New measurements of the microwave spectrum of formamide

Kryvda, A.V.; Gerasimov, V. G.; Dyubko, S. F.; Alekseev, E. A.; Motiyenko, R. A.

doi:10.1016/j.jms.2008.12.001

Cited by 32 publications

(25 citation statements)

References 11 publications

(28 reference statements)

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“…These tests were also important in choosing a correct set of octic centrifugal distortion parameters. Compared to the last study we found that the non-diagonal octic parameter of the A-reduction l K determined previously (Kryvda et al 2009) deteriorates the conditionality of the fit. This can lead to large errors in predicting the transition frequencies, which are sensitive to this parameter.…”

Section: Methodscontrasting

confidence: 90%

“…In our measurements, hyperfine splittings were observed for some weak b-type transitions even at 850 GHz. The assignment process based on predictions available from recent studies (Kryvda et al 2009) was rather straightforward and did not present any major difficulties. Relatively small deviations from the predicted frequencies were only observed for high K a transitions of normal isotopologue and high J transitions of 13 C species.…”

Section: Methodsmentioning

confidence: 99%

“…Several subsequent studies (Kirchhoff & Johnson 1973;Hirota et al 1974;Moskienko & Dyubko 1991;Vorob'eva & Dyubko 1994) have extended the measurements into the sub-millimeter wave range up to 445 GHz for the ground and first excited vibrational state ν 12 . The recent paper by Kryvda et al (2009) presents a new revision of all previous results as well as new spectroscopic data on normal, 13 C, 15 N, and 18 O isotopic species of formamide in the frequency range up to 250 GHz. are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/548/A71…”

Section: Introductionmentioning

confidence: 96%

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Rotational spectrum of formamide up to 1 THz and first ISM detection of itsν₁₂vibrational state

Motiyenko

Tercero

Cernicharo

et al. 2012

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Context. Formamide is the simplest bearer of peptide bond detected in the interstellar medium (ISM). Aims. There is still a lack of laboratory data on its rotational spectrum in the THz domain. Methods. We measured the rotational spectrum of formamide in the frequency range 400-950 GHz. The ground and first excited vibrational state of the normal species as well as the ground state of 13 C isotopic species were analysed. Results. The results obtained represent an extension by a factor of two in frequency range compared to previous studies. Of all transition frequencies in the dataset about 45% are new measurements. A reliable set of rotational constants allows accurate predictions of transition frequencies in the THz domain. Based on the spectroscopic results, the ν 12 = 1 excited vibrational state of formamide was detected in the IRAM 30 m line survey of Orion KL for the first time in the ISM.

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Section: Methodscontrasting

confidence: 90%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

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Rotational spectrum of formamide up to 1 THz and first ISM detection of itsν₁₂vibrational state

Motiyenko

Tercero

Cernicharo

et al. 2012

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“…To simplify the initial assignment, the first frequency predictions of each deuterated species were calculated using the corresponding rotational rigid rotor constants A, B, C from (Costain & Dowling 1960) and the quartic centrifugal distortion constants from parent species (Kryvda et al 2009). Such a combination of parameters was good enough to assign low-J a R 0,1 transitions in 150-200 GHz frequency range.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore its rotational spectrum extends in the terahertz range even under the low-temperature conditions of the interstellar medium. The rotational spectrum of the parent species of formamide has been extensively studied up to 1 THz (Kryvda et al 2009;Motiyenko et al 2012). The available data on its deuterated isotopologue are much more limited.…”

Section: Introductionmentioning

confidence: 99%

The extended spectroscopic database for deuterated species of formamide up to 1 THz

Kutsenko

Motiyenko

Margulès

et al. 2013

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Context. Formamide (HCONH 2 ) is the simplest molecule with a peptide bond detected in the interstellar medium. One of the keys for understanding the mechanisms for forming formamide in massive hot cores is the comparison of the relative abundances of its deuterated isotopologues. Aims. No deuterated species of formamide have been detected to date mostly owing to the lack of laboratory spectral data, which is limited by cm-wave measurements up to 40 GHz. Therefore, we decided to extend the measurements and the analysis of the rotational spectra of deuterated istopologues of formamide into the terahertz range. Methods. We measured the rotational spectra of deuterated formamide in the frequency range 150-950 GHz using the Lille fast-scan and solid-state source spectrometers. Results. The ground vibrational states of 4 different isotopologues of formamide, DCONH 2 , cis-HCONHD, trans-HCONHD, and HCOND 2 , were assigned and analysed. The sets of the rotational and centrifugal distortion constants we obtained allow us to calculate accurate predictions of the transition frequencies for deuterated formamide in the frequency range above 1 THz and at least for J < 65 and K a < 25.

