Rotational analysis ofA 1Π-X 1Σ+ bands of As14N and As15N: perturbation studies in theA 1Π state

The ultraviolet bands ofA ¹Π-X ¹Σ⁺ system of As¹⁴N and its isotopic species As¹⁵N were excited in a quartz tube containing specpure nitrogen and traces of AsCl₃ vapour, using a microwave discharge (2450 MHz). Bands of As¹⁵N were obtained using¹⁵N₂ enriched to 95.5%. Rotational structure of several bands of As¹⁴N and As¹⁵N photographed under high dispersion (0.14 Å/mm) was reanalysed. Detailed studies of the observed perturbations in the levels ofν′ = 0 to 4 led to the identification of two³Σ^? and aC ¹Σ^? states. Molecular parametersT _e, ω_e, ω_ex_e, B_eandα _ewere determined for all the electronic states studied. Vibrational assignments of the perturbing levels were made using the isotope shift studies.