CRYSTALLOGRAPHIC D A T A
85. 1,&Dinitronaphthalene Contributed by WALTER C. M K R O N E , Armour Research Founaetton ot Illinois Institute of Technology, Chicago 16, Ill., And J O H N H. ANDREEN, E. I. du Pont de Nemoun & Co., Inc., Wilmington, Dol. NO,
Axial Ratio. a:b:c = 0.482:1:0.227. I n t e ~ ~ c i $ A n g l e s ( P o l ~ ~l )l O . A i l 0 = 130"8'. 011 A O l i =
fKz.0 , d l
Beta Angle. 105.5'. DIFFRACTION DAT.4 CellDimensions. a = 7.85A.; b = 16.26A.; c = 3.70A. Formula Weights per Cell. 2 (2.004 calculated from x-ray iata). Formula Weight. 218.16 (218.6 calculatedfromx-ray data). Density. 1.595 (flotation in CHsh and benzene); 1.592 x-ray).
X-RAY
I
NO, Structural Formula far 1,5-Dhitronaphthalene (1,S-D")
C
RYSTALS of 1,5-dinitrans,phthalene from d l ordinary solvents are monoclinic rods elongated parallel to e. Sublimed crystals are usually flattened 010 plates (Figure 1). There is no evidence of polymorphism for this compound.
CRYSTAL MORPHOWQT Crystal System. Monoclinic. Form and Habit. Tablets lying on the clinapinacoid {OlO) showing the clinadome { O l l ) , prism { IlOJ, and occasionally the basal pinacoid {OOl).
Principal Lines I/Il 9
d 8.12 7.60 6.87 5.53 4.40 4.24 4.06 3.79 3.69 3.60 3.47 3.25 3.10 2.98 2.88 2.75 9
1
9
9 1 1
8 2 7 9
9 10 1
7
2 3
3
69 64 57
I I
47 40
I I
b
,
,
ninitronaphtha-
d
I .~ /I.
2.36 2.28 2.22 2.18 2.14 2.06 2.02 1.994
a
1.959
1.920 1.877 1.841 1.794 1.767 1.718 1.684 1.628 1.564 1.?19 ' 16 :8
1
a 3 1
6 2 2
3 1 2 2 3 3 2 1 1
2 2 2
- --
Figure 3. Orthographic Projection of a. Typical Crystal of 1,5-Dinitronaphthalene
lene from M t.1. .f
1390
1
1
1391
V O L U M E 26, NO. 8, A U G U S T 1 9 5 4 Or~~rcar, PROPERTIZS Itefract,ive Indices. [58W .\.; 25' C'.). O( = 1.513 =k 0.002. $ = 1.755 =k 0.005. y = 1.817 3= 0.005. Optic .kxial Angles (5893 a,; 25" C'.). 2H0= (-)56". 2V = ( - )48" (cplculated from p and 2H); 2 E = !I0 . 1)ispersion. T > v, strong. Optic Axial Plane. 010. Kxtinction. 01 A c = 13' i n oI)tusts 3 . 11olecular Refraction ( R ) [589:3 -1;;-25' C.!,). gas = 1.890. R(ca1cd.) = 54.1; R(obsd.) = 03.1. F C ~ I OD'4TA. N l,5-dinitronaphthalene sublime:: easily in the Kofler block t o give characteristic plates lying on the clinopinacoid (Figure 1). On further heating, melting occurs a t 216-217" C. The melt does not supercool more than a few degyres and crystallization is very rapid. Using oil immersion, many crystals grown from the melt show opt'ic axis and even H 4 n figures with 2H = ( -)56", r > z' strong [Figure 2). ACKNOWLEDGMENT
.\lucli of the work described :hove was performed untlei, :I contract between Cornel1 University arid the Office of Scientific Herearch and Development during World War 11. Alfred T. Uloniquist was technical represent3 tive of OSRD Section R-2-.1 supervising progress of this work. CONTRIBWIONSof crystallographic data f u r this section should be sent t u Walter C. MoCrone, Analytical Section, Arnioiir Research Foundation of I!linois Institlite of Technology, Chicago 16, Ill.
MEETING REPORT
Society for Applied Spectroscopy HE Society for Bpplied Spectroscopy held its ninth annual meeting in New Pork, M a y 27 and 28. I n addition t o ail exhibit of spectroscopic instruments, a group of papers on the theme of "Frontiers in Spectroscopy" n-as presented. Isotope Analysis by Emission Spectroscopy. J . R. McN.\I.LY,JR., Oak Ridge National Laboratory, Oak Ridge, Tenn. This pager covers applications of high resolution spectroscopy t o t h e determination of i3otropic concentrations in materials. Material was presented on the source and instrumental problems associated with this field of analy and illustrations were given of the preci-;ion ohtainable and t h e future potentialit,ies in this field. An R F Linear Decelerator Spectrometer. WALTDOXNER. Mass Spectrometry Research, Beckmsn Instruments, Inc., Fullerton, Calif. - i n R F linear decelerator mass spectrometer was described, featuring resolution to 100 and a dynamic range of 2000 t o 1. Ions are formed by electron impact in a somewhat conventional ion chamber, utilizing a n electron beam a t right angles t o t h e ion beam, temperature regulation, and pressure differential for high signal t o background ratio. All of t h e ions are then accelerated through 2500 volts, collimated, and then passed through a series of 34 RF gaps, spaced such t h a t t h e preferred (or resonant) particles are decelerated hy a n amount equal to t h e peak R F voltage a t each gap. all other particles emitting from t h e R F analyzer with correspondingly higher energies. T h e resultant "energy dispersed" beam is then separatrd in a n electrostatic deflection system, t h e preferred (lowest energy) beam being collected in a Faraday bucket, and observed on a vibrating reed electrometer. -4linear mass scan is achieved by varying t h e frequency applied t o t h e gaps. Typical mass spectra and stability figures were given. Reflection of Infrared Radiation from Free Liquid Surfaces.
