The infrared spectrum of C3O2 : The interaction between [nu]7 and the [nu]2 and [nu]4 vibrations

Abstract

The , , and hot bands of the [nu]4 fundamental of C3O2 in the 1580 cm-1 region were analyzed from tunable diode laser spectra and the ground state to band at 1644 cm-1 from Fourier transform spectra (FTS). The molecular constants for all of the v4 1 4 fundamental were in agreement with the predictions of the model of Weber and Ford. FTS spectra at 0.05 cm-1 resolution were obtained of the sum and difference bands of [nu]2 with [nu]7 in the 750-900 cm-1 region. Sharp Q branches occur for each [nu]7 state in the sum bands, but only a number of R-branch bandheads and no recognizable Q branches in the difference bands. Assignments of the sum band Q branches through v7 = 6 were made and molecular constants were determined for the transition at 819.7 cm-1. The [nu]7 potential function in the v2 = 1 state was found to have a 1.2 cm-1 barrier with a minimum at [alpha] = 4.9[deg], where 2[alpha] is the angular deviation from linearity. The Q-branch positions predicted from the calculated energy levels fit those observed within several cm-1.