The ν6 band system of c3o2 near 540 cm-11

Abstract The infrared spectrum of the ν 6 band system of carbon suboxide, C 3 O 2 , has been recorded between 500 and 600 cm −1 at a resolution of 0.002 cm −1 . Altogether 23 bands have been assigned. They correspond to transitions ν 6 + n ν 7 ← n ν 7 , n ≤ 9, where ν 6 is the asymmetric CCO bending mode and ν 7 is the very anharmonic CCC bending mode. Among these bands, 20 have been rotationally analyzed and 1220 lines assigned. The line positions were fitted to effective parameters which characterize these 20 vibrational levels in the ν 6 state. The results of the fits were then fitted so a semirigid bender model in order to determine the effective CCC bending potential function in the ν 6 state.