NOTES
June, 1956 TABLE I (CALCULATED FROM THE SPACINGS OF 1IIUIfER ORDERS) O F A SELECTION OF COMPLEXES OF MONTMORILLONITE
AfEAN 1'1IE
809
001
180. I
SPACINGS
Complexing substance
Obsd. doat (f0.1 kX.)
Type A Tetrahydropyrrole Piperidine hydrochloride a-Methylpiperidine hydrochloride a-Methylcyclohexanone
13.3 13.3 13.5 13.6
Type €3 Tetrahydrofuran Piperidine Cyclohexanol Cyclohexanone
14.6 14.7 14.6 14.8
tion with an approximately coplanar arrangement of the ring atoms.2 TABLE I1 OBSERVEDSTRUCTURE FACTORS OF THE 001 REFLECTIONS OF THE TETRAHYDROPYRROLE A N D PIPERIDINE COMPLEXES 'THE SIGNS BEING ALLOCATED FROM CALCULATIONS ON TRTAL STRUCTURES Tetrahydropyrrole
00 1 002 003 004 005 006
24 6
Bi
37 12 14
Piperidine
27 -_0 20 15 24 0
007 008 009
00,lO 00,ll 00, 12
Tetrahydropyrrole
Piperidine
..
13 10 0 8 10 6
22 8 11 17 9
...
Type B complexes have similar 001 spacings to the corresponding aromatic complexes and this is consistent with a reoriented molecule with its plane perpendicular to that of the sheet. Figure 1 (b) shows an electron density sketch of the piperidine complex and whilst the details are not resolved it seems to confirm that the intercalated molecule is oriented with its plane perpendicular to the silicate sheets. The spacings of type B complexes are nearly constant and this clearly indicates that the oxygen atoms in the cyclohexanol and cyclohexanone complexes do not determine the separation of the silicate sheets. As with similar aromatic complexes it therefore seems unlikely that hydrogen bonding of the organic hydroxyl group takes place to the silicate oxygens. Attempts to produce type B complexes of more complex molecules (e.g., a-methylpiperidine) were not successful as with aromatic molecules (e.g., a-picoline) and in all cases type A complexes resu1ted.I It is interesting to note that the calculated4 001 spacings of type A complexes of 14.4 kx.and type B of 16.0 kx. are over 1 A. greater than the observed values. This effect has also been observed with aromatic complexes and is suggestive that the projected van der Waals contact distances6 as(2) The limited number of observed 001 reflections clearly do not permit any conclusions concerning ring puckering as suggested b y Pitzer.8 (3) K. S. Pitzer, Science, 101, 672 (1945). (4) Assuming a random arrangement of moleculea between the ailicate sheets in otientationa analogous to those of aromatic complexes.1 (6) L. Pauling, "Nature of the Chemical Bond," Cornell Univ. Press, Ithaca, N. Y., 1944.
Fig. I.-The result of a one-dimensional Fourier synthepis of: (a) tetrahydropyrrole complex d ~ =, 13.3 kX.; (t)) piperidine complex dWl = 14.7 kX. Note the spurior1.s peaks a t X dge to the short sequences used in the synthesis. The deduced orientation of the intercalated molecule i H shown.
sumed between the silicate sheet oxygens and the organic molecules are too large.
A NOTE ON VISCOSITY OF MIXTURES. 11. LIQUID-LIQUID TERNARY MIXTURES BY R. P. SHUKLA A N D R. P. BHATNAGAR Department of Chemislry, Holkar College, Indore, India Received December 6 , 1966
The viscosity equation (TJm)'/a
=
d(r,R,
+ szRz +.
* * ' * *
*+ZnRn)
MIl
recently suggested' has been tested for ternary liquid-liquid mixtures. Experimental.-All the liquids taken were of Analar quality of the British Drug House; however, they were distilled again and the fractions distilling a t the correct boiling point were collected in glass-stoppered Pyrex flasks, Ethers and alcohols were kept over dry pure NaOH to keep them moisture free; the hydrocarbons were dried by keeping them over sodium wire. The viscosity was determined by an Ostwald viscometer and was multiplied by the viscosity of water to get absolute viscosity. Table I gives the viscosity as calculated and determined. (veal is the calculated viscosity and TJob. is the viscosity observed, while z,d and M , have usual meaning.)
Conclusion.-It will be seen from the table that the maximum error possible is of only 4% and hence it may be concluded that the viscosity of ternary mixtures can also be calculated from the equation suggested by us. Hence as there are no limitations for the number of components we can conclude that viscosity of any liquid mixtures can be cal(1) R. P. Shukla and R. P. Bhatnagar, (1966).
THISJOURNAL,69, 888
NOTES
810
Vol. 60
TABLEI Temp.. System
O C .
XI
x
“d”
Xa
XP
103
oal.
IWrn
1)
x
108
obs.
