Microwave Spectrum of Chlorine Dioxide. IV. Determination of Centrifugal Distortion Effects and Potential Constants

A reanalysis of the microwave spectrum of chlorine dioxide, taking into account the effects of centrifugal distortion, has been carried out. When the centrifugal distortion constants are forced to be consistent with the harmonic vibrational frequencies obtained from the visible spectrum, 18 rotational transitions of Cl35O2 are fitted with a standard deviation of 2.5 Mc. The rotational and force constants obtained are A=52079.5±0.8 Mc, B=9952.23±0.15 Mc, C=8333.99±0.13 Mc, fd=7.0175±0.003×105 dyn cm—1, fα/d02=0.6514±0.002×105 dyn cm—1, fdα/d0=0.0064±0.0008×105 dyn cm—1 and fdd=—0.1699±0.003×105 dyn cm—1. The force constants were used to calculate the distortion shifts for the Cl37O2 molecule and the rigid-rotor frequencies for 7 rotational transitions of Cl37O2 were fitted with the rotational constants.