62. 2,4-Dinitrophenol Contributed by WALTER C. MCCRONE AND JOHN KR C, JR., Armour Research Foundation, Illinois Institute of Technology, Chicago 16, Ill. OH I
A-NO:
v1
NO1 Structural Formula for 2,CDinitropbenol XCELLENT crystals of 2,4-dinitrophenol can be obtained by recrystdlisation from alcohol (Figure 1). These crystals are orthorhombic plates or tablets lying on (010)with forms IOkZ) and IhkO). The Miller indices of brachydome and prism vary considerably. However, in general, the simpler forms io11 ) and { 110) are not observed. The forms u s u d y observed are (2301 or {l20), and (0721, 10731, or (031). Figure 2 is an orthographic projection of a tablet with forms (0311and (230). 2,4Dinitrophenol shows pleochroism for views normal to 1010) with yellow parallel to e and very pale yellow parallel to a.
E
A& Bisectrix. a = a. Extinction. Pitrallel and symmetrical. = 1.723. Molecular Refraction (R) (5893 A.; 25" C.). 7R(oalcd.) = 40.2; R(ohsd.) = 43.3. FUSIONDATA. 2,4-DiNtrophenol melts a t 114-115' C. with little decomposition or sublimation. The completely melted
h
CRYSTAL MORPHOLOGY Crystal System. Orthorhombic. Form and Habit. Plates and tablets lying on hrachypinacoid, {OlOl,showing brachydome, {Okll,sndrhomhicprism, (hkOl AxialRatio. a:b:c = 0.2645:1:0.2237. Interfacial AGgles (Polar). 072AOT2 = 76' 6'; 073 A 053 = 55' 8'; 230 A 230 = 43' 16'; 120 A 120 = 55' 46'; 031 A 031 = R79 4'. .. 4 ~~. OPTICAL h O P E R T I E S
Refractive Indices (5893 A.; 25" C.). LI = 1.660 i- 0.002. 0 = 1.738 =t0.003. y = 1.772 zt 0.002. Optic Axial Angles (5893 A,; 25' C,). 2E = 118'. 2V = 66" (calculated from p and 2E); 2V = 66' (oalculated from e,0, and Y ) . Dispersion. I > v. Optic Axial Plane. 010.
Figure 1. Crystals of Z,.i.-Dinitrophenol from Ethyl Alcohol (100X)
C
C
I-
I
I
--a
Figure 2. Orthographic Projection of 2,b-Dinitrophenol Tablet with Brachydome (031) and Rhombic Prism (230)
ANALYTICAL CHEMISTRY
1864
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Polarography. I . M . Koilhof and J . J . Lingane. Volume I. svii 420 pages. Interscience Publishers, 250 Fifth Ave., Sew York 1, N. Y., 1952. Price, $9.00.
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Figure 4. Tablets of 2,4-Dinitrophenol on Meltback Creased Niools, 1W X
~ .~ ~ ” .~ . ~ ~ .~ ~ . A head pattern of fiLeair huhhf& is especially characteris& of these soherulites. On melthaek, 2,4-dinitrophenal gives rods or tablets: The tablets soon grow ahead of-and choke off the growth of the rods (Figure 4). The tablets show a flash figure and t,he rads an ootic axis near the edee of the field of a 0.85 S.A. h s ohserved in these studies ohiective. No ~ b l v m o r ~were X-.RAYD I F F R A ~ T DATA I~N Cell Dimensions. a = 6.11 A,; b = 23.11 A,; c = 5.17 A. Formula Weights per Cell. 4 (4.02 calculated from x-ray data). Formula Weieht. 184.11. Density. 1.&3 ( 1 ) (flotation); 1.675 (x-ray),
Prinoipal Lines I/Il
d
L6 !5
0
in
0.40 1 00 0.10 n 79
d
1/11
0.27 0.12
0.03 3
0.06
ACKNOWLEDGMENT
Most of the work described was performed on a contract between Cornell University and the Office of Scientific Research and Development during June 1943 to July 1944 (a). Alfred T. Blomquist was technical representative of OSRD Section B-2-9 supervising progress of this work. John H. Andreen and SienMoo Tsang were also associated with this project and contributed to the above description. Acknowledgment is due to Irene Carvin, who prepared the powder x-ray diffraction data. LITERATURE CITED
“Chemische Xristallographie.” Vol. 4. Leipsig, Engelmann. 1910.
(1) Groth,
pp. 77, 110-14,
(2) Office of Scientific Research and Development, OSRD Rept. 3014
(declassified).
C o a ~ ~ i s n ~ r of o roiystallographio s data for this seotion should be sent to Walter C. MoCrone. An&lytieal Section, Armour Research Foundation of Illinois Institute of Technology, Chicago 16, Ill.
Since its puhlictLtion in 1941, “Polarography” has been univerd l y recognized as a most authoritative and comprehensivemonograph. “Polarography” described a difficult subject systematically, clearly, and astutely. The second edition, which ha8 been enlarged to the extent that it appears in two volumes, is a. worthy successor. Volume I concerns the theoretical principles underlying the phenomena. occurring at a dropping mercury electrode and other types of concentration polarized electrodes, and also discusses experimental technique and instrumentation. Volume 11, to be reviewed a t a later date, describes applications of polarography to analytical problems encountered in inorganic, organic, and Although somewhat aherea ana rearrangea, m e revmon 01 m i 8 part 01 m e monograph consisted mainly in the addition of critical discussions of the many important advariees made in the last decade (through 1950) in theory and instruments. These additions resulted in a 607’ increase in number of pages. Among the topics that have been added, or given fuller consideration, are the following: polarography in nonaqueous, or only partially aqueous, solvents; adsorption of various substances on the mercury of a dropping electrode and the resulting effect on current-voltage curves; palarogrephic waves that are influenced by reaction rates, including ‘katalyzed waved’; unusual diffusion current phenomena such as interfering electrode reactions, compensating anodic and cathodic currents, and the “water current”; special types of dropping, streaming, and stationary electrodes; oscillographic, derivative, and differential polarography; new designs of polarographs and polarographic cells; separations that can he made preliminary t o polarographic analysis; experimental factors of partieulas interest and aid to beginners. This excellent treatise is invaluable to anyone interested in polarography. T . S. LEE X-Ray CrystallographicTechnology. Andrd Cuiniev. Translated by T. L. Tippell and edited by Kathleen Lonsdale. xiv 330 pages. Hilger and Watts, Ltd., London, England, 1952. Price, $9.50.
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This book is an English translation of Guinier’s ‘LRadioeristallographie” which appeared in a French edition in 1945. This alone recommends it to new readers, since only an outstanding hook warrants the labor and cost of publishing a translation. Diffraction workers throughout the world acclaimed the original volume, because of its lucid treatment of the technical applications of x-ray diffraction, including many which a t the time were not widely used or understood. An English edition, therefore, cannot help hut bring this same material to B far wider audience. The reviewer has read i t with the French version handy for frequent oomparisons, and can say that it is a faithful translation. It was noted that a few errors have crept into the new volume, hut these are judged to he almost without exception trivial, and not likely ta give the reader trouble or inconvenience. The reprinting has also given the opportunity to correct several minor crrors that appeared in the original. A few additions and changes have been made, hut these are by no means extensive enough to warrant the book’s purchase for them alone. The book, however, is enthusiastically recommended
