scholarly journals ACCURATE CHARACTERIZATION OF THE PEPTIDE LINKAGE IN THE GAS PHASE: A JOINT QUANTUM-CHEMICAL AND ROTATIONAL SPECTROSCOPY STUDY OF THE GLYCINE DIPEPTIDE ANALOGUE

2014 ◽  
Author(s):  
Cristina Puzzarini ◽  
José Alonso ◽  
Carlos Cabezas ◽  
Isabel Peña ◽  
Laura Largo ◽  
...  
Keyword(s):  
Gas Phase ◽  
Quantum Chemical ◽  
Rotational Spectroscopy ◽  
Spectroscopy Study ◽  
Peptide Linkage

Accurate Characterization of the Peptide Linkage in the Gas Phase: A Joint Quantum-Chemical and Rotational Spectroscopy Study of the Glycine Dipeptide Analogue

2014 ◽  
Vol 5 (3) ◽  
pp. 534-540 ◽  
Author(s):  
Cristina Puzzarini ◽  
Malgorzata Biczysko ◽  
Vincenzo Barone ◽  
Laura Largo ◽  
Isabel Peña ◽  
...  
Keyword(s):  
Gas Phase ◽  
Quantum Chemical ◽  
Rotational Spectroscopy ◽  
Spectroscopy Study ◽  
Peptide Linkage

scholarly journals Generation and structural characterization of Ge carbides GeCn (n = 4, 5, 6) by laser ablation, broadband rotational spectroscopy, and quantum chemistry

2019 ◽  
Vol 21 (35) ◽  
pp. 18911-18919
Author(s):  
Kin Long Kelvin Lee ◽  
Sven Thorwirth ◽  
Marie-Aline Martin-Drumel ◽  
Michael C. McCarthy
Keyword(s):  
Fourier Transform ◽  
Laser Ablation ◽  
Structural Characterization ◽  
Quantum Chemical ◽  
Microwave Spectroscopy ◽  
Rotational Spectroscopy ◽  
Chirped Pulse ◽  
Rotational Spectra ◽  
High Level

Rotational spectra of three Ge carbides, linear GeC4, GeC5, and GeC6 have been observed using chirped pulse and cavity Fourier transform microwave spectroscopy via laser ablation, guided by new high-level quantum chemical calculations.

scholarly journals Thermodynamics of reactions of ClHg and BrHg radicals with atmospherically abundant free radicals

2012 ◽  
Vol 12 (7) ◽  
pp. 17887-17911
Author(s):  
T. S. Dibble ◽  
M. J. Zelie ◽  
H. Mao
Keyword(s):  
Gas Phase ◽  
Quantum Chemical ◽  
Molecular Level ◽  
Elemental Mercury ◽  
Published Data ◽  
Quantum Calculations ◽  
Laboratory Studies ◽  
Gaseous Elemental Mercury ◽  
The Stability

Abstract. Quantum calculations are used to determine the stability of reactive gaseous mercury (Hg(II)) compounds likely to be formed in the Br-initiated oxidation of gaseous elemental mercury (Hg(0)). Due to the absence of any evidence, current models neglect the possible reaction of BrHg• with abundant radicals such as NO, NO2, HO2, ClO, or BrO. The present work demonstrates that BrHg• forms stable compounds, BrHgY, with all of these radicals except NO. Additional calculations on the analogous ClHgY compounds reveal that the strength of the XHg-Y bond (for X=Cl, Br) varies little with the identity of the halogen. Calculations further suggest that ClO, BrO, and NO3 do not form strong bonds with Hg(0), and cannot initiate Hg(0) oxidation in the gas phase. The theoretical approach is validated by comparison to published data on HgX2 compounds, both from experiments and highly refined quantum chemical calculations. Quantum calculations on the stability of the anions of XHgY are carried out in order to aid future laboratory studies aimed at molecular-level characterization of gaseous Hg(II) compounds. Spectroscopic data on BrHg• are analyzed to determine the equilibrium constant for its formation, and BrHg• is determined to be much less stable than previously estimated. An expression is presented for the rate constant for BrHg• dissociation.

The Generation of Low-Valence Tin Derivatives, RSn(I), in the Gas-Phase by Neutralization—reionization Mass Spectrometry

2002 ◽  
Vol 8 (5) ◽  
pp. 351-357 ◽  
Author(s):  
Dmitri Zagorevskii ◽  
Yang Yuan ◽  
C. Michael Greenlief ◽  
Alexander A. Mommers
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Quantum Chemical Calculations ◽  
Molecular Species ◽  
Quantum Chemical ◽  
Mass Spectra ◽  
Stable Species ◽  
The Stability ◽  
Franck Condon

Neutralization-reionization mass spectrometry (NRMS) was applied to the generation and characterization of low-valence Sn(I) derivatives. The observation of recovery signals in the NR mass spectra of RSn+ ions (R=H, Cl, Br, CH3, C2H, C6H5) demonstrated that their neutral counterparts are stable species in the gas-phase with a lifetime of at least 5 μs. According to quantum chemical calculations, a favorable Franck–Condon factor may contribute to the stability of RSn neutrals generated in the NR event. The experimental results for tin acetylide and phenyltin are the first examples of the generation of these previously unknown molecular species.

