Precise Laboratory Measurements of Trans-Dcooh and Trans-Hcood for Astrophysical Observations

Cazzoli, G.; Puzzarini, Cristina; Stopkowicz, Stella; Gauß, Jürgen

doi:10.1088/0067-0049/196/1/10

Cited by 7 publications

(8 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Baselines in the spectra were all fitted by constant functions, or polynomials of order 1. The rest frequencies used for the line identification, have been taken from different laboratory works: HC 15 N from Cazzoli et al (2005), H 13 CN from Cazzoli & Puzzarini (2006), HN 13 C from van der Tak et al ( 2009), H 15 NC from Pearson et al (1976) and DNC from Bechtel et al (2006). The other spectroscopic parameters used in the derivation of the column densities have been taken from the Cologne Molecular Database for Spectroscopy 2 (CDMS; Müller et al 2001Müller et al , 2005 except for H 15 NC, for which we have used the Jet Propulsion Laboratory database 3 .…”

Section: Observationsmentioning

confidence: 99%

Nitrogen and hydrogen fractionation in high-mass star-forming cores from observations of HCN and HNC

Colzi

Fontani

Caselli

et al. 2018

A&A

View full text Add to dashboard Cite

The ratio between the two stable isotopes of nitrogen, 14 N and 15 N, is well measured in the terrestrial atmosphere (∼ 272), and for the pre-Solar nebula (∼ 441, deduced from the Solar wind). Interestingly, some pristine Solar System materials show enrichments in 15 N with respect to the pre-Solar nebula value. However, it is not yet clear if, and how, these enrichments are linked to the past chemical history, due to the limited number of measurements in dense star-forming regions. In this respect, dense cores believed to be precursors of clusters containing also intermediate-and high-mass stars are important targets, as the Solar System was probably born within a rich stellar cluster. The number of observations in such high-mass dense cores has remained limited so far. In this work, we show the results of IRAM-30m observations of the J=1-0 rotational transition of the molecules HCN and HNC, and their 15 N-bearing counterparts, towards 27 intermediate/high-mass dense cores divided almost equally in three evolutionary categories: high-mass starless cores, high-mass protostellar objects, and ultra-compact Hii regions. We have also observed the DNC(2-1) rotational transition, in order to search for a relation between the isotopic ratios D/H and 14 N/ 15 N. We derive average 14 N/ 15 N ratios of 359±16 in HCN and of 438±21 in HNC, with a dispersion of about 150-200. We find no trend of the 14 N/ 15 N ratio with the evolutionary stage. This result agrees with what found from N 2 H + and its isotopologues in the same sources, although the 14 N/ 15 N ratios from N 2 H + show a dispersion larger than that in HCN/HNC. Moreover, we have found no correlation between D/H and 14 N/ 15 N in HNC. These findings indicate that: (1) the chemical evolution does not seem to play a role in the fractionation of nitrogen; (2) the fractionation of hydrogen and nitrogen in these objects are not related.

show abstract

Section: Observationsmentioning

confidence: 99%

Nitrogen and hydrogen fractionation in high-mass star-forming cores from observations of HCN and HNC

Colzi

Fontani

Caselli

et al. 2018

A&A

View full text Add to dashboard Cite

show abstract

“…We modelled the formation and the deuteration of complex organics at the surface of interstellar grains through radical recombinations and hydrogenation reactions by incorporating the surface chemical network of Garrod et al (2008). We only focused our study on a few prototype COMs; methyl formate (HCOOCH 3 ), methyl cyanide (CH 3 CN), di-methyl ether (CH 3 OCH 3 ), and formic acid (HCOOH) whose sub-millimetric spectra of their deuterated isotopologues have recently been measured in laboratories (Margulès et al 2010;Cazzoli et a. 2011;Richard et al 2013;Nguyen et al 2013;Coudert et al 2013), allowing recent and future detections towards low-mass protostars.…”

Section: Consequences On Complex Organics Deuterationmentioning

confidence: 99%

Multilayer Formation and Evaporation of Deuterated Ices in Prestellar and Protostellar Cores

