INFRARED AND MICROWAVE MOLECULAR-BEAM STUDIES OF N2O5

Rotational spectra of the P-r(0) and R-r(0) b-type subbands of N2O5 fo r both internal rotor states were recorded using a pulsed-nozzle Fouri er-transform microwave spectrometer. The present measurements extend o ur previous results on N2O5 which were confined to the R-r(0), R-r(1), (r)Q(1), and P-r(1), b-type subbands due to limitations in the freque ncy coverage of the instrument. The present measurements provide new e nergy-level differences which give a nearly complete experimental pict ure of the K = 0, 1, and 2 energy levels. The measurements also suppor t our previous picture of N2O5 as a C-2 symmetry molecule with facile geared internal rotation of the two equivalent NO2 groups. Infrared sp ectra of the 1246 cm(-1) nu(12), N-O stretching fundamental band of N2 O5 were also recorded using a lead-salt diode-laser spectrometer and a slit-jet nozzle molecular-beam apparatus. The spectra reveal a comple x resolved rotational structure which is at present unanalyzed. (C) 19 97 Academic Press.