High-Resolution Study of the Triplet Acetylene

Abstract

A triplet state of acetylene was generated by pulsed mercury photo-sensitized technique and was detected by using near infrared diode laser kinetic spectroscopy. Hundreds of lines were observed in Doppler limited resolution and were assigned to the c-type electronic transition of a triplet asymmetric rotor. The intensity alternation due to two equivalent protons appeared in the asymmetry (K-)doubling clearly showed that the structure of the triplet acetylene is cis-bend. The band origin and rotational constants agrees well to low resolution $spectra^{1})$ and theoretical results of the acetylene in the triplet states, respectively. A same results were also obtained in the deuterized species.