Knowledge Bank

Rotational transitions of the linear molecules FCN and HCCCN have been detected in excited vibrational states several thousand $cm-1$ above the ground state in DC glow discharges through various gas mixtures. A large number of lines have been found for cyanoacetylene in $N2/CH4$ discharges, corresponding to both stretching and bending modes. Satellites corresponding to all normal modes of FCN have been observed in $N2/CF4$ discharges. Efforts to obtain precise equilibrium structures and anharmonic force fields of these molecules are in progress.