Fourier transform infrared observation of the ν2 stretching mode of the HCCCO radical in solid Ar

Abstract
The identification of a fundamental vibration of the HCCCO radical has been made in a Fourier transform infrared (FTIR) study involving extensive isotopic measurements. An absorption at 2308.6 cm−1 has been assigned to the ν2, antisymmetric CCCO stretching mode of HCCCO which was produced by trapping in Ar the products of the vacuum ultraviolet (VUV) photolysis of a mixture of acetylene and carbon monoxide. The assignment is confirmed by measurements for a variety of D‐, 18O‐, and 13C‐substituted isotopomers.