Dipole moments of some aromatic and aliphatic aldehydes. Their dependence on the solvent and the atomic polarization
The dipole moments of 21 aromatic and aliphatic aldehydes were determined. Permittivity measurements were performed on highly diluted cyclohexane solutions at 20 °C. The limiting forms of Debye's, Onsager's, and Bordewijk's expressions were used. The influence of the solvent on the dipole moment values was studied using decalin and heptane mixtures. Only the Debye's values presented an apparent solvent effect while the Onsager's and Bordewijk's values remained independent of the solvent. Dipole moment values obtained using the refractive indexes of the components were also compared with those derived using the refractive indexes of the mixtures. This permitted one to estimate in 0.07 the relation between atomic and electronic polarization.