J. Pbys. Cbem. 1980, 84, 309-314
809
(3) I n ref 2 is reported the koHtin 2-BuOH but not in t-BuOH as reported ethanol where the p& decreases from 4.122in anhydrous by M. K. Chantooni and I. M. Koithoff in ref 1. solvent to 3.4923in a hydroalcoholic mixture containing (4) C. Contreras-Ortega, C. Nash, and P. Rock, J. Solution Cbem., 5, 0.19% of water. 133 (1976). (5) B. E. Conway, J. 0. M. Bockris, and H. Linton, Jr., J . Pbys. Cbem., The In MySEW depends on the solubility of HPi in al24, 834 (1956). cohols and decreases with increasing solubility. Now the (6) J. T. Edward, J. Cbem. fduc., 47, 261 (1974). presence of water in alcohols gives an increase in the (71 A. Bondi. J. Phvs. Cbem.. 68. 441 (1964). solubility of HPi and consequently a decrease in In MrsHpi. (8) R. De Lisi, M. Gffredi, and V. Turco Lberi, j . Cbem. Soc., Faraday Trans. I, 74, 1096 (1978). Then the anomalous value for this parameter in 2-PrOH, (9) M. Goffredi, Atti Accad. Sci. Lett. Arfi Palermo, Ser. I V , 27 smaller (about 0.4-0,5 unit) than that expected from a ( 1966- 1967). comparison with the other alcohols,’ can be due to the (10) R. De. Lisi and M. Goffredi, flectrocbim. Acta, 16, 2181 (1971). (11) R. De Lisi and M. Goffredi, J. Cbem. SOC.,Faraday Trans. 1 , 70, water content in the alcohol. 787 (1974). From the sum of the probable effect of water content (12) R. De Lisi, M. Goffredi, and V. Turco Liveri, J. Cbem. SOC.,Faraday (0.4-0.5 unit) and that on the (0.170) on the In MySHpi Trans. 1, in press. (13) R. De Lis1 and M. Goffredi, flectrocbim. Acta, 17, 2001 (1972). MASpKd(HPi)(0.3-0.4 unit) a more reliable value for In (14) M. Goffredi and T. Shedlowsky, J. Pbys. Chem., 71, 2182 (1987). MyHtS can be obtained. (15) D. K. McGuire, Diss. Abstr., 26, 116 (1965).
Acknowledgment. The authors acknowledge support of this work by the C.R.R.N.S.M. (Comitato Regionale per le Ricerche Nucleari e di Struttura fell0 Matereo).
References and Nates (1) M. K. Chantooni and I. M. Kolthoff, J. Phys. Chem., 82, 994 (1978). (2) R. De Lisi, Mi. Goffredi, and V. Turco Lweri, J . Cbem. Soc., Faraday Trans. 1, 72, 436 (1976).
P. Walden, H. Ulich, and G. Bwch, 2.phys. Chem., 123,429 (1926). G. A. Forcier, Ph.D. Thesis, University of Massachusetts, 1966. T. Shedlowsky, J . Am. Chem. Soc., 54, 1411 (1932). D. F. Evans and R. L. Kay, J . Phys. Cbem., 70, 366 (1966). W. Dannhauser and L. Bahe, J. Chem. Phys., 40, 3058 (1964). J. Brauman and R. Blair, J . Am. Cbem. Soc., 90, 6561 (1968). G. Chariot and 8. Tremilion, “Chemical Reactions in Solvents (and Melts”, Pergamon Press, New York, 1969. (23) P. Majersky and M. Dybalova, Acta Fac. Rerum Nat. Univ. Comenianae, Cbim., 22, 99 (1975).
(16) (17) (18) (19) (20) (21) (22)
Conductance and Infrared Studies on Acetonitrile Solutlons Containing Crown Ethers and Alkall Metal Salts Harry P. Hopkins, Jr.;
and Alan B. Norman
Bparfment of Chemisfty, Georgia Sfate Univefsity, Atlanta, Georgia 30303 (Received May 17, 1979)
Conductance studies have been performed on acetonitrile solutions of LiI, NaBPh4,and KBPh4at difference concentrations of 12-crown-4,15-crown-5,18-crown-6,and TM-12-crown-4. Upon the addition of these crown ethers to the LiI solutions, the equivalentconductance increases. A decrease is observed for similar experiments with NaBPhl and KBPh4 solutions. Infrared studies were performed in the 500-200-~m-~ region, leading: to the unambiguous conclusion that the crown ethers are complexing the lithium cation. A model for the solvation of the lithium ion is proposed to account for the increase in conductance found for the lithium salts. Since a 1:l solid complex is isolated from the acetonitrile solutions containing LiBr and 12-crown-4or 15-crown-5, the compositionof the complexes in solution is assumed to be 1:l. Analysis of the conductance data at different mole ratios of crown ether to salt provides equilibrium constants for the 1:l association complex. For the lithium cation these are in the order: Keq(12-crown-4)< Keq(15-crown-5)C Keq(18-crown-6),whereas for the sodium cation Keq(12-crown-4)
