The dielectric constants and losses at wavelengths of 0.428, 0.860, 1.249, 1.850, and 3.220 cm and the static dielectric constant at 149.9 m have been measured for methoxypentafluorobenzene, pentafluorobenzene, trifluoromethoxybenzene, and anisole in cyclohexane solutions at 25deg;C. Measurements were also carried out on trifluoromethoxybenzene in decalin solution at 25deg;C. Dielectric relaxation times have been evaluated and the results for methoxypentafluorobenzene, trifluoromethoxybenzene, and anisole have been interpreted in terms of two relaxation times, one corresponding to molecular rotation and the other to intramolecular group rotation. Consideration has been given to the shortening of the methoxy group relaxation time in the pure liquid state compared with that in dilute solution. Mesomeric moments have been estimated from the dielectric data.
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