Probing the Chemical Complexity of Amines in the ISM: Detection of Vinylamine (C₂H₃NH₂) and Tentative Detection of Ethylamine (C₂H₅NH₂)

Abstract

Amines, particularly primary amines (R-NH2), are closely related to the primordial synthesis of amino acids since they share the same structural backbone. However, only a limited number of amines has been identified in the interstellar medium, which prevents us from studying their chemistry as well as their relation to prebiotic species that could lead to the emergence of life. In this Letter, we report the first interstellar detection of vinylamine (C2H3NH2) and tentative detection of ethylamine (C2H5NH2) toward the Galactic center cloud G+0.693-0.027. The derived abundance with respect to H2 is (3.3 ± 0.4) × 10−10 and (1.9 ± 0.5) × 10−10, respectively. The inferred abundance ratios of C2H3NH2 and C2H5NH2 with respect to methylamine (CH3NH2) are ∼0.02 and ∼0.008, respectively. The derived abundance of C2H3NH2, C2H5NH2, and several other NH2-bearing species are compared to those obtained toward high-mass and low-mass star-forming regions. Based on recent chemical and laboratory studies, possible chemical routes for the interstellar synthesis of C2H3NH2 and C2H5NH2 are discussed.

The SKA as a Prebiotic Molecule Detector

“…Giant Molecular Clouds (GMCs) located in the Galactic Center such as the molecular cloud G+0.693-0.027 (hereafter G+0.693) have proven to be not only efficient chemical factories for the formation of complex organics (Requena-Torres et al, 2006;Requena-Torres et al, 2008;Zeng et al, 2018), but also excellent targets for the discovery of new prebiotic species (see e.g., Jiménez-Serra et al, 2020;Rivilla et al, 2020;Rivilla et al, 2021;Zeng et al, 2021). These clouds show low H 2 gas densities of ~10 4 cm −3 and their gas and dust temperatures are decoupled (while T dust ≤ 20K, T gas ~70-150 K; see Rodríguez-Fernández et al, 2000;Zeng et al, 2018).…”

“…This sub-set of COMs are typically called prebiotic. Some examples of prebiotic COMs include urea and hydroxylamine (Belloche et al, 2019;Jiménez-Serra et al, 2020;Rivilla et al, 2020) since they are possible precursors of ribonucleotides (see e.g., Becker et al, 2019;Menor Salvan et al, 2020); ethanolamine and n-propanol because they could have triggered the formation of phospholipids (Jiménez-Serra et al, 2022;Rivilla et al, 2021); or amino acetonitrile, vynil amine and ethyl amine since they are considered precursors of amino acids (Belloche et al, 2008;Zeng et al, 2021).…”

Deuterium fractionation as a multi-phase component tracer in the Galactic Centre

“…The data presented in this work was taken from the high-sensitivity spectral survey towards the G+0.693 molecular cloud (e.g. Rodríguez-Almeida et al 2021a,b;Rivilla et al 2021;Zeng et al 2021) carried out with the IRAM 30m (Granada, Spain) and APEX (Chajnantor, Chile) radiotelescopes . The observations, centered at α J2000 = 17 h 47 m 22 s and δ J2000 = -28 • 21 27 , were made in position-switching mode, with the off position located at (-885 ,+290 ) with respect to G+0.693.…”

“…The blue line indicates the total modelled line emission, including also the contribution of all molecular species previously identified in the survey (e.g. Rodríguez-Almeida et al 2021a,b;Rivilla et al 2021;Zeng et al 2021).…”

“…The orange line is the best LTE fit to the pre-stellar component, the green line is the best LTE fit to the broad gas component, and the red line is the sum of the components. The blue line indicates the total modelled line emission, including also the contribution of all molecular species previously identified in the survey (e.g.Rodríguez-Almeida et al 2021a,b;Rivilla et al 2021;Zeng et al 2021).…”