Microwave spectra of molecules of astrophysical interest XV. Propyne

The microwave spectrum of propyne is critically reviewed for information applicable to radio‐astronomy. Molecular data such as the derived rotational constants, centrifugal distortion parameters, hyperfine coupling constants, electric dipole moment, and molecular structure are tabulated. The observed rotational transitions are presented for the astronomically interesting isotopic forms and the lowest lying vibrational state of propyne. Calculated rotational transitions are presented for the ground vibrational state of ¹²CH₃ ¹²C≡ ¹²CH, ¹³CH₃ ¹²C≡ ¹²CH, ¹²CH₃¹³C≡ ¹²CH and ¹²CH₃ ¹²C≡ ¹³CH, and for the vibrationally excited state ν₁₀ of ¹²CH₃ ¹²C≡ ¹²CH.