Taquet

Charnley

Sipilä

2014

ApJ

133

213

View full text Add to dashboard Cite

Extremely large deuteration of several molecules has been observed towards prestellar cores and low-mass protostars for a decade. New observations performed towards low-mass protostars suggest that water presents a lower deuteration in the warm inner gas than in the cold external envelope. We coupled a gas-grain astrochemical model with a one-dimension model of collapsing core to properly follow the formation and the deuteration of interstellar ices as well as their subsequent evaporation in the low-mass protostellar envelopes with the aim of interpreting the spatial and temporal evolutions of their deuteration. The astrochemical model follows the formation and the evaporation of ices with a multilayer approach and also includes a state-of-the-art deuterated chemical network by taking the spin states of H 2 and light ions into account.Because of their slow formation, interstellar ices are chemically heterogeneous and show an increase of their deuterium fractionation towards the surface. The differentiation of the deuteration in ices induces an evolution of the deuteration within protostellar envelopes. The warm inner region is poorly deuterated because it includes the whole molecular content of ices while the deuteration predicted in the cold external envelope scales with the highly deuterated surface of ices. We are able to reproduce the observed evolution of water deuteration within protostellar envelopes but we are still unable to predict the super-high deuteration observed for formaldehyde and methanol. Finally, the extension of this study to the deuteration of complex organics (COMs), important for the prebiotic chemistry, shows a good agreement with the observations, suggesting that we can use the deuteration to retrace their mechanisms and their moments of formation.

show abstract

“…Noting that the c -inertial axis of the complex is perpendicular to the X–Z plane, and recalling that the TMA monomer is an oblate top, the parallel axis theorem gives where μ is the pseudodiatomic reduced mass of the complex and each I gg is the moment of inertia of the indicated monomer about its g -inertial axis. Using values of I cc HCOOH and I aa TMA obtained from published rotational constants, − a value of R cm = 3.24406 Å was obtained for the parent isotopologue…”

Section: Analysis Of Rotational Constantsmentioning

confidence: 99%

“…A similar calculation using the C7 substitution data on the TMA gave a distance of 1.8362(22) Å between C7 and the center of mass of the parent complex, with a corresponding value of θ TMA = 23.7°. Using these results for R cm , θ HCOOH , and θ TMA , and the known structures of the monomer units, − the zero-point vibrationally averaged hydrogen bond length for the complex is determined to be 1.702 Å, with a vibrationally averaged O–H···N angle of 177°. These results are both chemically reasonable and in good agreement with the theoretical results, which give equilibrium values of the hydrogen bond length and bond angle of 1.623 Å and 177.2°, respectively.…”

Section: Analysis Of Rotational Constantsmentioning

confidence: 99%

The Trimethylamine–Formic Acid Complex: Microwave Characterization of a Prototype for Potential Precursors to Atmospheric Aerosol

2016

View full text Add to dashboard Cite

The reactions of amines and carboxylic acids have recently received attention for their possible role in the formation of atmospheric aerosol. Here, we report a microwave study of the trimethylamine-formic acid hydrogen-bonded complex, a simple prototype in which to study amine-carboxylic acid interactions. Spectra of three isotopologues of the system have been observed using a tandem cavity and chirped-pulse Fourier transform microwave spectrometer. The complex has a plane of symmetry, with the acidic proton of the formic acid directed toward the lone pair of the nitrogen. The zero-point-averaged hydrogen bond length is 1.702 Å, and the O-H···N angle is 177°. (14)N nuclear quadrupole hyperfine structure has been used to assess the degree of proton transfer from the formic acid to the trimethylamine. Experimental results are supplemented with density functional theory calculations. M06-2X/6-311++G(3df,3pd) calculations indicate a binding energy of 16.8 kcal/mol with counterpoise correction (17.4 kcal/mol without counterpoise correction).

show abstract

Precise Laboratory Measurements of Trans-Dcooh and Trans-Hcood for Astrophysical Observations

Cited by 7 publications

References 44 publications

Nitrogen and hydrogen fractionation in high-mass star-forming cores from observations of HCN and HNC

Nitrogen and hydrogen fractionation in high-mass star-forming cores from observations of HCN and HNC

Multilayer Formation and Evaporation of Deuterated Ices in Prestellar and Protostellar Cores

The Trimethylamine–Formic Acid Complex: Microwave Characterization of a Prototype for Potential Precursors to Atmospheric Aerosol

Contact Info

Product

Resources

About