MICROWAVE ABSORPTION AND MOLECULAR STRUCTURE IN LIQUIDS .74. DIELECTRIC RELAXATION MECHANISMS OF ALKYL ETHERS AND DIDODECYL SULFIDE

The dielectric constants and losses of heptane solutions of ethyl, dihexyl, didodecyl, and dodecylmethyl ether and didodecyl sulfide have been measured at wavelengths of 0.2, 1.2, 3.2, 10.0, and 25.0 cm and 30 000 m at temperatures between 6° and 50° and used to calculate the dielectric relaxation times of the liquids. With one exception, the results for each liquid can be analyzed into a long relaxation time associated with rotational orientation of the molecule as a whole and a short relaxation time for dipole orientation by intramolecular motion. In the case of the small ethyl ether molecule, the difference between the size of the small molecule and those of its intramolecular polar groups is insufficient to permit any observable separation of relaxation processes. The considerable sizes of the atomic polarization values suggest contributions to infrared absorption by twisting around the C C bonds. © 1969, American Institute of Physics. All rights reserved.