April 5, 1953
NOTES
existence of the 7- and &isomers4were not known a t the time of these experiments, these and possibly other isomers may have been formed in small amounts. Also, secondary isomerization of primary products undoubtedly affected the final Composition both qualitatively and quantitatively; the @-isomerin particular if formed should have largely isomerized to alpha. In view of these consideratioas the agreement of the observed results with those predicted appears sufficiently good to support the described mechanism. The e-, q- and @-isomershave not been available to us for isamerization so that we have not been able to use them to test the suggested mechanism. We gratefully acknowledge the aid of Messrs. W. R. Harp, Jr., and I?. S. Mortimer in making the spectroscopic analyses, and the suggestions of Dr. A. G. Kridl on the mechanism of isomerization.
D
(4) A. J. Kolka, H D. Orloff and M. E. Griffing, Abstracts of Papers, 121st Meeting of American Chemical Society, Buffalo, N. Y . ,
March 24-27, 1952.
ORGANIC SYNTHESIS DEPT. S R ~ LDEVBLOPMXNT L Co.
EMERYVILLB, CALIFORNIA
Tracer-diff usion in Liquids. IV. Self-dmusion of Calcium Ion and Chloride Ion in Aqueous Calcium Chloride Solutions' BY JUI H. WANO RECEIVED NOVEMBER 7, 1952
1769
vs. 4 curves for self diffusion to be quite different from that for salt diffusion. Furthermore, it should be of interest to see how the self diffusion coefficients for different ions in the same solution vary as the salt concentration of the solution increases continually up t o saturation. In the present work the self-diffusion coefficients of calcium ion and chloride ion in aqueous calcium chloride sohtions a t 25' have been measured by means of the improved capilIary method.
Experimental Radioective Tracers.-Cas and ClWwere used as tracers in the self-diffusion measurements. These were obtained from the Isotopes Division of the U. S. Atomic Energy Commission a t Oak Ridge, Tennessee. DiBusion Measurement.-The experimental techniques involved were already discussed in paper I of this series. The radioactivity of the diffusion samples was measured with a windowless, continuous flow counter. Since dry calcium chloride is hygroscopic in air, the calculated amount of sodium fluoride solution was added t o each sample before evaporation t o dryness under a n infrared lamp. The samples so prepared contained approximately equal amounts of dry residue (solid sodium chloride and calcium fluoride) and were kept in a desiccator overnight before counting. Since in the calculations t o obtain the diffusion coefficients only the ratio of the concentrations of radioactive tracers is involved, possible errors due t o self-absorption of p-radiation are automatically eliminated.
Results.-The measured self-diff usion coefficients of C a f + and C1- in aqueous calcium chloride solutions a t 25' are listed in Table I. Each value listed in Table I is the average result of a t least four measurements. TABLE I
The salt diffusion of calcium chloride in its aqueous SELF-DIFFUSION COEFFICIENTS OF Ca++ AND C1- IN CaCh solutions has been the subject of experimental study (aq.) AT 25' of many workers in the past fifteen years. The reConcentration Dcstt X 106, Dol- x 106, cm.=/sec. cm.¶/sec. sults obtained by Harned and Levy2 indicate that formular wt./liter the measured salt diffusion coefficients of calcium 0.0100 0.778*0.028 chloride are lower than the values computed from 1.89 f0.02 .0705 .782 f ,015 the Onsager-Fuoss theory in solutions of concen1 . 7 2 i .04 .282 .767 f ,008 tration between 0.001 and 0.005 formula weight per .025 1.60 f .04 ,803 ,646 liter. The salt diffusion coefficients of calcium 1.42 .f.03 1.41 ,560 f ,020 chloride in concentrated a ueous solutions have 0 . 9 0 7 3 ~ .020 .405f .015 2.68 been determined by Hollings ead and Gordona and 0 . 4 4 7 f .015 4.02 .225 f ,002 by Robinson and Chia4 by means of the diaphragm 0.159f .010 5.36 .IO0 i .009 cell method, and independently by Stokes and coDiscussion.-Using apropriate units the Onsager workers6 and by Lyons and Riley6 by means of the optical method. Their results show that in cal- equation may be written as7 cium chloride solutions of concentration above 0.2 formular weight per liter the salt diffusion Coefficient increases with increasing salt concentration up to about 2.2 formular weight per liter. This phenomenon has generally been attributed to the continual where Dj is the tracer-diffusion coefficient of ions decrease of the activity coefficient of the salt along of the jth kind in a salt solution, 2% is the charge in the diffusion path. I n self-diffusion, however, the electronic units and q the concentration in moles chemical composition and hence the activity' coef- per liter of ion i, X,O the limiting equivalent conductficient of the diffusing ions is constant along the ance of ion j , 6 ) the dielectric constant of the soldiffusion path, the theoretical relationship between vent R the Boltzmann constant, 5 the Faraday the diffusion coefficient and salt concentration be- constant, T the absolute temperature, and d(pj) a comes simpler and we may expect the shape of the function given by -
*
4,
(1) Contribution No. 1134 from the Department of Chemistry of Yalt University: Paper I, THXS JOURNAL, 74, 1182,6317(1962); paper 11, 74, 1611 (1952); paper 111, 74, 1612 (1952). (2) H. S. Harned and A. L. Levy, ibid., 71,2781 (1949). (3) E. A. Hollingshead and A. R. Gordon, J. Chsm. P h y s . , 9, 152
(1941). (4) R. A. Robinson and C. L. Chis, THIS JOURNAL, 74, 2776 (1952). ( 5 ) Hall, Wishaw and Stokes.private communication. (6) P. A. Lyons and J. F. Riley, private communication.
d(w.)
