Vibrational energy distributions in co2 produced in laser-induced infrared multiphoton reactions: the decarboxylation of vinyl acetic and pyruvic acids

Buechele, James L.; Weitz, Eric; Lewis, Frederick D.

doi:10.1016/0009-2614(81)80146-7

Cited by 12 publications

(12 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, organic peroxides, ROOH, could rearrange to RH + O 2 following overtone excitation of the OH bond. Dicarboxylic acids are known to decarboxylate thermally 54 and via infrared MPD, 55,56 with activation energies similar to those expected for lower overtone transitions. If lower overtone excitation effects decarboxylation in these compounds, the resulting lifetimes could be on the order of days, and this mechanism might compete with rainout for their removal.…”

Section: Other Moleculesmentioning

confidence: 77%

Atmospheric Photochemistry via Vibrational Overtone Absorption

2003

View full text Add to dashboard Cite

Section: Other Moleculesmentioning

confidence: 77%

Atmospheric Photochemistry via Vibrational Overtone Absorption

2003

View full text Add to dashboard Cite

“…Pyruvic acid is known to readily undergo photodecomposition and its mechanism is found to be the unimolecular decarboxylation. − In view of the limited stability of the compound, we paid special attention to experimental conditions. For preparation of the matrices of pyruvic acid we employed a technique similar to that previously used to prepare samples of matrix-isolated formic acid .…”

Section: Methodsmentioning

confidence: 99%

“…Pyruvic acid is known to readily undergo photodecomposition and its mechanism is found to be the unimolecular decarboxylation. [18][19][20][21][22][23] In view of the limited stability of the compound, we paid special attention to experimental conditions. For preparation of the matrices of pyruvic acid we employed a technique similar to that previously used to prepare samples of matrix-isolated formic acid.…”

Section: Methodsmentioning

confidence: 99%

Combined FTIR Matrix Isolation and Ab Initio Studies of Pyruvic Acid: Proof for Existence of the Second Conformer

et al. 2001

View full text Add to dashboard Cite

The molecular structure of pyruvic acid was investigated by matrix isolation FTIR spectroscopy, density functional theory (DFT), and ab initio calculations performed at the RHF, MP2, MP4(SDQ), and CCSD(T) levels of theory with the aug-cc-pVDZ basis set. In these calculations, the geometries of the three lowest energy conformers of pyruvic acid were fully optimized at the DFT/B3LYP/aug-cc-pVDZ and MP2/aug-ccpVDZ levels. Additionally, the relative energies of the conformers were calculated at the MP4, CCSD, and CCSD(T) levels. Harmonic frequencies and IR intensities were then calculated for these three conformers and were used to account for the zero point vibrational energy corrections and to assist the assignment of the observed bands to the different forms. We found that two conformers are present in the Ar matrix, and both forms exhibit a planar framework with the carbonyl bonds in a trans arrangement but differ in the orientation of the hydroxyl hydrogen. By varying the temperature of the pyruvic acid vapor prior to matrix deposition we were able to separate the bands due to the two conformers and measure their enthalpy difference. The spectral signature of the second pyruvic acid conformer has been identified for the first time. Experimental enthalpy difference between the two most stable conformers was found to be 8.7((15%) kJ mol -1 , which is in good agreement with the theoretical result.

show abstract

“…Pyruvic acid is abundant in the atmosphere both in the gas phase and in aerosols as it is an oxidative product of isoprene. − Pyruvic acid has been used as a proxy for modeling the behavior of other atmospheric α-dicarbonyls. , Solutions of pyruvic acid have been used as a model for organic aerosol matter . Pyruvic acid can be decarboxylated with UV excitation, ,,− thermally, ,,,, and through infrared multiphoton pyrolysis. − Recent gas-phase experimental and theoretical results suggest that pyruvic acid should be the ideal model system to use for the experimental observation of the vibrational overtone initiated photochemical reaction of α-dicarbonyls. ,, In gas-phase pyruvic acid experiments, significant spectral broadening was observed for the excitation of the third (Δν OH = 4) and fourth (Δν OH = 5) overtone of the lowest energy conformer of pyruvic acid. ,, Theoretical results helped assign this broadening as being due the initiation of a concerted reaction of pyruvic acid, where two covalent bonds are broken simultaneously at energies below the bond dissociation energy. ,, The predicted photoproducts are CO 2 and methylhydroxycarbene. , However, due to the low density of pyruvic acid molecules in the gas phase and the low absorption cross sections of the overtones, the formation of CO 2 and other organic photoproducts were not experimentally observed.…”

Section: Introductionmentioning

confidence: 99%

Near Infrared Photochemistry of Pyruvic Acid in Aqueous Solution

Larsen

Vaida

2012

J. Phys. Chem. A

View full text Add to dashboard Cite

Recent experimental and theoretical results have suggested that organic acids such as pyruvic acid, can be photolyzed in the ground electronic state by the excitation of the OH stretch vibrational overtone. These overtones absorb in the near-infrared and visible regions of the spectrum where the solar photons are plentiful and could provide a reaction pathway for the organic acids and alcohols that are abundant in the earth's atmosphere. In this paper the overtone initiated photochemistry of aqueous pyruvic acid is investigated by monitoring the evolution of carbon dioxide. In these experiments CO(2) is being produced by excitation in the near-infrared, between 850 nm and ∼1150 nm (11,765-8696 cm(-1)), where the second OH vibrational overtone (Δν = 3) of pyruvic acid is expected to absorb. These findings show not only that the overtone initiated photochemical decarboxylation reaction occurs but also that in the aqueous phase it occurs at a lower energy than was predicted for the overtone initiated reaction of pyruvic acid in the gas phase (13,380 cm(-1)). A quantum yield of (3.5 ± 1.0) × 10(-4) is estimated, suggesting that although this process does occur, it does so with a very low efficiency.

show abstract

Vibrational energy distributions in co2 produced in laser-induced infrared multiphoton reactions: the decarboxylation of vinyl acetic and pyruvic acids

Cited by 12 publications

References 21 publications

Atmospheric Photochemistry via Vibrational Overtone Absorption

Atmospheric Photochemistry via Vibrational Overtone Absorption

Combined FTIR Matrix Isolation and Ab Initio Studies of Pyruvic Acid: Proof for Existence of the Second Conformer

Near Infrared Photochemistry of Pyruvic Acid in Aqueous Solution

Contact Info

Product

Resources

About