Microvawe-spectrum and ab initio computations for ethylene carbonate. 2. Electric dipole moment

The electric dipole moment of ethylene carbonate has been determined from Stark-effect measurements in its microwave spectrum as 5.35 ± 0.15 D. The breakdown of second-order perturbation theory made it necessary to use a full matrix diagonalization treatment in order to obtain consistent results. Anomalous Stark effects are observed for the M= 1 and 2 components of the 3_03<- 2_02 transition and are analysed in terms of changes in the rotational wavefunctions. The high electric dipole moment and the electronic structure of ethylene carbonate are discussed using ab initio wavefunctions.