Gas phase formation of c-SiC 3 molecules in the circumstellar envelope of carbon stars

• DOI: 10.1073/pnas.1810370116
• Publication Date: 2019-07-02T00:24:32Z
• Authors: Tao Yang; Luke Bertels; Beni B. Dangi; Xiaohu Li; Martin Head-Gordon; Ralf I. Kaiser
• Keywords: Organosilicon; Carbon fibers; Carbon star; Circumstellar envelope

Significance Since the detection of methylidyne (CH) in deep space over 80 y ago, about 200 molecules and molecular ions from hydrogen to fullerenes have been observed interstellar circumstellar environments, but synthesis organosilicon has remained largely elusive. Exploiting silicon tricarbide (c-SiC 3 ) as a benchmark, we provide evidence laboratory experiments, electronic structure calculations, astrochemical modeling that species can be synthesized via distinct chemistries inner outer envelope carbon stars like IRC+10216 bimolecular reactions followed by photochemical dehydrogenation bare molecules. These mechanisms are fundamental significance facilitate an understanding how coupled synthesize universe.