The Millimeter‐ and Submillimeter‐Wave Spectrum of Methyl Carbamate [CH
                    <sub>3</sub>
                    OC(:O)NH
                    <sub>2</sub>
                    ]

Groner, P.; Winnewisser, M.; Medvedev, Ivan R.; Lucia, Frank C. De; Herbst, Eric; Sastry, K. V. L. N.

doi:10.1086/511133

Cited by 37 publications

(49 citation statements)

References 31 publications

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“…For that reason, it has been tentatively searched for in the hot molecular cloud W51e2 and in the intermediate mass protostar IRAS21391+58502 (Demyk et al 2004). Its millimeter and submillimeter wave spectrum has been the object of an in depth study that should now allow this isomer of glycine to be searched for over a wider frequency range (Groner et al 2007). The second conformer of methyl carbamate with significant μ ∼ 5 Debye is 8 kcal/mol higher on the energy scale.…”

Section: Neutral Glycine and Isomersmentioning

confidence: 99%

About the detectability of glycine in the interstellar medium

Lattelais

Pauzat

Pilmé

et al. 2011

A&A

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Context. Glycine, the simplest of aminoacids, has been found in several carbonaceous meteorites. It remains unclear, however, wether glycine is formed in the interstellar medium (ISM) and therefore available everywhere in the Universe. For this reason, radioastronomers have searched for many years unsuccessfully to detect glycine in the ISM. Aims. We provide possible guidelines to optimize the return of these searches. Since, for most of the species observed so far in the ISM, the most abundant isomer of a given generic chemical formula is the most stable one (minimum energy principle (MEP)), we assess whether neutral glycine is the best molecule to search for or whether one of its isomers/conformers or ionic, protonated, or zwitterionic derivatives would have a higher probability of being detected. Methods. The question of the relative stability of these different species is addressed by means of quantum density functional theory (DFT) simulations within the hybrid B3LYP formalism. Each fully optimized structure is verified as a stationary point by means of a vibrational analysis. A comprehensive screening of 32 isomers/conformers of the C 2 H 5 O 2 N chemical formula (neutral, negative, and positive ions together with the corresponding protonated species and the possible zwitterionic structures) is carried out. In the sensitive case of the neutral compounds, more accurate relative energies were obtained by means of high level post Hartree-Fock coupled cluster calculations with large basis sets (CCSD(T)/cc-pVQZ). Results. We find that neutral glycine is not the most stable isomer and, therefore, probably not the most abundant one, which might explain why it has escaped detection so far. We find instead that N-methyl carbamic acid and methyl carbamate are the two most stable isomers and, therefore, probably the two most abundant ones. Among the non-neutral forms, we found that glycine is the most stable isomer only if protonated or zwitterionic if present in interstellar ices. Conclusions. Assuming that MEP can be applied to optimize our search for glycine, our conclusion is that this search will remain extremely difficult with the present instruments and we propose searching instead for other examples among the most stable isomers.

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Section: Neutral Glycine and Isomersmentioning

confidence: 99%

About the detectability of glycine in the interstellar medium

Lattelais

Pauzat

Pilmé

et al. 2011

A&A

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“…Known by the acronym ERHAM, the procedure was developed for a molecule with one or two internal rotors by Groner and collaborators (Groner 1992(Groner , 1997Groner et al 1998), and has been successfully applied to a number of molecules in their ground and excited torsional states, such as dimethyl ether (Groner et al 1998), 3-methyl-1,2-butadiene (Bell et al 2000), acetone (Groner et al 2002, ethyl methyl ether (Fuchs et al 2003), dimethyl diselenide (Groner et al 2004), and acetone-13 C (Lovas & Groner 2006 (Groner et al 2007), which is the NH 2 analog of methyl formate.…”

Section: Effective Hamiltonian For Molecules With Internal Rotationmentioning

confidence: 99%

“…One hundred upward and downward scans were used to average the spectrum to obtain a better signal-to-noise ratio. Frequency shifts due to dispersion caused by water vapor in the ring cavity for calibration were taken into account in the calibration of the spectrum ( Maeda et al 2006;Groner et al 2007). The experimental uncertainty is expected to be better than 100 kHz.…”

