This work is in memory of Dr. Jon Hougen deceased on January 28th 2019 who dedicated his life to spectroscopy and worked on the present project very actively untill the end of December 2018. We will show the latest results obtained with Jon on the fit of more than 15000 rotational-torsional-wagging transitions in the MW and FIR of v_t = 0,1 of CH₃NH₂. We used the recently written hybrid program to fit rotational levels in molecules with one CH₃ internal-rotation large-amplitude motion, one NH₂ inversion large-amplitude motion, and symmetry described by the G₁₂ PI groupJ. T. Hougen and I. Kleiner, J. Phys. Chem. A, 2015, 119, 10664 We will first present an overview of our present best least-squares fit. The data set contains slightly less than 2500 MW and 12754 FIR transitions, which are fit to a weighted standard deviation of 1.13 using 74 parameters. Most of the FIR transitions are taken from recent measurements of the v_t = 1-0 band centered near 265 cm⁻¹I. Gulaczyk, M. Kreglewski, V.-M. Horneman, J. Mol. Spectrosc. 2017,342, 25 but a number of lines were re-assigned or remeasured. The ground torsional state (taken mostly from Motyienko et alR.A. Motiyenko, V.V. Ilyushin, B.J. Drouin, S. Yu, L. Margulès, Astron.and Astrophys. 2014, 563, A1 fit within measurement uncertainty but 75 older MW measurements in the v_t = 1 showed large observed-calculated residuals and were presently discarded from the fit. We believe that our fit, as well as the predictive abilities of the program, are now sufficiently good that we can begin a new measurement campaigns of v_t = 1 MW data and v_t = 2, 3 IR data. This new project will be discussed in the talkPart of this work has been funded by the Programme National de Physique Chimie du Milieu Interstellaire (PCMI)

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J. T. Hougen and I. Kleiner, J. Phys. Chem. A, 2015, 119, 10664. I. Gulaczyk, M. Kreglewski, V.-M. Horneman, J. Mol. Spectrosc. 2017,342, 25, R.A. Motiyenko, V.V. Ilyushin, B.J. Drouin, S. Yu, L. Margulès, Astron.and Astrophys. 2014, 563, A1) Part of this work has been funded by the Programme National de Physique Chimie du Milieu Interstellaire (PCMI).

The reactions of molecules in interstellar space occur over a wide range of temperatures, down to 10 K or colder. The study of gas-phase chemical reactions at these temperatures has been difficult until the development and implementation of the CRESU (French acronym for Reaction Kinetics in Uniform Supersonic Flow) technique in Rennes. Reaction kinetics at temperatures as low as 6 K has been monitored, but product branching ratios have not yet been measured at such low temperatures. The recent development of the CPUF (Chirped Pulse in Uniform supersonic Flow) technique has shown that chirped pulse spectroscopy can be combined with uniform supersonic flows, so that the branching ratios of chemical reactions can be examined. This has been extended to the continuous CRESU flows at Rennes, taking advantage of the deep averaging capabilities of chirped pulse Fourier transform spectrometers complementing the continuous flows. An E-band chirped pulse Fourier transform spectrometer has been incorporated into a current CRESU instrument to detect reaction products. The effects that the uniform flow has on molecular spectra have been characterized in this frequency range. Reactions of ethylene and cyanide radicals have been monitored using pulsed laser photolysis for product detection. The branching ratios of reactions will be discussed, as well as future directions of the instrument.

