Laser induced fluorescence spectroscopy of the HC6S radical

New vibronic bands were observed in the 17 000–17 600 cm−1 region by laser induced fluorescence (LIF) spectroscopy in the discharged products of a mixture of C2H2 and CS2 in a supersonic jet. The effective rotational constants and the position of the vibronic band origin have been determined to be B″eff=0.01910(2) cm−1,B′eff=0.01891(2) cm−1, and T0=16961.5161(5) cm−1, respectively. The spectral carrier of the bands has been confirmed to be the HC6S radical from the chemical behavior of the products and the determined rotational constant.