1 - +ZP
cilZi/Xio (XiOllZCl) ('i~//Z~O
1
+
(2)
For the diffusion of tracer amount of ions of species 1 in salt solution containing ions of species 2 and 3, we have (7) See paper I or I1 of this series.
VOl. 7 5
NOTES
17iO E0
exists in the transference number data of calcium ion in dilute aqueous calcium chloride solutions.* The general shapes of the curves in Fig. 1 are in and hence (2) can be written as apparent agreement with the general qualitative interpretation suggested in the three preceding papers of this series.l Thus because of the larger mean (3) radius of the hydrated calcium ion and the fact that If we take A&- = 76.36, A:,++ = 50.4, and using calcium chloride is a 2-1 electrolyte, all the prethe relationship cc,Z: = Gc where c is the salt con- viously mentioned “distortion-effect” on the structure of solvent water, “effect of sharing of hydra2 centration in forniular weight of CaC12per liter of tion,” etc., should become important a t lower formular concentration of the salt for calcium chlosolution, we obtain by combining (1) and (3) ride than for sodium or potassium chloride solutions. Dca++x 10’ = 0.791 - 0.808 ,’? (4) It may also be noticed from the values listed in and Table I that the ratio of the self-diffusioncoefficient Dci- X lo5 = 2.033 - 1.729 l / C (5) a t infinite dilution to that in 5.3G formular wt. per for the self-diffusion of Ca++ and C1-, respectively, liter calcium chloride solution is approximately 13 for C1- and 8 for Ca++. The ratio of viscosity of in dilute calcium chloride solutions. Values of D C a + + X lo5 and Del- X lo5 are 5.36 formular wt. per liter calcium chloride solution plotted os. c< in Fig. 1. The two straight lines in to that of pure water at 25’ is about 11. the dilute concentration range represent equations Acknowledgment.-This work was supported by contract AT(30-1)-1375 between the U. S. Atomic (4) and (5) , respectively. Energy Commission and Yale University. When preparing the present manuscript, the author benefited through discussion with Professor H. s. 2.0 Harned. c1
C?
1z2 1
=
c3
/z2j
(8) H S. Harned and B. B. Owen, “Physical Chemistry of Electrolytic Solutions,” 2nd Ed., Reinhold Publ. Corp., New York, N. Y., 1960, p. 164
1.5
Local Anesthetics. III. Modifications of 8’4Methylphenoxyethyl p-N-Methylbenzylaminoethyl Ether
5 X
9
DEPARTMENT OF CHEMISTRY YALEUNIVERSITY SEW HAVEN,CONNECTICUT
1.o
BY HOWARD B. WRIGHTAND M. B. MOORE RECEIVEDDECEMBER 5, 1952
In papers I and I1 we have reported that the salts of aryl alkamine ethers ArOR’NR21a and aryloxyalkyl alkamine ethers AI-OR’OR‘’NRZ~~in which Ar is an aryl, R’ and R ” are alkylene and R 0..5 is an alkyl or aralkyl group, have been tested as local anesthetics. As a continuation of this work, we have now prepared a number of compounds related to 8-4-methylphenoxyethyl d‘-N-rnethylbenzylaminoethyl ether which was reported in paper I1lb to produce good corneal anesthesia. 0.0 Table I lists the compounds synthesized, with 0.0 04 0.8 1.2 1.6 2.0 2.4 pertinent physical and analytical data. ‘Solutions of hydrochlorides or other salts of these ethers were 4. Fig. 1.-Self-diffusion coefficient of C a + + and C1- in tested for local anesthetic activity by Dr. R. K. CaClz (as.) at 25”: 0 , self-diffusion of C1-; 0,self-diffusion Richards and his staff to whom we are indebted. All these ethers displayed corneal and wheal of Ca++. anesthesia but the activity was accompanied by It can be noticed from Fig. 1 that as the concen- some irritation. Experimental tration of calcium chloride solution decreases conThe o-diphenoxyethoxyethyl chloride was prepared in tinuously to zero the self-diffusion coefficients of yield by a method Bruson2 developed for analogous both e a + + and C1- appear to approach the Nernst’s 47.5% compounds. The boiling point of an analytical sample limiting values from above the two straight lines was 162’ (1.0 mm.), n% 1.5792. representing Onsager’s equations (4) and (5). This Anal. Calcd. for C~H27C102: C , 69.43; H , 6.19; C1, tendency of approaching the limiting value from 12.81. Found: C, 69.51; H,6.29; C1, 12.81. above Onsager’s equation appears to be especially (1) (a) H. B. Wright and M. B. hfoore, THISJOURNAL, 73, 2281 apparent in the self-diffusion of calcium ion. I t is (1051), (b) 73. 5526 (1951). interesting to recall that an analogous behavior ( 2 ) I1 A Drusen, U S Patent 2,113,2Xl, April ZG, 1‘338.
