Potential constants of nitrous oxide

Abstract

Least squares estimates of compliance constants, force constants, and interaction coordinates have been calculated for nitrous oxide from recent literature values of vibrational frequencies and centrifugal distortion constants of isotopic species. Mean square amplitudes and Coriolis coupling constants have also been calculated. Observed amplitudes have not been reported; however, the observed Coriolis values for 14N 14N 16O are in reasonable agreement with the calculated values. It is shown that for mean square amplitudes to be useful in the least square calculations of the potential constants they would have to be known within a few per cent, which is not likely with present-day electron diffraction techniques. The interaction coordinates tell us that if the NO bond length is constrained in a configuration longer than its equilibrium length, the resulting electron rearrangement would lead to a shortening of the NN bond, for minimum energy, equal to 6% of the NO displacement [that is, (NN) NO = −0.06]. Similarly, (NO) NN = −0.096. The average of (NN) NO and (NO) NN is equal to the interaction coordinate of CO 2, in accord with the similarity in bonding.