{"paper":{"title":"Laboratory spectroscopy, theoretical characterization, and astronomical search for syn-propenethial (CH2CHCHS)","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Carlos Cabezas, Germ\\'an Molpeceres, Gisela Esplugues, Jos\\'e Cernicharo, Lucie Kolesnikov\\'a, Marcelino Ag\\'undez, Mar\\'ia Mallo, Yasuki Endo","submitted_at":"2026-07-27T16:52:52Z","abstract_excerpt":"We report the laboratory characterization of the higher-energy isomer of propenethial, syn-CH2CHCHS. While the lower-energy isomer, anti-CH2CHCHS, was detected in the interstellar medium during the QUIJOTE line survey of TMC-1, we report the non-detection of the syn isomer in the same source, deriving an upper limit to its column density of 1.5 $\\times$ 10$^{10}$ cm$^{-2}$. A subsequent theoretical investigation into the origin of this non-detection reveals that the most plausible formation pathway for CH2CHCHS is highly isomer-specific, producing nearly 95\\% of the anti isomer. This predicted"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.24656","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2607.24656/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}