Low temperature synthesis of three cyanocyclopentadiene isomers and their role in interstellar cyano PAH formation.
5 affiliations
- 1Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI, USA.
- 2Department of Chemistry, National Dong Hwa University, Hualien, Taiwan, ROC.
- 3Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI, USA. [email protected].
- 4Department of Chemistry, National Dong Hwa University, Hualien, Taiwan, ROC. [email protected].
- 5Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI, USA. [email protected].
Abstract
The recent detection of polycyclic aromatic hydrocarbons and their cyano derivatives in the Taurus Molecular Cloud challenges existing models of their formation and survival under such harsh conditions. Cyanocyclopentadienes have emerged as fundamental molecular building blocks for cyano-substituted aromatics, yet their formation in the interstellar medium remains unknown. Here, we report the gas-phase formation of distinct cyanocyclopentadiene isomers through the bimolecular reaction of 1,3-cyclopentadiene with the cyano radical explored through molecular beam studies and electronic structure calculations. Three cyanocyclopentadiene isomers are identified: the astronomically observed 1-cyanocyclopentadiene and 2-cyanocyclopentadiene species and the elusive 5-cyanocyclopentadiene. Remarkably, the reaction predominantly forms the unobserved 5-cyanocyclopentadiene isomer accounting for two-thirds of the products, according to dynamics-guided statistical calculations. These results identify 5-cyanocyclopentadiene as a key precursor to cyano-substituted aromatics, reveal a gap in current astronomical observations, and motivate targeted searches for this elusive molecule in cold molecular clouds.
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BibTeX
@article{gonzalez2026temperature,
title = {{Low temperature synthesis of three cyanocyclopentadiene isomers and their role in interstellar cyano PAH formation.}},
author = {Daniel González and Nils W Melbourne and Siti Fatimah and Iakov A Medvedkov and Surajit Metya and Shane J Goettl and Tianlcen Bian and Zuxiao Zhang and Rui Sun and Agnes H H Chang and Ralf I Kaiser},
journal = {Nature communications},
year = {2026},
month = sep,
doi = {10.1038/s41467-026-78116-5},
url = {https://europepmc.org/article/MED/42957691},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Low temperature synthesis of three cyanocyclopentadiene isomers and their role in interstellar cyano PAH formation.
AU - Daniel González
AU - Nils W Melbourne
AU - Siti Fatimah
AU - Iakov A Medvedkov
AU - Surajit Metya
AU - Shane J Goettl
AU - Tianlcen Bian
AU - Zuxiao Zhang
AU - Rui Sun
AU - Agnes H H Chang
AU - Ralf I Kaiser
PY - 2026
DA - 2026/09/28
JO - Nature communications
DO - 10.1038/s41467-026-78116-5
UR - https://europepmc.org/article/MED/42957691
AB - The recent detection of polycyclic aromatic hydrocarbons and their cyano derivatives in the Taurus Molecular Cloud challenges existing models of their formation and survival under such harsh conditions. Cyanocyclopentadienes have emerged as fundamental molecular building blocks for cyano-substituted aromatics, yet their formation in the interstellar medium remains unknown. Here, we report the gas-phase formation of distinct cyanocyclopentadiene isomers through the bimolecular reaction of 1,3-cyclopentadiene with the cyano radical explored through molecular beam studies and electronic structure calculations. Three cyanocyclopentadiene isomers are identified: the astronomically observed 1-cyanocyclopentadiene and 2-cyanocyclopentadiene species and the elusive 5-cyanocyclopentadiene. Remarkably, the reaction predominantly forms the unobserved 5-cyanocyclopentadiene isomer accounting for two-thirds of the products, according to dynamics-guided statistical calculations. These results identify 5-cyanocyclopentadiene as a key precursor to cyano-substituted aromatics, reveal a gap in current astronomical observations, and motivate targeted searches for this elusive molecule in cold molecular clouds.
SN - 2041-1723
ER -