Section: Experimental Considerationsmentioning

confidence: 99%

“…This program applies the Loomis-Wood procedure, in which predicted and measured frequencies and intensities of series of related transitions are visually compared, and the comparison is used to make new assignments. For the prediction and global analysis of the ground A and E torsional substates, we used a modified version of the ERHAM program that is compatible with the CAAARS program (Groner et al 2007). Initial predictions were based on the previous submillimeter-wave frequency data for 13 C 1 -methyl formate measured by Willaert et al (2006).…”

Section: Spectral Assignment and Analysis Of The Ground Torsional Statementioning

confidence: 99%

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The Millimeter‐ and Submillimeter‐Wave Spectrum of¹³C₁‐Methyl Formate (H¹³COOCH₃) in the Ground State

Maeda

Medvedev

Lucia

et al. 2008

ASTROPHYS J SUPPL S

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A large number of rotational transitions of 13 C 1 -methyl formate in its ground A and E torsional substates were measured in the 110Y380 GHz region with the Fast Scan Submillimeter Spectroscopic Technique (FASSST). Besides strong a-type transitions, many b-type transitions through rotational quantum numbers J 00 ¼ 59 and K 00 a ¼ 16 were newly measured, and some forbidden c-and x-type transitions in the E substate were also assigned. The new lines were analyzed together with previous submillimeter-wave data using an effective rotational-torsional Hamiltonian method designated ''ERHAM'' developed for a molecule with one or two internal rotors. In total, over 4900 transitions of 13 C 1 -methyl formate were analyzed. Systematic deviations due to perturbations were found in Q-branch transitions at high J, and higher order Coriolis-type interaction terms were included to fit the data better. A standard deviation of 86 kHz was obtained by varying 33 parameters. In addition to 13 C 1 -methyl formate, the normal isotopologue was studied anew and some high-K a transitions were newly assigned. The previous data of the normal species in the ground state were reanalyzed with the ERHAM method together with new transitions measured in the present study. The same deviations in Q-branch transitions, not observed in previous studies, were also found in the normal species. Using spectroscopic parameters obtained in this study, predictions have been made for many strong lines of 13 C 1 -methyl formate through 620 GHz in frequency not analyzed in the fit.

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“…In fact, the microwave spectrum of the carbamic acid has never been recorded. The one of the methyl carbamate, a commercially available compound, has been analyzed [5], but up to now, this compound has never been detected in the ISM. Consequently, if the MEP can be applied, the numerous studies devoted to the detection of glycine in the ISM were really challenging.…”

Section: Methodsmentioning

confidence: 99%

Amino Acids in the Universe

Guillemin

2014

BIO Web of Conferences

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Abstract.What is the role played by amino acids in the chemistry of the interstellar medium and the emergence of life on the early Earth? Are they really the primary key compounds as free amino acids? Is their presence or absence in the interstellar medium a significant problem? How to get an amino acid sample with an enantiomeric excess on the early Earth or ISM? How to increase the enantiomeric excess to have pure enantiomers? All these questions have received partial answers but they remain open and probably they will still be open for several more decades.

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The Millimeter‐ and Submillimeter‐Wave Spectrum of Methyl Carbamate [CH ₃ OC(:O)NH ₂ ]

Cited by 37 publications

References 31 publications

About the detectability of glycine in the interstellar medium

About the detectability of glycine in the interstellar medium

The Millimeter‐ and Submillimeter‐Wave Spectrum of¹³C₁‐Methyl Formate (H¹³COOCH₃) in the Ground State

Amino Acids in the Universe

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The Millimeter‐ and Submillimeter‐Wave Spectrum of Methyl Carbamate [CH 3 OC(:O)NH 2 ]

Cited by 37 publications

References 31 publications

About the detectability of glycine in the interstellar medium

About the detectability of glycine in the interstellar medium

The Millimeter‐ and Submillimeter‐Wave Spectrum of13C1‐Methyl Formate (H13COOCH3) in the Ground State

Amino Acids in the Universe

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The Millimeter‐ and Submillimeter‐Wave Spectrum of Methyl Carbamate [CH ₃ OC(:O)NH ₂ ]

The Millimeter‐ and Submillimeter‐Wave Spectrum of¹³C₁‐Methyl Formate (H¹³COOCH₃) in the Ground State