title: Carbynes in meteorites: detection, low-temperature origin, and implications for interstellar molecules.
abstract: Carbon from the Allende meteorite is not graphite but carbyne (triply bonded elemental carbon), inasmuch as on heating to 250 degrees to 330 degrees C it releases mainly triply bonded fragments: -(C identical withC)(n),- with n = 1 to 5, and -(C identical withC)(n)-CN, with n = 1 to 3. Although carbynes have been known to form only by condensation of carbon vapor above 2600 K or by explosive shock of > 600 kilobars, it is found that they also form metastably by the reaction 2CO --> CO(2) + C (solid) at 300 degrees to 400 degrees C in the presence of a chromite catalyst. Such low-temperature formation by surface catalysis may be the dominant source of carbynes on the earth and in meteorites, and a major source of interstellar carbynes and cyanopolyacetylenes.
authors.forename: R
authors.initials: R
authors.lastname: Hayatsu
authors.forename: R G
authors.initials: RG
authors.lastname: Scott
authors.forename: M H
authors.initials: MH
authors.lastname: Studier
authors.forename: R S
authors.initials: RS
authors.lastname: Lewis
authors.forename: E
authors.initials: E
authors.lastname: Anders