A new triplet band system of C3: The <i>b</i> 3Π<i>g</i>–<i>a</i> 3Π<i>u</i> transition

Abstract

A triplet band system of C3 has been observed for the first time in absorption with a distributed-feedback (DFB) diode laser spectrometer and in emission with a Fourier transform spectrometer at around 6500 cm−1. The band has been assigned to the b̃ 3Πg–ã 3Πu system, and the spectroscopic constants in both the upper and lower states have been determined. It is demonstrated that near-infrared DFB lasers are promising radiation sources for spectroscopy of unstable molecules.