ChemInform Abstract: Characterization of cis- and trans-HSSOH via Rotational Spectroscopy and Quantum-Chemical Calculations.

ChemInform ◽  
2009 ◽  
Vol 40 (22) ◽  
Author(s):  
Monika Koerber ◽  
Oliver Baum ◽  
Thomas F. Giesen ◽  
Stephan Schlemmer ◽  
Josef Hahn ◽  
...  
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Rotational Spectroscopy ◽  
Abstract Characterization ◽  
Cis And Trans

scholarly journals Quantum Chemical Characterization of Low-Energy States of Calicene in the Gas Phase and in Solution

2007 ◽  
Vol 72 (8) ◽  
pp. 2823-2831 ◽  
Author(s):  
Giovanni Ghigo ◽  
Abdul Rehaman Moughal Shahi ◽  
Laura Gagliardi ◽  
Lee M. Solstad ◽  
Christopher J. Cramer
Keyword(s):  
Gas Phase ◽  
Quantum Chemical ◽  
Chemical Characterization ◽  
Low Energy ◽  
Energy States

scholarly journals Anharmonic Vibrational Frequencies of Water Borane and Associated Molecules

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7348
Author(s):  
Brent R. Westbrook ◽  
Ryan C. Fortenberry
Keyword(s):  
Experimental Data ◽  
Gas Phase ◽  
Vibrational Spectra ◽  
Quantum Chemical ◽  
Hydrogen Generation ◽  
Vibrational Frequencies ◽  
Rotational Spectroscopy ◽  
Vibrational Modes ◽  
Theoretical Predictions ◽  
Borinic Acid

Water borane (BH3OH2) and borinic acid (BH2OH) have been proposed as intermediates along the pathway of hydrogen generation from simple reactants: water and borane. However, the vibrational spectra for neither water borane nor borinic acid has been investigaged experimentally due to the difficulty of isolating them in the gas phase, making accurate quantum chemical predictions for such properties the most viable means of their determination. This work presents theoretical predictions of the full rotational and fundamental vibrational spectra of these two potentially application-rich molecules using quartic force fields at the CCSD(T)-F12b/cc-pCVTZ-F12 level with additional corrections included for the effects of scalar relativity. This computational scheme is further benchmarked against the available gas-phase experimental data for the related borane and HBO molecules. The differences are found to be within 3 cm−1 for the fundamental vibrational frequencies and as close as 15 MHz in the B0 and C0 principal rotational constants. Both BH2OH and BH3OH2 have multiple vibrational modes with intensities greater than 100 km mol−1, namely ν2 and ν4 in BH2OH, and ν1, ν3, ν4, ν9, and ν13 in BH3OH2. Finally, BH3OH2 has a large dipole moment of 4.24 D, which should enable it to be observable by rotational spectroscopy, as well.

scholarly journals Thermodynamics of reactions of ClHg and BrHg radicals with atmospherically abundant free radicals

2012 ◽  
Vol 12 (21) ◽  
pp. 10271-10279 ◽  
Author(s):  
T. S. Dibble ◽  
M. J. Zelie ◽  
H. Mao
Keyword(s):  
Gas Phase ◽  
Quantum Chemical ◽  
Molecular Level ◽  
Elemental Mercury ◽  
Published Data ◽  
Quantum Calculations ◽  
Laboratory Studies ◽  
Gaseous Elemental Mercury ◽  
The Stability

Abstract. Quantum calculations are used to determine the stability of reactive gaseous mercury (Hg(II)) compounds likely to be formed in the Br-initiated oxidation of gaseous elemental mercury (Hg(0)). Due to the absence of any evidence, current models neglect the possible reaction of BrHg with abundant radicals such as NO, NO2, HO2, ClO, or BrO. The present work demonstrates that BrHg forms stable compounds, BrHgY, with all of these radicals except NO. Additional calculations on the analogous ClHgY compounds reveal that the strength of the XHg-Y bond (for X = Cl, Br) varies little with the identity of the halogen. Calculations further suggest that HO2 and NO3 do not form strong bonds with Hg(0), and cannot initiate Hg(0) oxidation in the gas phase. The theoretical approach is validated by comparison to published data on HgX2 compounds, both from experiment and highly refined quantum chemical calculations. Quantum calculations on the stability of the anions of XHgY are carried out in order to aid future laboratory studies aimed at molecular-level characterization of gaseous Hg(II) compounds. Spectroscopic data on BrHg is analyzed to determine the equilibrium constant for its formation, and BrHg is determined to be much less stable than previously estimated. An expression is presented for the rate constant for BrHg dissociation.

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