366
Vol. 61
NOTES THE CHLORINE TRIFLUORIDE-HYDROGEN FLUORIDE SYSTEM. SOME VAPOR PRESSURE AND CONDUCTANCE MEASUREMENTS' BY MAX T.
ROQERS,
JOHNL. SPEIRSAND MORTONB.
PANISH
Kedplie Chemical Laboratory. Michiaan Slots University, East Lansing Michigan Received September 80, 1066
The possible existence of a stable complex between chlorine trifluoride and hydrogen fluoride2 made further study of this system desirable. We have therefore investigated the vapor pressures and specific conductances of liquid solutions of hydrogen fluoride in chlorine trifluoride. The vapor pressure-composition data a t 0" are shown in Table I.
TABLE I1 CONDUCTANCES OF CHLORINETRIFLUORIDE-HYDROQEN FLUORIDE SOLUTIONS AND OF CHLORINE TRIFLUORIDE AT 25 and -78' C (moles HF/l. at 26O)
0 1.00 1.35 2.57 4.67
L,ohms-1 om. -1 x 108
-780
26O
0.65 4.5 9.5 82.5 460
0.49 2.96 5.49 43.7 350
A X 10' (at 25")
0 0.25 0.45 1.68 7.5
cc./mole which is 3.3% smaller than the ideal average molar volume (35.0 cc./mole). This is close to the observed decrease in volume found in other hydrogen fluoride-halogen fluoride systems6; molar conductances h were calculated with the aid of this result.
Experimental TABLE I Materials.-Chlorine trifluoride and hydrogen fluoride THE VAPOR PRESSURESOF CHLORINETR~FLUORIDE(Harshaw Chemical Co.) were purified by a simple distillation in Monel apparatus. For conductance work the hyHYDROGEN FLUORIDE SOLUTIONS AT Oo drogen fluoride was dried over cobaltic fluoride (L 2 -9 X Mole Pressure, Mole Preseure, % HF mm. % HF mm. lO-'ohm-' om.-' at 25"); Our data provide no evidence for the existence of a stable 0.0 448 89.0 645 corn lex between chlorine trifluoride and hydrogen fluoride. 10.6 562 86.0 527 WhiL it is possible that such a oom lex exists as a transient 33.2 592 100.0 398 intermediate in exchange reactions ilevidently does not exist in important concentrations at room temperature. The system shows large positive deviations from Apparatus and Method.-These were essentially the mme Iiaoult's law a t this temperature. There is an azeo- as described elsewhere.610 All measurements were made as tropic mixture with maximum vapor pressure the soon as possible after the mixtures were prepared.
-
composition of which is about 65 f 10 mole % hydrogen fluoride.a Although the probable error in our pressure measurements was not over zt5.0 mm. we would not claim an accuracy in the vapor pressures better than about =k3% since there was some evidence of reaction of the materials with the apparatus and consequent drift of pressure with time. The specific conductance of chlorine trifluoride and of various solutions of hydrogen fluoride in chlorine trifluoride at 25 and -78" are shown in Table 11. The specific conductance of chlorine trifluoride may be compared with an unpublished value4 of 3 X ohm-' cm.-l a t 0". The addition of hydrogen fluoride increases the conductance markedly but molar conductances are low indicating a low degree of ionization. A measurement of the density of a single solution (53.0 mole % hydrogen fluoride, d26* 1.60 g./cc.) gave an observed average molar volume of 33.8
(1) Physical Properties of the Halogen Fluorides. X. For the preceding article of this series see M. T. Rogers and J. L. Speirs, THIS JOURNAL., 60, 1462 (1956). (2) D. F. Smith and J . P. Pernslcr, "Symposium on Spectroscopy," Ohio State Univeraity, June 18. 1954; M. T. Rogers and J. J. Katc, J . A m . Chem. SOC.,74, 1375 (1952). (3) An aaeotrope oontaining 67 mole % ' hydrogen fluoride has been reported recently by another method; R. M. McGill, W. 8. Wendolkowski and E. J. Barber, Abstracts of the 126th National Meeting of the American Chemical Society, New York,N. Y., September, 1964. (4) A . A. Banks quoted by N. N. Greenwood, Revs. Pure and Applied Chem. (Australia), 1, 84 (1851).
Acknowledgment.-This work was supported by the Atomic Energy Commission through contract AT (11-1)-151. ( 5 ) M. T. Rogers, J. L. Speirs and M. B. Panish, J . Am. Chem. Soc., 7 8 , 3288 (1958); M. T. Rogen, J. L. Speirs. M. B. Panish and H. B. Thompson. ibid., 78, 936 (1966). (6) H. B. Thompson and M. T. Rogers, Rev. ScS. Instr., 117, in press.
THE ELECTRIC MOMENTS OF LITHIUM-ALKYLS BY MAXT. ROQERS AND T. L. BROWN' Kedeie Chemical Laboratory, Michigan State University. East Lansing, Michtgan Received September 7 , I866
The only electric moment measurement reported for an organolithium compound is the value 0.97 D. computed for n-butyllithium by Rogers and Young2from the measured dielectric constants of a series of solutions of n-butyllithium in benzene. The3 assumed that the compound was a monomer but it is now known that these compounds are polymerized in benzene solution.a In view of the interest in the carbon-lithium bond moment, and (1) DuPont Teaohing Fellow, Michigan State University 19551966; Noyes Chemical Laboratory, Univeraity of Illinois, Urbana, Illinois. (2) M. T. Rogers and A. Young, J . A m . Chem. Sdc., 68, 2748 (1946). ( 3 ) E. Warhurat, Disc. Faraday Soc., 11, 239 (1947).
