Amino acetaldehyde conformers: structure and spectroscopic properties

ABSTRACT We present a computational study of the different conformers of amino acetaldehyde. This molecule is a precursor of glycine and also an isomer of the detected molecules acetaldehyde and methylformamide. In addition, a previous theoretical result shows that amino acetaldehyde could be formed from the gas phase reaction of formamide with CH$_{5}^{+}$. Different computational approaches, going from density functional theory (DFT) to coupled cluster (CC) calculations, are employed for the characterization of the amino acetaldehyde conformers. We locate four low-lying conformation on the singlet potential energy surface (PES), two with a synperiplanar arrangement of the carboxylic oxygen atom and the NH2 group, and the other two conformers with an anticlinal disposition. All levels of theory predict the conformer with a synperiplanar arrangement and the H atoms of the NH2 group pointing in the direction of the oxygen, denoted as in-sp-amino acetaldehyde, as the most stable. The viability of the interconversion processes between the four conformers in space is analysed. Relevant spectroscopic parameters to rotational spectroscopy with ‘spectroscopic’ accuracy at the composite level are reported. Vibrational frequencies and infrared intensities are also computed at the CC with single and double excitations (CCSD) level including anharmonic corrections. This information could help in the experimental characterization of amino acetaldehyde that could be considered as a good candidate molecule to be searched for in space.

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Structural and Spectroscopic Characterization of Rhenium Complexes Containing Neutral, Monoanionic, and Dianionic Ligands of 2,2′-Bipyridines and 2,2′:6,2″-Terpyridines: An Experimental and Density Functional Theory (DFT)-Computational Study

Inorganic Chemistry ◽

10.1021/acs.inorgchem.6b00609 ◽

2016 ◽

Vol 55 (10) ◽

pp. 5019-5036 ◽

Cited By ~ 17

Author(s):

Mei Wang ◽

Thomas Weyhermüller ◽

Eckhard Bill ◽

Shengfa Ye ◽

Karl Wieghardt

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Computational Study ◽

Spectroscopic Characterization ◽

Rhenium Complexes ◽

Functional Theory ◽

Dianionic Ligands

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Computational Study of some Double Headed Acyclo-C-Nucleosides

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.61.1 ◽

2015 ◽

Vol 61 ◽

pp. 1-11

Author(s):

Sarah Amara ◽

Noureddine Tchouar ◽

Salah Belaidi

Keyword(s):

Electronic Properties ◽

Ground State ◽

Density Functional ◽

Computational Study ◽

Experimental Studies ◽

Functional Theory ◽

Hartree Fock ◽

Structural And Electronic Properties ◽

Semi Empirical

In the present paper we have a focus in a study of theoretical characterization of three double headed acyclo-C-nucleosides, which are a recent target of experimental studies. The structural and electronic properties of double headed acyclo-C-nucleosides, 1,4-bis (3-mercapto-1H-1,2,4-triazol-5-yl) butane-1,2,3,4-tetrol, 1,4-bis (4-amino-5-mercapto-4H-1,2,4-triazol-3-yl) butane-1,2,3,4-tetrol and 5,5'-(1,2,3,4-tetrahydroxybutane-1,4-diyl) bis (1,3,4-oxadiazole-2(3H)-thione), have been investigated theoretically by performing semi-empirical molecular orbital, ab initio Hartree-Fock (HF) and Density Functional Theory (DFT) calculations. Geometries of the three molecules are optimized at the level of Austin Model 1 (AM1). The electronic properties and relative energies of the molecules have been calculated by HF and DFT in the ground state.

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Structural characterization of kaempferol: a spectroscopic and computational study

Macedonian Journal of Chemistry and Chemical Engineering ◽

10.20450/mjcce.2019.1333 ◽

2019 ◽

Vol 38 (1) ◽

pp. 49 ◽

Cited By ~ 2

Author(s):

Dejan Milenković ◽

Jasmina M Dimitrić Marković ◽

Dušan Dimić ◽

Svetlana Jeremić ◽

Dragan Amić ◽

...

