Laboratory rotational spectroscopy and interstellar search for the protein precursor 4-oxobutanenitrile (HCOCH2CH2CN)

Understanding the presence and distribution of pre-biotic precursorsin the interstellar medium (ISM)is key to tracing the chemical origins of life. Among them, 4-oxobutanenitrile (HCOCH2CH2CN) has been identified in laboratory simulations as a plausible intermediate in the formation of glutamic acid...

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Detalles Bibliográficos
Autores: Rivilla, Victor M., Alonso, Elena Rita, Song, W., Insausti Beiro, Aran, Maris, Assimo, Basterretxea, Francisco J., Melandri, Sonia, Jimenez-Serra, Izaskun, Cocinero, Emilio J.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2026
País:España
Institución:Instituto Nacional de Técnica Aeroespacial (INTA)
Repositorio:DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacial
OAI Identifier:oai:dnet:digital.inta::1ce01292062a8a8b42d973125d94f799
Acceso en línea:https://academic.oup.com/mnras/article/546/1/staf2224/8384188
https://hdl.handle.net/20.500.12666/1763
Access Level:acceso abierto
Palabra clave:Molecular data
Astrobiology
Astrochemistry
ISM: abundances
ISM: molecules
Methods: laboratory: molecular
Descripción
Sumario:Understanding the presence and distribution of pre-biotic precursorsin the interstellar medium (ISM)is key to tracing the chemical origins of life. Among them, 4-oxobutanenitrile (HCOCH2CH2CN) has been identified in laboratory simulations as a plausible intermediate in the formation of glutamic acid, a proteinogenic amino acid. Here, we report its gas-phase rotational spectrum, measured using two complementary techniques: chirped-pulse Fourier transform microwave (CP-FTMW) spectroscopy (2– 18 GHz) and free-jet millimetre-wave (FJ−AMMW) absorption spectroscopy (59.6–80 GHz). Quantum chemical calculations revealed nine low-energy conformers, of which the TC conformer was assigned based on the measured spectra. The resulting spectroscopic parameters were used to search for the molecule in the ultradeep spectral survey of the G+0.693-0.027 molecular cloud, located in the Galactic Center. No signal attributable to 4−oxobutanenitrile was detected. A stringent upper limit to its column density was derived (N < 4 ×1012 cm−2), corresponding to a molecular abundance of <2.9 ×10−11 relative to H2. This upper limit lies well below the observed abundances of simpler structurally related species containing −HCO and −CN groups, underscoring the challenge of detecting increasingly complex pre-biotic molecules in the ISM and the need for future, more sensitive astronomical facilities.