Electrical discharge sources have been used extensively for the generation of molecular ions, radicals, and long chain unsaturated hydrocarbons, which have consequently been discovered to be present in the interstellar medium (ISM) [1]. We have used a discharge source to produce a number of medium-sized, astronomically relevant, neutral organic molecules from multi-component mixtures. The discharge products are characterised with our segmented chirped-pulse Fourier transform millimeter-wave spectrometer, which has been previously applied in our room-temperature studies of cyanides and alcohols [2]. We will concentrate here on the discharge products of mixtures of molecules already detected in the ISM, such as aldehydes in mixture with the nitrogen-containing molecules acetonitrile and ammonia. Any newly-observed species in our spectra can be assigned with rest frequencies and rotational parameters already suitable for interstellar searches with millimeter-wave radio telescopes, such as the Atacama Large Millimeter/submillimeter Array. Results from our experiments will allow us to better consider reaction pathways towards complex organic molecules in extra-terrestrial environments. References: [1] M. C. McCarthy et al., Astrophys. J. Suppl. Ser. 129 (2000), 611-623. [2] B.E. Arenas et al., Phys. Chem. Chem. Phys. 19 (2017), 1751-1756.

Aminomethanol is predicted to be present in the interstellar medium (ISM) as a reaction product of radical chemistry in ice mantles on interstellar grains. Aminomethanol is of particular interest as it is a precursor molecule in the reaction predicted to form glycine, the simplest amino acid, in the ISM. Under terrestrial conditions, aminomethanol is unstable and thus must be produced in a supersonic expansion for spectral characterization. Previous work in our lab has used the photolysis of ozone to form electronically excited oxygen atoms, O(¹D), which insert into a C-H bond in methylamine to form aminomethanol. Analysis of this spectrum, however, has proved difficult due to a significant number of transitions present in the spectrum as a result of the reaction of ozone with methylamine. We have performed a study collecting the spectra of methylamine and ozone mixtures under dark conditions to determine the reaction products and assign the spectra in order to clarify the spectral measurements under photolysis conditions. We will report on this analysis, including the assignment of previously unassigned vibrationally excited states of methylamine up to 1 THz.

Insertion of O(¹D) into stable precursors has proved an efficient way of producing molecules that are reactive or otherwise unstable under terrestrial conditions. O(¹D) reaction with hydrocarbons occurs preferentially via a barrierless insertion into C-H bonds. Previously in our lab, O(¹D) has been produced via photodissociation of ozone at 248 nm. We have reported successful production of methanol and vinyl alcohol from insertion into methane and ethylene respectivelyB. M.Hays, N. Wehres, B. Alligood DePrince, A. A.M. Roy, J. C. Laas, S. L. Widicus Weaver, Chem.Phys. Lett., 630, 18 (2015) where the excess rotational and vibrational energy was quenched using a supersonic expansion, thereby stabilizing the direct insertion product. Using this technique described by Hays et. al., we aim to produce the important glycine precursor, aminomethanol, via insertion into methylamine. Preliminary results have been obtained using O₃ as the precursor for O(¹D) production, but the side reactions between O₃ and methylamine produce such a wide variety of products that spectral assignment for aminomethanol is hampered. We propose to photodissociate N₂O using 193 nm light as a source of O(¹D) production in order to eliminate the multitude of side reactions observed with ozone. Here we will present the efforts made towards producing aminomethanol and collecting its rotational spectrum in the millimeter/sub-millimeter region.

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B. M.Hays, N. Wehres, B. Alligood DePrince, A. A.M. Roy, J. C. Laas, S. L. Widicus Weaver, Chem.Phys. Lett., 630, 18 (2015),

r0pt Figure Formamide [H₂NC(O)H], the smallest molecule containing the biologically important peptide bond, was detected in the interstellar medium (ISM) almost 50 years ago. Recent observations have shown that a strong correlation between its abundance and that of isocyanic acid [HNCO] exists in pre- and protostellar environments. It was proposed that this correlation is due to effective synthesis of formamide from HNCO by consecutive H-atom addition reactions.Lòpez-Sepulcre, Montly Not. Roy. Astr. Soc. 449, 2438–2458 (2015).owever, Nobel et al. showed that bombardment of HNCO ice with H atoms led no formation of formamide.Nobel, J. A., et al., Astron. Astrophys. 576, A91 (2015).o far, no laboratory experiment or theoretical calculations can explain the linkage between these two species.
We utilized the advantages of the solid para-H₂ quantum host to investigate the H-atom reactions linking HNCO and formamide. Reactions of H₂NC(O)H with H atoms lead to H₂NCO, and subsequently HNCO. Further hydrogenation reactions convert some HNCO back to H₂NCO and H₂NC(O)H; the reaction with D₂NC(O)H clearly showed that these reactions took place. The correlation between the abundance of HNCO and H₂NC(O)H can hence be understood by a dual-cycle mechanism shown in the figure, which connects the two species by a quasi-equilibrium. This mechanism and its generalized form for other molecular pairs can also play an important role in the formation of interstellar H₂ from H atoms.