(I) GHR-CH~OH-C~H~ 35.0 0.1467 0.1506 0,7025 0.8618 73.10 5.187 5.10 ,2524 .6572 ,8549 71.20 5.556 5.60 (2) C~HB-C~H~OH-CBH~ 35.0 ,0905 (3) C?Hs-C&-CC14 55.0 ,7929 ,1385 ,0688 ,8946 94.34 5.171 5.171 .1933 ,6227 ,8507 63.55 5.385 5.60 (4) CH30H-C?HjOH-CiHs 35.0 ,1840 .2541 .2413 ,7874 41.83 4.948 4.82 (5) C€I~OH-C?H~OH-CHBCOCH, 4 5 . 0 ,5048 .0834 ,8395 .7916 35.16 5.346 5.25 35.0 ,0771 (6) CH~COCH~C~HBOH-CH~OH (7) CCla-CeHe-C7Hs 35.0 .0688 .1385 .go46 ,9046 94.34 5.515 5.64 (The Rheochor of substances taken in calculations were: toluene, 133.0; methyl alcohol, 49.9; benzene, 109.8; ethyl alcohol, 75.59; carbon tetrachloride, 122.0; acetone, 85.0.)
culated if the densities and viscosities of the component are known. GASEOUS METAL NITRIDES. 11. THE VAPOR PRESSURE OF GaN(S) AND EVIDENCE FOR A COMPLEX GASEOUS
NITRIDE BY RODNEY J. SIMEAND JOHNL. MARGRAVE Department of Chemistry, University of W i a c o ~ ~ s iMadason, n, Wi~iscon8in Received December 1 , 1066
weight losses extrapolated to zero flow rates for the calculation of vapor pressures listed in Table I1 where GaN(g) is assumed to be the vaporizing molecule.
TABLE I VAPORIZATION OF GaN(s) . _ Temp.,
Flow
K.
gas
1170 1170 1353 1353 1353 1420 1430
N2 Nz N2 N? He Nz
VOl. of
Flow rate, ml./min.
flow gas, 1. at S.T.P.
Wt. loss,
17 58 50 75 200 22 36
24.5 62.0 21.3 50.2 136.0 6.6 14.0
0.0008 .0005 .0178 .0309 .0423 .0247 ,0562
g.
In a previous paper1 the importance of gaseous diatomic nitrides was discussed, and dissociation energies for diatomic metal nitrides were calcu1JZ lated. Recently, the chemistry and thermodynamic properties of the nitrides of the elements TABLEI1 also have been reviewed.2 In the description of VAPOR PRESSURE OVER GaN(s) ASSUMING GaN(g) AS THE methods for preparation of GaN(s) in the literature VAPORIZING SPECIES there are comments about the “volatility” of GaN Pressure (extrapolated to in the NH3 flow gas used during f ~ r m a t i o n . ~ Temp., zero flow rate), This behavior appears to be unusual since most stm. OK. solid nitrides presumably decompose to the ele4.8 x 1170 ments on heating. A careful study of this vapor5 . 4 x 10-4 1353 ization phenomenon has been made. 1425 1 . 7 X lo-* GaN(s) is most conveniently prepared by passOne may show from thermodynamic arguments, ing NH3(g) over Ga(1) in a porcelain boat at 1000°. I n many runs essentially quantitative conversion however, that GnN(g) is probably not the principal was obtained if one took into account the extensive gaseous species. From available datal1v2one may transfer from the porcelain boat and the yellow- estimate free energy functions and a heat of forgrey deposits of solid GaN (from X-ray patterns) mation for GaN(g); the free energy function for found downstream from the boat. No GaN(s) is GaN(s) is very likely close to that of ZnO(s), a formed when N2(g) is passed over Ga(1) a t 1000°. compound of similar formula and of approximately A t 1000° the vapor pressure of liquid Ga is about the same formula weight. At 1500°K., for the 3 X atm. and transfer of Ga by a non-reactive reaction GaN(s) = GaN(g) flow gas is slight. = -58.8 - (-19.8) = -39.0 e.u., and To establish whether or not a gaseous nitride of A AH = 130 kcal./mole Ga exists, the vaporization of Ga( I) in a helium and in a nitrogen flow system, and the vaporization of Thus, P G ~=N4 X lo-” atm. which is far lower than GaN(s) in a helium and in a nitrogen flow system the observed pressure. Even a sizable decrease were observed. It was found that Ga(1) is vapor- in the heat of vaporization would not make GaN(g) ized to an unexpected extent in a Ns(g) flow and a very important molecule. that GaN(s) vaporizes in either a Nz or He flow a t A possible explanation of the observed vaporiabout the same rate without appreciable suppres- zation involves the formation of a polymer (GaN),. sion by the N2. Weight loss data for GaN vapor- This behavior would be analogous to that found ization are presented in Table I. The weight losses in studies of various gaseous halides where dimeric are reproducible and depend primarily on time and and even trimeric molecules were shown to beaimtemperature with a small dependence on flow rate. portant vapor s p e ~ i e s . ~ The vapor pressures given Flow rates of oxygen-free, dry gases (passed over in Table I1 need only be divided by z to give Mg(C104)zand hot Cu or Ta) mere varied and the P ( G a N ) , . A log P us. 1/T plot of these data gives (1) J . L. Margrave and P. Sthapitanonda, T H l s JOURNAL 69, 1231 a heat of vaporization of 62 5 kcal./mole. (1955). Attempts to obtain an absorption spectrum for (2) R. J. Sime, B.S. Thesis. University of Wisconsin, 1955.
(9)
*
(3) W. C. Johnson. J . 86, 2G51 (1932).
B. Parsons and M. C. Crew, THISJOURNAL,
(4) (a) L. Brewer and N. Lofgren, J . Am. Chem. SOC.,7 2 , 3038 (1950); (b) L. Friedman, J . Chem. Phys., 23, 477 (1955).
