Dielectric constants, viscosities, densities, and refractive indices of three urea derivatives were measured at various temperatures ranging from 25 to 100 °C. The experimental data as functions of temperature were fitted precisely to appropriate equations. Dielectric constant data indicated a significant increase in dielectric constant of the cyclic ureas over that of the acyclic homologs. Kirkwood correlation factors and the activation energies of viscous flow were also evaluated. Values for Kirkwood correlation factors ranged from 1.07 to 1.21. This range indicates but does not substantiate parallel dipole association. Activation energies ranged from 3.3 to 4.4 kcal/mol.

No abstract

Nonvolatile hydrocarbons in Atlantic Ocean and nearby waters were found to contain aromatics at lower concentrations than would be expected if the source of the hydrocarbons were crude oil or petroleum refinery products. Hydrocarbons appear to persist in the water to varying degrees with the most persistent being the cycloparaffins, then the isoparaffins, and finally the aromatics.

Conductance measurements for a series of tetraalkylammonium salts in 3-tertbutyl-2-oxazoíidone (3f Bu20x), a recently synthesized nonaqueous solvent of exceptionally high purity, were made over a relatively wide concentration range (2-200 X 10~4 M) at 25°. All conductance data were evaluated by the Fuoss-Onsager equations for associated and unassociated electrolytes and by the expanded Pitts and Fuoss-Hsia equations. From the Fuoss-Onsager data analysis, which yielded unrealistically small ion size parameters, all of the tetramethylthrough tetrahexylammonium tetraphenylborates, perchlorates, bromides, nitrates, and picrates were found to be unassociated electrolytes in 3tBu20x. From the expanded Pitts and Fuoss-Hsia equations with values of the ion size parameter ranging from 3 to 9 Á, small association constants ranging from 0.4 to 9.2 M~1 were obtained for these electrolytes. Association within the salt series decreased in the order nitrates > bromides > perchlorates > tetraphenylborates. The same values of the electrolyte limiting equivalent conductance were obtained from the two expanded equations; however, these Aq values were slightly smaller than the values obtained from the Fuoss-Onsager equations. Ionic limiting equivalent conductances were obtained by using triisoamylbutylammonium tetraphenylborate as a reference electrolyte. Generally, the limiting equivalent conductances of the tetraalkylammonium ions decreased as the crystallographic radii of these ions increased; but surprisingly, the + value of the tetraethylammonium ion was higher than that of the tetramethylammonium ion in 3t Bu20x. 5 .464-202.6 (15) 0 .009 9 .34 ± 0 .023 2 .2 dr 0 .17 Me4NPi 5 .6 5 .216-95.90 (6) 0 .004 12 .29 ± 0 .011 2 .9 dr 0 .13 4 ,9 49 .67-163.8 (6) 0 .004 12 .43 ± 0 .014 2 .3 dr 0 .09 5 .216-163.8 (12) 0 .009 12 .32 ± 0 .025 2 .9 dr 0 .18 Et4NC104 3 .5 9 .964-91.04 (6) 0 .006 15 .07 ± 0 .022 2 .5 dr 0..22 8 .2 21 .76-179.6 (6) 0 .004 15 .16 ± 0..015 1 .9 dr 0..07 9 .964-179.6 (12) 0 .005 15 .12 ± 0 .012 2 .1 dr 0.,06 EtiNNOs 5..6 13 .09-128.0 (9) 0 .004 15 .94 ± 0 .012 0 .8 zb 0 .05 Pr4NBPh4 8 .8 16 .65-88.40 (7) 0 .002 8 .12 ± 0 .008 3 .4 zb 0..14 Pr4NC104 6 .7 6 .436-101.1 (7) 0 .002 13 .74 ± 0 .006 2 .0 zh 0 .06 Pr4NBr 3 .5 13 .30-99.80 (7) 0 .003 13 .20 ± 0 .011 0 .6 dr 0..06 8 .2 21 .28-181.5 (7) 0 .006 13 .20 ± 0 .020 0 .5 dr 0 .05 13 .30-181.5 (14) 0 .004 13 .20 ± 0 .009 0 .5 rfc 0 .03 Bu4NBPh4 12 .0 56 .59-165.3 (7) 0 .002 7 .50 ± 0 .009 2 .8 zh 0 .08 Bu4NC104 3 .5 15 .13-78.60 (5) 0 .004 13 .08 ± 0 .014 2 .1 dr 0 .17 8 .2 63 .45-162.1 (5) 0 .004 13 .13 ± 0 .016 1 .9 zh 0 .09 15 .13-162.1 (10) 0 .004 13 .09 zh 0 .011 2 .1 zb 0 .08