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Lòpez-Sepulcre, Montly Not. Roy. Astr. Soc. 449, 2438–2458 (2015).H Nobel, J. A., et al., Astron. Astrophys. 576, A91 (2015).S

Over 200 molecules have been detected in the interstellar medium (ISM) with close to one third considered to be complex organic molecules (COMs), molecules containing six or more atoms. Gas-phase reaction networks of ion-molecule and neutral-neutral reactions have aided in the understanding of the evolution of the interstellar medium (ISM). However, these models fail to explain the synthesis of ubiquitous COMs with predicted abundances several orders of magnitude lower compared to observations in the ISM, such as in Sagittarius B2. Over the last decades astrophysical laboratory simulation experiments have shown that some of these COMs are formed via interaction of ionizing radiation within simple ices deposited on interstellar dust particles at 10 K (, , CO, , , \ceNH3). After processing the ice temperature programmed desorption was utilized to sublime the ice along with its newly formed products for analysis with single photon vacuum ultraviolet ionization coupled with a reflectron time-of-flight mass spectrometer (PI-ReTOF-MS). The use of PI-ReTOF-MS allows for the selective ionization and identification of structural isomers of COMs. Here, we report that the key COMs propynal (HCCCHO) and cyclopropenone (), which have both been detected in the ISM, can be synthesized within interstellar ices containing carbon monoxide (CO) and acetylene () at temperatures as low as 5 K. This is accomplished via non-equilibrium chemistry induced by the energetic electrons simulating those produced by galactic cosmic rays penetrating interstellar ices. Furthermore, cyclic COMs may act as tracers for non-equilibrium chemical processes at 10 K involving electronically excited reactants such as acetylene in excited triplet state(s). The incorporation of solid state data from these experiments, such as yield, branching ratio, and chemical and temperature conditions, into astrochemical models accounting for non-equilibrium has been shown to greatly improve predicted abundances.

Only two dinitriles, the protonated cyanogen NCCNH⁺ and one isocyanonitrile, NCNC have been detected in the interstellar medium (ISM) among about 200 other compounds, despite nitriles constitute almost 20% of the molecules observed in the interstellar medium. The lack of detections of dinitriles may be explained by the lack of accurate spectroscopic data on their rotational spectra since most of them do not present permanent dipole moment. Succinonitrile, NCCH₂CH₂CN is one of the simplest dinitriles and it could be a candidate molecule to be observed in the ISM. The rotational spectrum for succinonitrile has been previously observed in the 2-78 GHz frequency region by Jahn et al.,M. K. Jahn, J.-U. Grabow, P. D. Godfrey and D. McNaughton, Phys.Chem.Chem.Phys., 2014, 16, 2100.ut these measurements were limited to the ground state. In this talk we report the study of succinonitrile and its low lying excited vibrational states using a newly built broadband Fourier transform millimeter wave spectrometer J. Cernicharo  et al., A&A, 2019.quipped with Q-band (31.5-50 GHz) and W-band (72-116 GHz) receivers, similar to those used in the radio-telescopes. The spectrometer is well suited for high resolution emission spectroscopy of molecules of astrophysical importance.

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M. K. Jahn, J.-U. Grabow, P. D. Godfrey and D. McNaughton, Phys.Chem.Chem.Phys., 2014, 16, 2100.b J. Cernicharo  et al., A&A, 2019.e