Near-infrared laser induced conformational change and UV laser photolysis of glycine in low-temperature matrices: Observation of a short-lived conformer

Bazsó, Gábor; Magyarfalvi, Gábor; Tarczay, György

doi:10.1016/j.molstruc.2012.04.066

Cited by 52 publications

(107 citation statements)

References 73 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In all cases, vapor pressures observed by torsional and gravimetrical method are in reasonable agreement, which strongly supports that no dimerization occurs, although the authors did not mention this fact explicitly. Several different spectroscopic methods were applied to study AAs: microwave, millimeter wave, infrared (IR), UV, mass, and Raman in rare gas matrices at low temperatures and in the vapor phase at both room and elevated temperatures. Even if we focus only on the two smallest amino acids, glycine and alanine, a vast number of references can be listed . Among the reported experimental data, especially rotational constants and O−H and N−H stretching frequencies are very good indicators of occurrence of dimers.…”

Section: Resultsmentioning

confidence: 99%

Volatility Study of Amino Acids by Knudsen Effusion with QCM Mass Loss Detection

et al. 2020

View full text Add to dashboard Cite

This work presents a new Knudsen effusion apparatus employing continuous monitoring of sample deposition using a quartzcrystal microbalance sensor with internal calibration by gravimetric determination of the sample mass loss. The apparatus was tested with anthracene and 1,3,5-triphenylbenzene and subsequently used for the study of sublimation behavior of several proteinogenic amino acids. Their low volatility and thermal instability strongly limit possibilities of studying their sublimation behavior and available literature data. The results presented in this work are unique in their temperature range and low uncertainty required for benchmarking theoretical studies of sublimation behavior of molecular crystals. The possibility of dimerization in the gas phase that would invalidate the effusion experiments is addressed and disproved by theoretical calculations. The enthalpy of sublimation of each amino acid is analyzed based on the contributions in two hypothetical sublimation paths involving the proton transfer in the solid and in the gas phase.[a] Dr.

show abstract

Section: Resultsmentioning

confidence: 99%

Volatility Study of Amino Acids by Knudsen Effusion with QCM Mass Loss Detection

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Ring expansion as aresult of carbon tunneling, as observed in carbenes. [143,151,152] X = Cl,F Angewandte Chemie Reviews proton shifts.T unneling decay of particular conformers of glycine, [166,167] alanine, [168] cytosine, [169] and other small molecules with relevance to biology [170,171] was observed as well as the tunneling-accelerated tautomerization of tetrazole acetic acid. [172] Hydrogen peroxide is chiral if the rotation around the OÀObond is restricted at low temperature.The racemization was investigated by six-dimensional quantum dynamics [173] and shown to proceed efficiently by tunneling.…”

Section: Organic Chemistrymentioning

confidence: 96%

Atom Tunneling in Chemistry

2016

View full text Add to dashboard Cite

Quantum mechanical tunneling of atoms is increasingly found to play an important role in many chemical transformations. Experimentally, atom tunneling can be indirectly detected by temperature-independent rate constants at low temperature or by enhanced kinetic isotope effects. In contrast, the influence of tunneling on the reaction rates can be monitored directly through computational investigations. The tunnel effect, for example, changes reaction paths and branching ratios, enables chemical reactions in an astrochemical environment that would be impossible by thermal transition, and influences biochemical processes.

show abstract

“…However, it has been shown that the combination of steric and hyperconjugative effects, and not IHB, determines glycine, alanine, sarcosine and dimethylglycineconformational energies . Amino acid compounds exhibit a complex conformational isomerism, which complicates the analysis of data extracted from experiments and theoretical calculations . The characterization of the responsible forces that determine amino acid conformational isomerism is not a simple procedure and requires special attention.…”

Section: Introductionmentioning

confidence: 99%

“…The characterization of the responsible forces that determine amino acid conformational isomerism is not a simple procedure and requires special attention. However, the peer‐reviewed literature of conformational analysis of amino acid compounds arbitrarily continues to assume that IHB dictates conformational energies . How could arbitrary assumptions concerning the contribution of the intramolecular forces actuating in these conformational complex compounds be justified?…”

Section: Introductionmentioning

confidence: 99%

A theoretical and experimental¹H NMR spectroscopy study of the stereoelectronic interactions that rule the conformational energies of alanine and valine methyl ester

Cormanich

Ducati

Tormena

et al. 2013

J of Physical Organic Chem

View full text Add to dashboard Cite

Amino acids exhibit a bipolar zwitterionic structure ( + H 3 N-CHR-COO À ) in solution; hence, conformational studies of these compounds have been limited to the gas phase. The conformational preferences of amino acids have been widely attributed to intramolecular hydrogen bonding, despite steric and hyperconjugative effects. In this work, we propose the conformational study of alanine and valine methyl esters, which do not show zwitterionic structures in solution, by 1 H NMR and theoretical calculations. The 3 J HH spin-spin coupling constants and theoretical calculations were found to be in agreement, showing that the interplay between steric hindrance and hyperconjugation is the forces that are responsible for determining the conformational preferences of alanine and valine methyl esters.

show abstract

Near-infrared laser induced conformational change and UV laser photolysis of glycine in low-temperature matrices: Observation of a short-lived conformer

Cited by 52 publications

References 73 publications

Volatility Study of Amino Acids by Knudsen Effusion with QCM Mass Loss Detection

Volatility Study of Amino Acids by Knudsen Effusion with QCM Mass Loss Detection

Atom Tunneling in Chemistry

A theoretical and experimental¹H NMR spectroscopy study of the stereoelectronic interactions that rule the conformational energies of alanine and valine methyl ester

Contact Info

Product

Resources

About

Near-infrared laser induced conformational change and UV laser photolysis of glycine in low-temperature matrices: Observation of a short-lived conformer

Cited by 52 publications

References 73 publications

Volatility Study of Amino Acids by Knudsen Effusion with QCM Mass Loss Detection

Volatility Study of Amino Acids by Knudsen Effusion with QCM Mass Loss Detection

Atom Tunneling in Chemistry

A theoretical and experimental1H NMR spectroscopy study of the stereoelectronic interactions that rule the conformational energies of alanine and valine methyl ester

Contact Info

Product

Resources

About

A theoretical and experimental¹H NMR spectroscopy study of the stereoelectronic interactions that rule the conformational energies of alanine and valine methyl ester