Conductance behavior of electrolytes in 1,3-dimethylethyleneurea and 1,3-dimethylpropyleneurea at 25�C

Abstract

1,3-Dimethylethyleneurea (DMEU) and 1,3-dimethylpropyleneurea (DMPU) were investigated as electrolytic media for a number of alkali metal and triisoamylbutylammonium salts via conductivity measurements over a concentration range of 1–100×10−4M at 25°C. The data were analyzed by the Fuoss-Shedlovsky, Fuoss-Onsager, and expanded Pitts equations. The limiting equivalent conductivities were about 1.5 times greater in DMEU than in DMPU, which is exactly the ratio of the viscosities. From the Fuoss-Onsager analysis, all salts studied were found to be essentially unassociated in both solvents. From the expanded Pitts equation the extent of association was small, but within a salt series the equation indicated that association decreased in the order iodides, thiocyanates > perchlorate > tetraphenylborates. Neither solvent differentiated between sodium and potassium ion mobilities, indicating a type of solvation behavior different from that in acyclic urea solvents such as tetramethyl- and tetraethylurea.