Spectroscopic study of N[sub 2]O[sup +](A [sup 2]Σ[sup +]) by photofragment excitation spectrum.

Photofragment NO[sup +] excitation spectrum of N[sub 2]O[sup +] ions has been studied in the wavelength range of 278–328 nm, where the parent N[sub 2]O[sup +] ions were state-selectively prepared at the X [sup 2]Π[sub 1/2,3/2](000) levels by [3+1] multi-photon ionization of jet-cooled N[sub 2]O molecules at 360.55 nm. The spectrum was attributed completely to the A [sup 2]Σ[sup +]←X [sup 2]Π[sub 3/2,1/2](000) electronic transition of N[sub 2]O[sup +]. Totally 47 vibronic bands associated to 24 vibrational levels of the A [sup 2]Σ[sup +] state were identified in the present work, most of which were observed for the first time. The sufficient spectroscopic data made it possible to investigate the Fermi-resonance between the ν[sub 1] and ν[sub 2] vibrational modes at the A [sup 2]Σ[sup +] state. Based on the assignment, the spectral constants of the A [sup 2]Σ[sup +] state, such as vibrational frequencies, anharmonic constants, and Fermi interaction constant, were determined with relatively high reliability and precision. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]