E.
D. MCALISTER, Eastman Kodak Co., Rochester, N. Y. Simple modifications of a conimercially available douhle-beam spectrophotometer employing a sodium chloride prism provide full scale readings for 5 or 10% reflection with signal t o noise ratios of about 100 t o 1. This expedient enables detailed study of the anomalies in reflectivity corresponding to regicns of high absorption Coefficient even though t h e reflectivity is only 1 or 2%. T h e possibility of measuring t h e absorption coefficient (when large enough t o cause a n appreciable anomaly in reflection) by measuring the reflectivity for two different angles of incidence was discussed. Some suggestions concerning t h e nature of surface layers of molecules
and of surface contaminat,ions given by these studies were discussed. Typical spectrograms were shown. Sensitivity of Detection of Deuterium Oxide by Infrared Absorption Spectroscopy. W. A . PATTERSON. This paper describes some preliminary experiments on the detection of heavy water in ordinary water, using t h e Baird Associates infrared spectrophotometer. Using 0.5-mm. calcium fluoride cells, t h e differential method of infrared analysis. a reversed cell technique, and nTide fixed slits, deuterium a s a n additive in water can be readily detected in percentages Under presaslow as 0.01% with a probable precision of i O . O O l % . e n t conditions a n ultimate sensitivity of 0.003% deuterium oxide seems probable. T h e determination of ultimate sensitivity has been restricted by bad scattered light conditions when spectrophotometric* slits are widened. If this scattered light problem can be solved, a n ultimate sensitivity of 0.001% deuterium oxide does not seem out of t h e way. Importance of Collision Process in Spectrochemical Analysis. LESTERW. STROCK, Sylvania Electric Products, Inc., Bayside, L. I., N. Y. T h e departure of calibration curve slopes from unity has been interpreted a s due to excitation energy exchange on collisions between atoms in different states of excitation. T h e extent t o which t h e Ijhenomenon affects spectrochemical results was illustrated by typical hut actual calibration curves based on synthetic silicate standards. T h e critical role of a varying sample matrix was pointed o u t . . i n a t t e m p t was made t o account for t h e effect of t h e collision process in t h e intensity equation.
New Multichannel Direct-Reading Spectrograph. FREDERICK BRECH,FRED4. AICNALLY, AND LORENP. NEAL,Jarrell-Ash Research Laboratory. A multichannel direct-reading spectrograph based on t h e Wadsworth mount was described. Spectra are displayed on two levels on each of which several fixed position exit slits and photomultipliers may be located. B y this arrangement, two det,ector tubes m a y be sited on two lines with a small wave-length separation without t h e use of optical separator elements. With t h e circuits employed, t h e signal from each photomultiplier is converted t o fixed amplitude pulses whose frequency is proportional t o the signal strength. T h e working curve for each channel is displayed on a separate dial face t h e rotation of which from a fiduciary position may be employed when necessary to compensate for a shift of the working curve. Details of t h e instrument and samp!e analyses performed with it were discussed. Raman Spectrometer Assembled from Available Components.
S. M. DAVIS,R . F. STAMM, G. L. ROYER,AND H. C. LAWRENCE. American Cyanamid Co., Round Brook, N. J. A photoelectric Raman recording spectrometer has been assembled from commercially available optical and electrical components. T h e light source is a Toronto-type mercury arc supplied by hpplied Research Laboratories. T h e arc controls and housing were built in our shop. T h e sample tubes, filter jarket, and condensing lens system h a r e been deicribed by one of t h e authors. T h e monochromator started with a Perkin-Elmer Model 12 spertrometer equipped with a 60' light flint glaw prism and off-axis parabola. T h e standard Littrow mirror was replaced by a plane diffraction grating nThose dispersion aiirments t!iat of the pri.cm. T h e slits were modified t o correct f o r the cauri-ature caused by the prism. An RCA 1-P-21 photomultiplier was mounted inside t h e monochromator directly behind t h e exit slits. T h e standard Perkin-Elmer 13-cycle chopper and Model 81 amplifier modified t o have 1-, 2-, 5-, and 12second time constantswere used. T h e output from this is recorded on a standard L & N Speedomax rrcorder whirh had been modified with an automatic range changing device supplied by Karren Electronics. Some performance data were giren. Progress of the X-Ray Spectrograph. . BEHR,North American Philips Co., Inc. T h e advent of t h e x-ray spectrograph into the analytical field is not new. T h e method -cas thoroughly studied and widely applied a generation ago. However, t h e inatrument has been commercially available for only a few years. Research and commercial control have found t h e method useful and its acceptance has been rapid. Several hundred units are in use a t t h e present time and there is a rapidly growing wealth of information available touching on such factors a s fields of applicability, techniques, and analyses of d a t a . These points were summarized. T h e future progress of t h e method can be predicted in t h e light of t h e past progress, t h e inherent features, and t h e known lines of instrumentation changes in design and contemplation. There are certain limitations imposed by t h e basic physics involved, and t h e practical limits t h a t these impose are becoming evident.
