High-resolution FTIR spectroscopy of the ν7 and ν8 bands of 1-phosphapropyne

► 1-Phosphapropyne has been prepared. ► Far infrared spectra have been recorded with a synchrotron source. ► Ro-vibrational transitions of ν8 (308 cm−1), ν7 (1006 cm−1) and hot bands assigned. ► B3LYP/cc-pVTZ predicted constants match well with experiment.