Interaction of the C' 3Πu and C 3Πu states in 14N 2, 14N 15N, and 15N 2

A complex band was photographed at high resolution in absorption in flash discharges through ¹⁴N ₂, ¹⁴N ¹⁵N, and ¹⁵N ₂. Analysis of the band has demonstrated that the lower state is the B ³Π_g, v = 5, state and that the upper state is a ³Π _u state which had previously been observed in low-resolution emission spectra by Tanaka and Jursa. The analysis of the rotational structure and of the spin splitting confirms that this state is a mixture of the C' ³Π_u, v = 1, and C ³Π_u, v = 5, states, as had been suggested by Carroll and Mulliken. The observed and deperturbed molecular constants of these states are presented for all three isotopes.