significant impacts on the ultimate fate of methylglyoxal in the atmosphere.

AB - The gas phase ultraviolet spectrum and stability of 1,1-dihydroxyacetone (the geminal diol of methylglyoxal) are investigated using spectroscopic and computational methods. Experimental gas phase electronic spectra recorded in the ultraviolet-visible range were used to follow the hydration of methylglyoxal. We show that upon the addition of water, methylglyoxal hydrates to form the geminal diol. The electronic spectra of methylglyoxal and its geminal diol conformers were calculated using TD-DFT and LR-CC methods to facilitate experimental peak assignments. The lowest energy electronic transition of the diol is experimentally measured and compared with the results of the theoretical calculations. We find that upon formation of the diol, the lowest-energy transition of methylglyoxal (centered around â430 nm) vanishes, and the remaining transitions, including the methylglyoxal diol absorptions (λmax = 240 nm), fall outside the available solar actinic flux in the troposphere. This likely has significant impacts on the ultimate fate of methylglyoxal in the atmosphere.

U2 - 10.1021/acsearthspacechem.7b00054

DO - 10.1021/acsearthspacechem.7b00054

M3 - Journal article

SN - 2472-3452

VL - 1

SP - 345

EP - 352

JO - ACS Earth and Space Chemistry

JF - ACS Earth and Space Chemistry

IS - 6

ER -