Twenty derivatives of N,N-dialkyl perfluoroalkanesulfonamides, n-CmF2m + 1SO2NRR′ (m = 1, 2, 4, 6, 8; R, R′ = CH3, CH2CH3 or CH2CH2OCH3), have been prepared and characterized. Their fundamental physicochemical properties, including melting point, density, viscosity and dielectric constant, are determined. The influences of structural variations in both the perfluoroalkyl and alkyl chains on the above