NOTES
1664
to base line, a t 61% I0B-39% 1% (1A) resolution has decreased markedly, and at 85% IoB-15% IIB (1D) individual multiplet lines are no longer readily distinguishable. The relative intensities of the central lines in spectra 1A and 1B were found to be 29:57:70: 57:29 f 1 in close agreement with the intensities calculated for the central lines of the nine-line multiplet expected to zrise from coupling with eight equivalent protons. Low signal to noise ratios made line intensity measurements of spectrum 1 D and the outermost four pe:iks of 1A and 1B difficult. I n each of the above cases, the spectra were observed over a sufficiently wide range of radiofrequency field amplitudes (35 to 55 db below 0.5 w) to establish that the observed resolution loss was not due to radiofrequency field (Hl) saturation effects. At low temperatures (ca. - 15”) resolution decreased, probably owing to increased viscosity of the diethyl ether solution. The IlB ninr spectra of the 617, 1°B-39% ‘lB and 85% l0B-l5$& 1lB NaB3H8 samples obtained when a strong radiofrequency field, HS,was applied a t the loB resonance frequency are shown in Figures 1C and 1E. I n these cases, “B-{’OB] double resonance was obtained by sweeping the magnetic field, Ho,and varying H2 until the maximum effect on the spectrum was observed. Evidence of line sharpening and increased peak intensi;ies was easily seen at H2 frequencies ranging froni 6.445890 to 6.445720 llclsec ; however, the optimum frequency appeared to be 6.445790 N c / sec i 1 0 cps. Within the limits of experimental error, the relative line intensities and 32-cps line spacings apFeared unchanged in the “B-{ log] decoupled spectra. Tet~aborane (B4H10). The high-field doublets of the IlB spevtra of 18.8% 1°B-81.2% llB and 61% ‘OB-397, ”El B4HI0 samples measured prior to IlB{‘OB) double irradiation are shown in Figures 2A and 2C, respectively. Considerable secondary structure is exhibited in the spectrum of the 18.8% loB-81.2% 1lB material (2A) which partially collapses as the IOB content of the tetraborane sample is i n ~ r e a s e d . ~Hence, a t 61% 10B-39y0 11B, a doublet ( J = 157 cps) exhibiting secondary broad triplet structure ( J = 47 cps) is obtained (2C). Applicatiort of l1B-t ‘OB} double resonance to the two B4Hlo samples resulted in the spectra shown in Figures 2B :md 2D. I n 2B, the two most intense center peaks show increased intensity relative t o the remaining fine structure lines and over-all resolution of the signal is improved; however, in 2D a doublet ( J = 159 cps) of triplets ( J = 50 cps) is clearly shown. The optimum decoupling frequency (Hz) for BdHlo was 6.445790 r\lc/sec + 10 cps. T h e Journal of Physical Chemistry
Acknowledgment. This work was supported by the n’ational Science Foundation and by the National Aeronautics and Space Administration in the form of a traineeship for A. N. The authors wish to express appreciation to Arthur 0. Clouse for assistance in obtaining nmr data.
Observations in Relation with Surface Phenomena of Rotating Liquids by 31. Borneas Faculty of Physics and Chemistry, Timisoara, R u m a n i a (Receiaed M a r c h 4, 1366)
We have shown in some preceding papers’ that if a liquid is in rotation (quasi-static state), the surface tension changes its value, depending on frequency and temperature. We called this phenomenon a “rotokinetic effect.” We have shown that with all of the liquids studied, at low temperatures the roto-kinetic surface tension is greater than the static surface tension, except some minima. Above a certain temperature, characteristic for each liquid, the roto-kinetic effect disappears. The appearance of an increased interaction a t the surface of rotating liquids suggests the formation and ordering of molecular groups. The problem of ordering in liquid crystals has been very interestingly treated in a recent paper.2 We assume that something analogous is happening jn all liquids, that is, a separation of liquids in “crystals’) and “noncrystals” cannot be so neat. I n our experiments the inertial field seems to be responsible for the ordering. However, a simple model of anisotropic and inhomogeneous groups which are directed under the centrifugal forces is not sufficient, because the roto-kinetic effect does not depend on the distance to the center of rotation. This we underline with the data presented in Tables I and I1 (errors ranging frclll 0.15 to 0.3%). We presume that the groups appearing in liquids are temporal since they are disuniting and re-forming, a fact which is admitted by other authors too.3 (1) & Borneas I. and E. Kalman, Compt. Rend., 245, 1710 (1957); 249, 1036 (1959); S t u d i i Cercetari C h i m . (Timipoara), 7, 353 (1960); .Vaturwiss., 47, 373 (1960); Acta P h y s . Polon., 20, 187 (1961). (2) R. JTilliams, J . Chem. Phys., 39, 384 (1963).
M.Borneas and I. Bhbufia, ibid.,
(3) E. Darmois, “L’ktat liquide de la matibe,” Albin Michel, Paris, 1943.
