ANALYTICAL CHEMISTRY
620
When t = 0, ra = F, X (R,/RA
Using as a measure of response the time required for half of the correction to take place, we find t , , ~ = 0.432 minute. An experimental test run with the same constants gave k l z = 0.584 mnnte, 35% longer. This is attributed to fluid friction hindering the liquid transfer. CONSTRUCTIONAL DETAILS (FIGURE3)
--L
~xponentiallye
m =
A , B, C, D, and G are of 9-mm. tubing N is of IO-mm. and M is of 28-mm. tubing. L is a standard kliter bottle &de diameter 150 mm.). K is B reservoir of regulator liquid, so that the flow rate may he set to the required value. PP axe 14/35 joints and Q is a 35/45 joint. J is a safety manometer preventing the liquid from rising through M and out C io cases of extreme hack pressure. J may also he used to indicate the back pressure ahove atmospheric.
R (+) R,-R
EI ( F ,
- F~)
OTIIER USES
F2 = F, - F,
YG)
The regulator may :dso he used from the low pressure side of a system t o provide 'constant pressure at point in a system, regardless of flow resistance hetween the point and the regulator.
- 1
em*
In this service G is connected to tho point to be held constant,
ml. ml. For example, let F, = 78 -; ; 396 : nun. A M =
RI
36 mm. = *_a..,
below atmospheric).. A tendency for' the dresswe to increase
Let the resistance he suddenly changed
( H I )(detkrmiied by J). -1
Then R = 78 - 78 X 59 - 36 59
e
x m
78
Because the apparatus is made entirely of glass, nearly all corrosive gases may be handled with a proper choice of regulator liquid-e.g., for chlorine the liquid may be sulfuric acid.
g
~
Fa = 78 - 30.4 e -
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=".ul.
3.341 min.
pi."*-
RECEIVED February 24. 1850
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29. Antabuse (Tetraethlyl Thiuram Disulfide) . . . ... . . Contributed by D. G. GRARAR AND W. C. MCCRONE, Armour Kesearch Foundation, Illinois Institute nt Technology, Chicago 16, Ill.
RESTATEMENT of the objectives of this crystal series A seem desirablk a t this time. The project was fmt under-
taken because optical crystallography is neglected as 1u1 analyticel tool because too few compounds have been described. An analyst now may determine the optical properties of an unknown material, hut there is little chance of finding those propertics tabulitted so that 6he compound can be identified. We hope hy publication in ANALYTICAL CHEMISTRY to initiate process which will enahle a group of crystallographers to complete the tabulation of crystal data for most of the common everyday compounds. This would make optical crystallography a useful analytical technique, justify its study in the academic curriculum, and produce more crystallographers further t o speed the process of accumulating data. We realize that this is the first step i n a very long program and that a great deal of help will he required. Crystallogmphers can help by submitting data for inclusion in this program. Most crystallographers, however, apparently feel that only complete data will he accepted for a given compound. One of the principal purposes of this statement is t o correct this impression; quite incomplete and even fragmentary data will be gladly accepted. We would like to receive any part of the following:
1. Solubility data on the compound with information as to best solvents for goad orystals. 2. Any information on hydrates or other solvates, polymorphs, decomposition, etc. 3. Goniometrio data (complete or incomplete).
A
Figure 1. Antahuse A . Grown from melt B.
Grown from a thymol I
V O L U M E 22, NO. 4, A P R I L 1 9 5 0 for single crystal x-ray work (about 0.1 to 0.5 mm. in longest dimension). The size of the sample desired depends on avail:ibility of the compound (1 mg. of B I up ~ to not more than 2.5 p n m s of the more common compounds). The emphasis throughout this project is, of course, on data f i x the common and important compounds. Data for unusual, uncoinmon, or rare compounds will not be complet,ed or published, at least at this time. All data submitted will, however, I w added to a general crystal file which already contains many unpublished data. This file is n o x being completed with respect I O the published literature on opt,ical and x-ray data. We would like very much to ext,end the coverage of this file t,o include even unpublished data, so that it would furnish as complete as Imssihlc a source of crystallographic, data. We are already in a pwition to invite inquiry from nii\-one desiring such information :iiid hope gradually t,oimprove the i*ovc.ruyeoffered. Finally, publication of earh monthly desrript.ion is now recognized by crediting the contributor with authorship. Each puhliration is so noted in A~VALYTICAL CHEMISTRY and is indexed by author and title in the abstract, journals If a deswiption is published in which this laboratory had only t,he job of minor checking, photomicrographs, crystal drawing, and fusion data, the outside contribut,or will be listed as sole author. If, however, it is necessary to complete the fundamental data, x-ray, optical, etc., a junior author from the foundation will be :tdded. If a minor part of the data was submitted and our laboratory has to do a major part of the determinative work, a major author from the foundation will be named. In every case, we will try t o be very fair, even to the ext'ent of sacrificing our position in cases of doubt. The procedure for each compound will, in every case, be as follows: I . Literature search. 2. ('hecking of data submitted. (This does not neressarilv inem repeatingwork; a, b, and c could be checked against go&metric data and by the relationship between density, molecular weight, number of molecules per cell, and cell volume. If all these data were consistent, the cell dimensions would be accepted. 3. Completion of data to include crystallization, goniometric, optical, x-ray, and fusion data. 4. Photomicrography, crystal drawing, and writing up of d:lt:t ill standard form for publication in .~SALYTICAL CHEmSTRY.
