Charge separated states dipole moment

Electrooptical emission measurements in the gas phase12 show that the TICT state with its anomalous emission can be reached independently of any solvent environment (thus its formation is a true intramolecular phenomenon), and that the observed excited state dipole moment is consistent with a large degree of intramolecular charge separation. 

Ferroelectrics are also members of the 20 point groups that have no inversion center. Noncentrosymetric crystals may not have a dipole moment in their relaxed state, but when distorted, the center of negative charge is separated from the center of positive charge and a dipole moment results. Such crystals are piezoelectrics. All ferroelectrics and pyroelectrics are also piezoelectrics, but not all piezoelectrics are ferroelectrics. Piezoelectrics are used in strain and pressure gages, accelerometers, microphones and speakers, and linear actuators. 

Since the dipole moments of cyclopropenones are enlarged with respect to simple ketones and compare to other polar systems, e.g. trimethylamine oxide in Table 4, there seems to be evidence for considerable charge separation in the carbonyl group, which was expressed in terms of a cyclopropenium oxide contribution to the ground state. 

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