NOTES
1665
Koto-kinetic su Ethyl Alcohol (dy--- '--'
'1'abie I :
Tensiometer ring diameter, mm
5.48 6.18 7.38 8.53 10.38 13.58
c
Rotation frequency, rev/min 58 70 100
0
40
22.33 22.36 22.34 22.33 22.32 22.33
22.41 22.43 22.40 22.39 22.41 22.43
22.50 22.49 22.49 22.50 22.47 22.49
22.56 22.53 22.56 22.54 22.52 22.54
22.72 22.73 22.75 22.73 22.75 22.74
We have also tested the ability of several solid metal chlorides to catalyze vapor phase Friedel-Crafts reactions. 143
23.15 23.15 23.16 23.14 23.11 23.14
Table 11: Roto-kinetic Surface Tension of Butyl Alcohol (dynes/cm) at 21' Tensiometer ring diameter, mm
0
40
5.48 6.18 7.38 8.53 10.38 13.58
24.62 24.65 24.64 24.61 24.63 24.63
24.72 24.74 24.74 24.68 24.68 24.71
Rotation frequency, rev/min 58 70 100
24.80 24.80 24.76 24.79 24.79 24.79
24.85 24.84 24.86 24.88 24.82 24.85
25.05 25.07 25.05 25.08 25.04 25.06
143
25.55 25.59 25.58 25.55 25.57 25.56
At the temperature where the roto-kinetic effect disappears, there is a phase transition to a n isotropic liquid phase. No existing mathematical theory is suitable to explain the surface phenomena described above.
Experimental Section Gaseous HC1 was prepared from aqueous HC1(C136)by passing through PzOson a vacuum line. I t s specific activity was determined in a glass annular counting jacket which surrounded a thin-walled Geiger tube. It was then exposed to the metal chloride sample in a 30-ml flat-bottomed quartz reaction vessel, which could be heated to any desired temperature. Following exposure it was returned to the counting jacket for determination of the activity. By repeated exposures of the HC1 to the sample, followed by activity determinations, the exchange of C136was followed as a function of time and temperature. Transfers were made by freezing the gas into a tube on the desired vessel, with the aid of liquid nitrogen.
(1) This work was supported in part by the U. S. Atomic Energy Commission under Contract AT(l1-1)-32, by the W. F. Vilas Trust of the University of Wisconsin, and by a Danforth Foundation Fellowship. (2) Further details of the work are given in the Ph.D. Thesis of J. R. Wilson, University of Wisconsin, 1964, available from University Microfilms, Ann Arbor, Mich. (3) These include the exchange of chlorine between HC1 and NaCl,' AlCla: ZrCla,G and SnC14;' of chlorine between Clt and NaCl,' and AgC1;S of bromine between Brt and AgBr;g of fluorine in a number of gas-solid systems;10.11 of iodine between CHaI and AgI, F'dIz, TlIg, and PbI2;12 of bromine between CHaBr and BaBrt, CaBrt, and AlBr8;'a and of chlorine between alkyl chlorides and A1C13.14 (4) See for example and other references: (a) R. J. Adams and L. G. Harrison, Trans. Faraday SOC.,60, 1792 (1964); (b) L. W. Barr, I. M. Hoodlees, J. A. Morrison, and R. Rudham, ibid., 56, 697 (1960). (5) M. Blau, W. T. Carnall, and J. E. Willard, J . Am. Chem. SOC.,
Exchange of Chlorine between Hydrogen
74, 5762 (1952).
Chloride and Metal Chlorides1v2
(6) B. P. Dahlstrom, Jr., and J. E. Willard, unpublished. (7) R. A. Howald and J. E. Willard, J . Am. Chem. Soc., 77, 2046
by J. R. Wilson and J. E. Willard Department of Chemistry, University of Wisconsin, Madison, Wisconsin (Received A p r i l 19, 1966)
The exchange of halogen atoms between gaseous covalent molecules and a number of solid metal halides has been ~ b s e r v e d . ~ - lThat ~ such exchange should occur is in some ways surprising. There is no detailed knowledge of the nature of metal halide surfaces or adequate theory for predicting the probability of their reaction with covalent molecules. With the aim of determining whether there are significant differences
(1955). (8) F. J. Johnston, Ph.D. Thesis, University of Wisconsin, 1952. (9) (a) I. M.Kolthoff and A. S. O'Brien, J . Am. Chem. SOC.,61,3409 (1939); (b) I. M. Kolthoff and A. S. O'Brien, J . Chem. P h y s . , 7, 401 (1939); (c) N. Davidson and J. Sullivan, ibid., 17, 176 (1949). (10) (a) R. B. Bernstein and J. J. Katz, J . P h y s . Chem., 56, 885 (1952); (b) R. M. Adams, I. Sheft, and J. J. Kats, Proc. Intern. Conf. Peaceful Uses A t . Energy, 8 n d , Geneva, 20, 219 (1958); (c) I. Sheft, H. Hyman, R. M. Adams, and J. J. Katz, J . Am. Chem. Soc., 83, 291 (1961). (11) (a) T. A. Gens, J. A. Wethington, A. R. Brose, and E. R. Van Artsdalen, ibid., 79, 1001 (1957); (b) T. A. Gens, J. A. Wethington, and A. R. Brosi, J. P h y s . Chem., 62, 1593 (1958). (12) I. Galiba, L. Latzkovits, and D. Gal, M a g y . K e m . Folyoirat, 67, 323 (1961). (L3) G.-B.JCistiakowsky and J. R. van Wazer, J . Am. Chem. SOC., 65, 172Y (1943). (14) (a) C . H. Wallace and J. E. Willard, ibid., 72, 5275 (1950); (b) M. Blau and J. E. Willard, ibid., 73,442 (1951).
V o l u m e 70, Number 6
M a y 1966
