Laboratory and astronomical identification of cyclopropenylidene, C/sub 3/H/sub 2/

Journal Article · Sun Dec 01 00:00:00 EST 1985 · Astrophys. J., Lett. Ed.; (United States)

DOI:https://doi.org/10.1086/184581· OSTI ID:6292585

Thaddeus, P; Vrtilek, J M; Gottlieb, C A

Twenty-seven rotational lines of C/sub 3/H/sub 2/ have been identified in the laboratory or in astronomical sources, and the rotational and centrifugal distortion constants of this previously unobserved carbene ring determined to high accuracy. The assigned astronomical transitions include the strong, ubiquitous interstellar lines at 85338 MHz and 18343 MHz, which are the lowest lying transitions of ortho C/sub 3/H/sub 2/:2/sub 12/ ..-->.. 1/sub 01/ and 1/sub 10/ ..-->.. 1/sub 01/, respectively. Interstellar C/sub 3/H/sub 2/ can be rapidly formed by dissociative recombination of the very stable ion C/sub 3/H/sup +//sub 3/, which in turn can be produced from acetylene in only two steps. In standard molecular sources such as Ori A and Sgr B2, C/sub 3/H/sub 2/ is only moderately abundant, but in diffuse molecular clouds it may be one of the most abundant molecules. There is some radio spectroscopic evidence for two related molecules in Sgr B2 or TMC-1: ethynylmethylene HCCCH, a hypothetical carbon chain isomer, and cyclopropene, C/sub 3/H/sub 4/, a known, stable three-membered ring.

• Research Organization: Goddard Institute for Space Studies; and Columbia University
• OSTI ID: 6292585
• Journal Information: Astrophys. J., Lett. Ed.; (United States), Vol. 299:1
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
HYDROCARBONS
COSMOCHEMISTRY
INTERSTELLAR SPACE
ENERGY LEVELS
IONS
MOLECULES
RADIOWAVE RADIATION
RECOMBINATION
ROTATIONAL STATES
CHARGED PARTICLES
CHEMISTRY
ELECTROMAGNETIC RADIATION
EXCITED STATES
ORGANIC COMPOUNDS
RADIATIONS
SPACE
640105* - Astrophysics & Cosmology- Galaxies