Fourier transform infrared spectroscopy of the ν3 band of cyclopropenylidene, C3H2

Abstract
The gas‐phase absorptionspectrum of the ν3 band of cyclopropenylidene (cyclic C3H2 ) has been observed with a high‐resolution Fourier transforminfrared spectrometer. The ring molecule was generated by a microwavedischarge in an allene and Ar mixture. The spectrum observed between 1250 and 1305 cm−1 was analyzed by using Watson’s A‐reduced Hamiltonian to determine the band origin (ν0=1277.3711±0.0001 cm−1 ), rotational constants, and centrifugal distortion constants in the ν3 state.