A broadband Fourier-transform microwave spectrometer with laser ablation source: The rotational spectrum of nicotinic acid

Mata, Santiago; Peña, Isabel; Cabezas, Carlos; López, Juan C.; Alonso, José L.

doi:10.1016/j.jms.2012.08.004

Cited by 70 publications

(97 citation statements)

References 27 publications

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“…This level of theory has been found to behave satisfactorily in previous studies of several biomolecules. [7][8][9][10]12,13 The results of the calculations at the B3LYP/6-311++G(d,p) level of theory are shown in Table S1 of the ESI. †…”

Section: Resultsmentioning

confidence: 99%

“…Lavrich et al 6 investigated the alanine dipeptide N-acetyl-alanine N 0 -methylamide (Ac-Ala-NHMe) and observed only a C eq 7 conformation using heating methods to bring molecules into the gas phase. Very recently, the combination of FTMW spectroscopic techniques with laser ablation methods [7][8][9][10] has been successfully applied in the investigation of the conformational preferences of isolated protected dipeptides such as N-acetyl-glycinamide (Ac-Gly-NH 2 ), 11 N-acetyl-alaninamide (Ac-Ala-NH 2 ) 12 and N-acetyl-prolinamide (Ac-Pro-NH 2 ). 13 For both Ac-Gly-NH 2 and Ac-Ala-NH 2 , the molecules were found to exist as both the C eq 7 (g-turn) as well as the C 5 (b L -turn) conformation (see Scheme 1), in which the backbones are stabilized by a COÁ Á ÁHN intramolecular hydrogen bond closing a seven-or five-membered ring, respectively.…”

Section: Introductionmentioning

confidence: 99%

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Fourier transform microwave spectroscopy of Ac-Ser-NH₂: the role of side chain interactions in peptide folding

Cabezas

Robben

Rijs

et al. 2015

Phys. Chem. Chem. Phys.

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Serine capped dipeptide N-acetyl-L-serinamide (Ac-Ser-NH 2 ) has been investigated using Fourier transform microwave spectroscopic techniques combined with laser ablation sources. Spectral signatures originating from one dominant species have been detected in the supersonic expansion. Rotational and nuclear quadrupole coupling constants of the two 14 N nuclei have been used in the characterization of a C eq 7 /g-turn structure, which is stabilized by a COÁ Á ÁHN intramolecular hydrogen bond closing a seven-membered ring. Two extra hydrogen bonds involving the polar side chain (-CH 2 OH) further stabilize the structure.The non-observation of C 5 species, attributed to the presence of the polar side chain, is in contrast with the previous gas phase observation of the related dipeptides containing glycine or alanine residues.The A-E splitting pattern arising from the internal rotation of the methyl group has been analyzed and the internal rotation barrier has been determined.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fourier transform microwave spectroscopy of Ac-Ser-NH₂: the role of side chain interactions in peptide folding

Cabezas

Robben

Rijs

et al. 2015

Phys. Chem. Chem. Phys.

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“…To record the rotational spectrum in the 6−18 GHz frequency range, the sample was loaded into the reservoir of two pulsed nozzles and probed by broadband CP-FTMW spectroscopy. Details about the CP-FTMW spectrometer can be found elsewhere (Mata et al 2012). Neon carrier gas at a pressure of 2 bar was used for the pulsed jet expansion.…”

Section: Methodsmentioning

confidence: 99%

Laboratory millimeter wave spectrum and astronomical search for vinyl acetate

Kolesníková

Peña

Alonso

et al. 2015

A&A

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Context. The recent discovery of methyl acetate in Orion KL makes vinyl acetate, CH 3 C=OOCH=CH 2 , a potential molecule in the interstellar medium. We obtained very accurate spectroscopic constants in a comprehensive laboratory analysis of its rotational spectra which can be used to predict those transition frequencies towards interstellar sources. Aims. We present the experimental study and theoretical analysis of the ground torsional state of vinyl acetate in a large spectral range for astrophysical use. Methods. The room-temperature rotational spectrum of vinyl acetate has been measured from 125 to 305 GHz to provide direct frequencies to the astronomical community. Additional measurements have also been made using a broadband CP-FTMW spectrometer in the region of 6−18 GHz. Transition lines, corresponding to the most stable conformer, have been observed and assigned. All the rotational transitions revealed the A-E splitting due to the methyl internal rotation and had to be treated with a specific internal rotation code (BELGI-Cs). Results. We analyzed 2508 transitions up to J = 75 for v t = 0 for the most stable conformer of vinyl acetate. The new lines were globally fitted with previously published data and 24 parameters of the Hamiltonian were accurately determined. The spectral features of vinyl acetate were then searched for in Orion KL. Using the whole line survey of Orion KL (80−280 GHz) obtained with the IRAM 30 m radio telescope we can provide only an upper limit to the column density of vinyl acetate. However, using the ALMA science verification data we obtain a tentative detection of this species that will require further search at other frequencies to confirm its presence in this high mass star forming region.

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“…diverse as neurotransmitters, amino acids, and drugs. [13][14][15] It would be straightforward to modify a pulsed-jet FTMW spectrometer to produce the electric field configuration used here, and our simulations suggest that R-and S-enantiopure samples of a broad class of molecules could be resolved in a single shot on such an instrument. 10 Finally, it is in principal possible to use this technique to determine the absolute configuration (stereochemistry) of a previously unknown molecule.…”

Section: Introductionmentioning

confidence: 99%

Sensitive Chiral Analysis via Microwave Three-Wave Mixing

2013

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We demonstrate chirality-induced three-wave mixing in the microwave regime, using rotational transitions in cold gas-phase samples of 1,2-propanediol and 1,3-butanediol. We show that bulk three-wave mixing, which can only be realized in a chiral environment, provides a sensitive, species selective probe of enantiomeric excess and is applicable to a broad class of molecules. The doubly resonant condition provides simultaneous identification of species and of handedness, which should allow sensitive chiral analysis even within a complex mixture.

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A broadband Fourier-transform microwave spectrometer with laser ablation source: The rotational spectrum of nicotinic acid

Cited by 70 publications

References 27 publications

Fourier transform microwave spectroscopy of Ac-Ser-NH₂: the role of side chain interactions in peptide folding

Fourier transform microwave spectroscopy of Ac-Ser-NH₂: the role of side chain interactions in peptide folding

Laboratory millimeter wave spectrum and astronomical search for vinyl acetate

Sensitive Chiral Analysis via Microwave Three-Wave Mixing

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A broadband Fourier-transform microwave spectrometer with laser ablation source: The rotational spectrum of nicotinic acid

Cited by 70 publications

References 27 publications

Fourier transform microwave spectroscopy of Ac-Ser-NH2: the role of side chain interactions in peptide folding

Fourier transform microwave spectroscopy of Ac-Ser-NH2: the role of side chain interactions in peptide folding

Laboratory millimeter wave spectrum and astronomical search for vinyl acetate

Sensitive Chiral Analysis via Microwave Three-Wave Mixing

Contact Info

Product

Resources

About

Fourier transform microwave spectroscopy of Ac-Ser-NH₂: the role of side chain interactions in peptide folding

Fourier transform microwave spectroscopy of Ac-Ser-NH₂: the role of side chain interactions in peptide folding