Band Spectrum of the Bn Molecule

In a discharge through helium with traces of boron trichloride and nitrogen two new band systems (a triplet system and a singlet system) were found which are shown to be due to the BN molecule. The first system represents a 3 II– 3 II transition similar to the Swan bands of the C 2 molecule with which BN is isoelectronic. A vibrational and rotational analysis of this system is carried out and yields the formula for the heads:[Formula: see text]and the B and α values and internuclear distances: [Formula: see text], [Formula: see text], α′ = 0.010, α″ = 0.025, [Formula: see text], [Formula: see text]. An analysis of the singlet system has not as yet been possible.