文摘
The gas-phase laser-induced fluorescence (LIF) spectrum of a 1-phenylpropargyl radical hasbeen identified in the region 20800-22000 cm-1 in a free jet. The radical was produced from dischargesof hydrocarbons including benzene. Disregarding C2, C3, and CH, this radical appears as the most stronglyfluorescing product in a visible wavelength two-dimensional fluorescence excitation-emission spectrumof a jet-cooled benzene discharge. The structure of the carrier was elucidated by measurement of a matchingresonant two-color two-photon ionization spectrum at m/z = 115 and density functional theory. Theassignment was proven conclusively by observation of the same excitation spectrum from a low-currentdischarge of 3-phenyl-1-propyne. The apparent great abundance of the 1-phenylpropargyl radical indischarges of benzene and, more importantly, 1-hexyne may further underpin the proposed importance ofthe propargyl radical in the formation of complex hydrocarbons in combustion and circumstellar environments.