Keyword(s):

Density Functional ◽

Computational Study ◽

Chemical Shifts ◽

Absolute Error ◽

Nbo Analysis ◽

Basis Set ◽

Functional Theory ◽

The Density Functional Theory ◽

Spectroscopic Characteristics

Calculations based on the density functional theory, with the B3LYP functional and the 6-311++G(d,p) basis set, were performed with the aim of confirming the molecular structure and spectroscopic characteristics of kaempferol, a naturally occurring flavonoid molecule. The electronic structure of kaempferol was examined using NBO analysis. The assigning of the experimentally obtained IR and Raman spectra was performed after the best-fit-based comparison with theoretical spectra. The 13C and 1H NMR experimental spectra were related to the theoretically obtained values of the chemical shifts determined by the GIAO method. The correlation coefficient and the average absolute error values proved B3LYP-D3 to be an adequate method in describing the NMR parameters of kaempferol. Molecular docking analysis was carried out in order to identify the potency of inhibition of the title molecule against human procalcitonin. The inhibition activity was obtained for 10 conformations of ligand inside the protein.

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Characterization of β-turns by electronic circular dichroism spectroscopy: a coupled molecular dynamics and time-dependent density functional theory computational study

Physical Chemistry Chemical Physics ◽

10.1039/c9cp05776e ◽

2020 ◽

Vol 22 (3) ◽

pp. 1611-1623

Author(s):

Mattia Migliore ◽

Andrea Bonvicini ◽

Vincent Tognetti ◽

Laure Guilhaudis ◽

Marc Baaden ◽

...

Keyword(s):

Molecular Dynamics ◽

Density Functional Theory ◽

Molecular Dynamics Simulations ◽

Density Functional ◽

Computational Study ◽

Time Dependent ◽

Functional Theory ◽

Dynamics Simulations ◽

Dependent Density

TDDFT coupled with molecular dynamics simulations are used for β-turn characterization by ECD spectroscopy.

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A Novel Approach to the Detection and Characterization of PAH Cations and PAH-Photoproducts

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313016001 ◽

2013 ◽

Vol 9 (S297) ◽

pp. 286-290 ◽

Cited By ~ 3

Author(s):

D. L. Kokkin ◽

A. Simon ◽

C. Marshall ◽

A. Bonnamy ◽

C. Joblin

Keyword(s):

Density Functional ◽

Spectroscopic Properties ◽

Interstellar Space ◽

Functional Theory ◽

Diffuse Interstellar Bands ◽

Novel Approach ◽

Polycyclic Aromatic ◽

Uv Photons ◽

Set Up

AbstractCationic polycyclic aromatic hydrocarbons (PAHs) are attractive candidates for the Diffuse Interstellar Bands, but to date not a single PAH species has been identified on the basis of a spectral agreement. This indicates either that the molecular diversity is very large or that the candidates that have been considered are not the correct ones. In particular, small/medium-sized PAH cations are submitted to photodissociation under UV photons from stars. Therefore it is of interest to characterize the spectroscopic properties of key breakdown products. Furthermore, these studies should be performed under conditions that mimic those found in interstellar space, which leads to additional experimental difficulties. We describe the approach we are developing with the PIRENEA set-up and present results on the 1-Methylpyrene cation and photo-derived species. Experimental measurements are guided by calculations based on density functional theory.