621 Interfacial Angles (Pol9r). 011 A 611 = 47.5". Profile Angle. 01: A 011 in 100 plane = 123". BetaAngle. 126 . X-RAYDIFFR.4CTION DATA Cell Dimensions. a = 13.84 A , ; b = 15.90 A.; c Formula Weights per Cell. 4. Formula Weight. 296.52. Density. 1.292 (pycnometer); 1.302 (x-ray).
=
8.66 A.
Principal Lines d 9.11 7.97 7.58 6.38 6.09 5.63 5.29 5.09 4.76 4.64 4.31 4.16 4.07 3.94 3.77 3.60 3.45 3.38 3.34 3.25 3.17
IiIl 0.16 Very weak 0.40 1.00 0.38 0.18 Very weak 0.40 0.07 0.26 0.12 0.69 Very weak 0.13 0.09 0.33 0.20 0.19 Very weak 0.08 0.28
d
3.07 2.98 2.91 2.82 2.77 2.70 2.64 2.60 2.52 2.47 2.43 2.38 2.33 2.28 2.25 2.22 2.19 2.15 1.87 1.71
I/[, 0.05 0.13 0.11 Very weak 0.09 0.04 0.04 Very weak 0.16 0.13 0.09 Very weak Very weak 0.07 0.06 0.13 Very weak 0.09 0.10 0.11
OPTICALPROPERTIES Refractive Indexes (5893 A.; 25' C'.). 01 = 1.590 * 0.005; 6 = 1.67 f 0.01; y = 1.740 * 0.005. Optic Axial Angle (5893 A.; 25' (2.). 2V = 84" * 5 " . Dispersion. v> T Optic Axial Plane. 010. Sign of Double Refraction. K'egative. Acute Bisectrix. BX.Aa = 3" in obtuse 6. Extinction. yAc = 33' in obtuse p. Molecular Refraction ( R ) (5893 A , ; 25" C.). 1.67. R (calcd.) = 84.2. R (obsd.) = 85.0. e
3 -
da6y =
C
I
Tlie foundation sincerely hopes that thib project can develop informaf ion of great usefulness to the analytical chemist and to those starting out on structure determinations on one of the compounds that happens to have been covered. Comments, criticisms, or suggestions on any phn\e of this program will be greatly appreciated. CRYSTALLOGRAPHIC DATA FOR ANT4BUSE
.htabuse is the drug recently discovered to be of value in the treatment of alcoholism. It is extremely soluble in most organic solvents and good cryst~lscan be obtained from ethyl alcohol, benzene, and dioxane. So pcilymoiyhism was observed during this study. S
\
S
Figure 2. Orthographic Projection of Typical Crystal of Antabuse
Structural formula of antabuse CRYSTAL MORPHOLOGY Crystal S stem. Monoclinic. Form and 6 a b i t . Crystallizes from ethyl alcohol in needles elongated parallel to c, and in tablets lying on 010 showing clinopinacoid ( O l O ) , orthopinacoid { 1001, and clinodome (0111. A variety of other dome, prism, and bipyramid forms usually also appears. The simple form show in Figure 2 is obtained hy iecrystallization from thymol on a microscope slide. Axial Ratio. a : b: c = 0.870: 1: 0.545.
FC'SION DATA Antabuse melts at 69-70 C. without sublimation or deconiposition. The melt supercools and crystallization usually must be initiated by seeding. The crystals grow rapidly parallel to c and the crystal front in a thymol mixed fusion shows characteristic well-shaped rhombs lying on pinacoid or dome faces. Some crystals may show the characteristic optic axis interference figure.
It is a pleasure to acknowledge the assistance of Irene Corvin and Anne Humphreys in obtaining the powder diffraction data.
