1. Laboratory detection and astronomical search of N-ethynylmethanimine, H2CNCCH.
- Author
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Cabezas, C, Endo, Y, Rivilla, V M, Agúndez, M, Jiménez-Serra, I, Martín-Pintado, J, and Cernicharo, J
- Subjects
ELECTRIC discharges ,MICROWAVE spectroscopy ,MOLECULAR clouds ,CHEMICAL reactions ,INTERSTELLAR medium ,ACETONITRILE - Abstract
The presence in the interstellar medium of several imines suggests that other molecules of the same family could be present as well. The propargylimine molecule (HCCCHNH), which arises from CCH substitution on the C atom of methanimine (H
2 CNH), the simplest imine, has been recently detected in space. Therefore, the analogous CCH derivative substituted on the N atom, known as N-ethynylmethanimine (H2 CNCCH), is a good candidate to be observed as well. To allow for its astronomical detection we have investigated its laboratory rotational spectra. The species has been produced by an electric discharge of acetonitrile (CH3 CN) and acetylene (HCCH) in argon, and its rotational spectrum between 9 and 40 GHz has been characterized using a Balle–Flygare narrow band-type Fourier-transform microwave spectrometer. The spectral analysis allowed us to derive accurate spectroscopic parameters to obtain reliable frequency predictions for astronomical searches in different sources. We searched for H2 CNCCH in several molecular clouds, G+0.693−0.027, L483, and TMC-1, but did not detect it. The upper limits to its abundance derived are consistent with a preference of the CCH substitution of H2 CNH on the C atom rather than on the N atom, in line with quantum chemical calculations on the reaction between CCH and H2 CNH. [ABSTRACT FROM AUTHOR]- Published
- 2024
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