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Modeling of structures and calculation of IR vibrational spectra of N,N-dimethylformamide dimers by density functional theory

et al. 2011

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UDC 539.19We present results of ab initio and DFT calculations of the structure and IR vibrational spectra of the monomer and dimers of N,N-dimethylformamide (DMF). The calculations were carried out in the B3LYP/cc-pVDZ approximation with subsequent force-field scaling. The calculated characteristics of the vibrational spectra of DMF show satisfactory agreement with experimental values, allowing them to be used in spectral and structural analysis.Introduction. Dimethylformamide (DMF) is one of the simplest amides and has several interesting properties. DMF does not contain an NH group, which is responsible for the nature of the intermolecular structure formed by this compound in the condensed state. The methyl and aldehyde groups act as proton donors in forming dimeric and polymeric structures of DMF. Therefore, in contrast with the closest analogs of DMF, formamide (FA) and methylformamide (MFA), the molecular clusters of DMF that are formed in the liquid phase have comparatively weak binding energies and vibrational spectra that are unperturbed by the effect of strong H-bonds. Thus, DMF is a convenient subject for studying the structural and spectral characteristics of molecular systems that are important from biological and technical viewpoints. Furthermore, liquid DMF is an important aprotic dipolar solvent. DMF often fulfills the role of an organic ligand in complexes with ions and compounds of various metals owing to the presence in it of the carbonyl.The molecular structure and vibrational spectra of DMF were studied several times both experimentally [1-9] and theoretically [7,8,[10][11][12]. However, the question of whether the molecular skeleton is planar or non-planar has not yet been answered. Also, the low symmetry of the molecule is responsible for significant interactions between vibrational modes. This causes definite difficulties in assigning vibrational bands and lines. Therefore, vibrational spectra of monomeric and dimeric forms of DMF have also not been conclusively interpreted.Herein results of quantum-chemical calculations of the structure and energy and spectral characteristics of DMF monomer and dimers are presented. Experimental IR absorption spectra are interpreted. Vibrational spectra of DMF are modeled in the gas and liquid phases.Experimental. IR absorption spectra of DMF were recorded in the range 400-4000 cm -1 on a Bruker Vertex 70 spectrophotometer. The first sample was prepared as a solution of DMF in CCl 4 (0.05 M). The second sample was pure DMF. IR spectra of the samples were recoded in a KBr cuvette (0.05 mm).Calculations. Structural and spectral characteristics of DMF monomer and dimers were calculated using the applied quantum-chemical program GAMESS [13,14]. The results were visualized using the MacMolPlt program [15]. The standard basis sets cc-pVDZ and cc-pVTZ [16], DFT methods, and the hybrid functional B3LYP [17][18][19] were utilized to optimize the equilibrium structure and calculate the force field and harmonic vibrational eigenfrequencies and intensities in IR spec...

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New measurements of the microwave spectrum of formamide

Cited by 32 publications

References 11 publications

Rotational spectrum of formamide up to 1 THz and first ISM detection of itsν₁₂vibrational state

Rotational spectrum of formamide up to 1 THz and first ISM detection of itsν₁₂vibrational state

The extended spectroscopic database for deuterated species of formamide up to 1 THz

Modeling of structures and calculation of IR vibrational spectra of N,N-dimethylformamide dimers by density functional theory

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New measurements of the microwave spectrum of formamide

Cited by 32 publications

References 11 publications

Rotational spectrum of formamide up to 1 THz and first ISM detection of itsν12vibrational state

Rotational spectrum of formamide up to 1 THz and first ISM detection of itsν12vibrational state

The extended spectroscopic database for deuterated species of formamide up to 1 THz

Modeling of structures and calculation of IR vibrational spectra of N,N-dimethylformamide dimers by density functional theory

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Product

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Rotational spectrum of formamide up to 1 THz and first ISM detection of itsν₁₂vibrational state

Rotational spectrum of formamide up to 1 THz and first ISM detection of itsν₁₂vibrational state