Laboratory Detection and Submillimeter Spectrum of N[CLC]a[/CLC]CCH ([FORMULA][F][A][AC]X[/AC][AC][d5][/AC][/A][/F][/FORMULA] [CLC][TSUP]1[/TSUP]Σ[/CLC])

Abstract

Sodium monoacetylide has been observed in the laboratory for the first time using millimeter/submillimeter direct absorption techniques. The species was produced by the reaction of sodium vapor and acetylene under DC discharge conditions. Nineteen rotational transitions of NaCCH in its X1Σ ground state and 14 lines of the deuterium isotopomer NaCCD were recorded in the range 270-510 GHz. From these data, highly accurate rotational constants were determined. The detection of NaCN and NaCl in the envelope of the evolved carbon star IRC +10216 suggests that other sodium-bearing species may be present in this object.