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Atomistic and electronic structure of (X 2 O 3 ) n nanoclusters; n =1–5, X=B, Al, Ga, In and Tl

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2011.0009 ◽

2011 ◽

Vol 467 (2131) ◽

pp. 2020-2042 ◽

Cited By ~ 21

Author(s):

Scott M. Woodley

Keyword(s):

Electronic Structure ◽

Density Functional ◽

Spectroscopic Properties ◽

Interatomic Potentials ◽

Theory Approach ◽

Many Body ◽

Functional Theory ◽

Cation Size ◽

Hybrid Density Functional

The stable and metastable, as measured using an all-electron density functional theory approach, stoichiometric clusters of boron, aluminium, gallium, indium and thallium oxide are reported. Initial candidate structures were found using an evolutionary algorithm to search the energy landscape, defined using classical interatomic potentials, for alumina and india followed by data mining or rescaling. Characterization of the refined structures was performed by electronic structure techniques at the hybrid density functional and many-body GW levels of theory. We make accurate predictions of the spectroscopic properties represented by mean ionization potentials of 11.4, 9.9, 9.8, 8.8 and 8.4 eV and electron affinities of 0.05, 1.1, 1.6, 1.9 and 2.5 eV for boria, alumina, gallia, india and thallia, respectively. The changes in the global minima, atomistic and electronic properties with respect to the cluster and cation size are discussed.

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Computational Study of the Electron Spectra of Vapor-Phase Indole and Four Azaindoles

Molecules ◽

10.3390/molecules26071947 ◽

2021 ◽

Vol 26 (7) ◽

pp. 1947

Author(s):

Delano P. Chong

Keyword(s):

Density Functional Theory ◽

Vapor Phase ◽

Density Functional ◽

Computational Study ◽

Geometry Optimization ◽

The Other ◽

Functional Theory ◽

Electron Spectra

After geometry optimization, the electron spectra of indole and four azaindoles are calculated by density functional theory. Available experimental photoemission and excitation data for indole and 7-azaindole are used to compare with the theoretical values. The results for the other azaindoles are presented as predictions to help the interpretation of experimental spectra when they become available.

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A computational study for the reaction mechanism of metal-free cyanomethylation of aryl alkynoates with acetonitrile

RSC Advances ◽

10.1039/d1ra01649k ◽

2021 ◽

Vol 11 (30) ◽

pp. 18246-18251

Author(s):

Selçuk Eşsiz

Keyword(s):

Density Functional Theory ◽

Reaction Mechanism ◽

Density Functional ◽

Computational Study ◽

Coupled Cluster ◽

Functional Theory ◽

Metal Free ◽

Coupled Cluster Methods ◽

High Level ◽

Cluster Methods

A computational study of metal-free cyanomethylation and cyclization of aryl alkynoates with acetonitrile is carried out employing density functional theory and high-level coupled-cluster methods, such as [CCSD(T)].

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Unraveling the electrochemical and spectroscopic properties of neutral and negatively charged perylene tetraethylesters

Scientific Reports ◽

10.1038/s41598-021-95551-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Christian Wiebeler ◽

Joachim Vollbrecht ◽

Adam Neuba ◽

Heinz-Siegfried Kitzerow ◽

Stefan Schumacher

Keyword(s):

Absorption Spectra ◽

Density Functional ◽

Energy Levels ◽

Spectroscopic Properties ◽

Absorption Bands ◽

Functional Theory ◽

Vertical Excitation ◽

Hartree Fock ◽

Tauc Plot ◽

Electrochemical Approach

AbstractA detailed investigation of the energy levels of perylene-3,4,9,10-tetracarboxylic tetraethylester as a representative compound for the whole family of perylene esters was performed. It was revealed via electrochemical measurements that one oxidation and two reductions take place. The bandgaps determined via the electrochemical approach are in good agreement with the optical bandgap obtained from the absorption spectra via a Tauc plot. In addition, absorption spectra in dependence of the electrochemical potential were the basis for extensive quantum-chemical calculations of the neutral, monoanionic, and dianionic molecules. For this purpose, calculations based on density functional theory were compared with post-Hartree–Fock methods and the CAM-B3LYP functional proved to be the most reliable choice for the calculation of absorption spectra. Furthermore, spectral features found experimentally could be reproduced with vibronic calculations and allowed to understand their origins. In particular, the two lowest energy absorption bands of the anion are not caused by absorption of two distinct electronic states, which might have been expected from vertical excitation calculations, but both states exhibit a strong vibronic progression resulting in contributions to both bands.

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