OFTLGAL PROPERTIES Refractive Indices (5893 A,. 25" C.1.
a =
1.450. 8 = 1.680,
limation but no decomposition. The sublimate is well formed (Fipure 1) and shows d a t e s lying on 010 with (110), 11011,
, ,.
Dispersion. Strong, r > u. Optic Axial Plane. 010. Acute Bisectrix. a. Extinction. a A a = 39' 15' in ohtuse 8. FU~ION B ~ n a m o a . Isovanillin melts a t 114-5" C. with sub-
LITERATURE CITED
(1) Mecrone, IV. C.. ANAL.C n m 22, ~ 500 (1950).
104. D-fructose 2,4-Dinitrophenylhydrazone Dioxane Solvate FRANCIS T. JONES, D A L E R. BLACK, and LAWRENCE M. \xlHlTE Wertern Utilization Research Branch, Agricultural Research Service,, U. 5. Department of Agriculture, Albany 10, Calif.
r THE
preparation of D-fructose 2,4-dinitrophenylhydrasone
1 dioxane solvate (CaHt6N4Op.C,HsOe)hits been described by
White and Seeor ( 1 , 8 ) . Their yellow crystalline preparations were used in this study. Fresh preparations were used in order to avoid a surface film of decomposed material. Fresh surfaces obtained by fracturing the cryntals could be used for refractive index determinations. The tips appeared different from the blade in some cases.
Form and Habit. Loose clusters of slender blades or noedles tapering to shows crys elongation Fi re 2 &I 'e inconspicuous. T d n n i n g 'was n o t observed gterfaci al Angles. No angles could be measured, although the cross sectiasn shown in Figure 2 is approximately correct. X-RAYDIE 'FRACTION DATA Space Group. Probably D: - P2,2,2,, but possibly 0: P 2 M , sin ce only the first four orders of 001 observed. Also observed fi rst 14 orders of h00 and first 10 orders of OkO. Cell Dimiensmns. a = 20.669 A., b = 20.788 A,, c = 4.788 A. Axial Ratio. a:b:c = 0.9943:1:0.2303. Formula Weights per Unit Cell. 4(4.061 calculated). Formula Weight. 448.38. Density. 1.4693 grams per cc. (density gradient tube). ~~
~~~
~~~~
~
~
~
~
~
~
~
OFTICAL PROPERTIES Refractive Indices (5893 4.;2 i " '2.). a = 1.593 i 0.001. = 1.872 i 0.004. B = 1.607 A 0.002. Optic Axial Angles (5893 A,; 27' C.). 2E = 42 4z 2'; 2V = 26' calculated from 2E and 8 ; 2V = 29' calculated from a@-,.
-,
>b' " i :"< Y=1.872 C I
Figure
1. D-Fructose 2,4-dinitmphenylhydrazone dioxane solvate (ZW X)
-4 crystal mounted on a goniometer head was used for x-ray diffraction. The same mounted crystal was used for the observatioo of the relstionship between crystallographic axe8 and optical properties. I n spite of many attempts t o grow large crystals, the crystal faces were always too small to give observable reflections on the optical goniometer.
CRYSTAL MORPHOLOGY Crystal System. Orthorhombic, Class 6 bisphenoidal, enantiomorphic.
Figure 2. O r t h o g r a p h i c projection of typical crystal of f r u c t o s e 2,4-dinitrophenylhydrazone dioxane solvate
V O L U M E 28, NO. 2, F E B R U A R Y 1 9 5 6
269
X-Ray Powder Diffraction Data
-
( T h e camera radius was 7.181 cm. X for C u K a 1.5418 A . and a nickel filter was uscd. T h e relative intensities were visually determined with a calibrated intensity scale) d 14.66 10.38 i.31 A 54 5 73 3.21 5 03 4 88 4 67 4 54 4.86 4.25
1,’Il
d
I/Ii
0 09 035 0 06 0.10 0.18
4 14
0.08 0.20 0.07 1.00 0.30 0.10 0.20 0.08 0.02 0.25 0.11 0.11
0.04
0 04 0 23 0 20 0.20 0.20 0 3.5
4.04 3.94 3.87 3.68 X55 3.46 3.33 3.23 3.14 3.08 2.997
d 2.924 2.849 2.779 2.fi87 2.589
2.506 2.447 2.370 2.320 2.261 2.163 2.070
1/11
d
I/Ii
0.05 0.09 0.09 0.08 0.06 0.06 0.02 0.04 0.02 0.08 O.0fi 0.06
2.030 1.988 1.956 1.919 1.862 1.795 1.729 1.695 1.659 1.617 1.572
0.02 0.02 0.02 0.01 0.02 0.02 0.01 0.01 0.01 0.01 0.01
Acute Bisectrix. y . Pleochroism. Slight, y orange yellon-, N greenish yelluw. FVSION.When crystals on a slide are n-armed to ahout. 150’ C. they become opaque and orange in color. Continued heating with a cautery needle held close to t’he cover glass c a w ’ s t’he c r y ~ t ~ a to l s melt with slight bubbling t o an amber liquid. Overheating will cause darkening. If the nielt is kept warm, unmelted crystal fragments will seed regrowth of hairs ant1 needles, Unseeded drops of warm melt will develop “isotropic” spherulites which resemble the “gel” reported by White and Secor ( 2 ) . These spherulites appear predominantly around the margins of the melt. LITERATURE CITED
(1) White, L. AI., and S e m r , G . E., .%SAL. C m x . 27, l O l G (19551, ( 2 ) White, L. 11..and Secor. G . E.. J . .4m.Chen?.SOC.75, 6313 (1953).
1)ispersion. ( v > T ) strong. Optical Character. (+). Optic .ksial Plane. (010). Fragments usually lie on (010) and shorn an optic normal interference figure.
COSTRIBLITIONS of crystallogragliic d a t a for this section should be s p n t tu Walter C. RIcCrone, Analytical Research, Armour Research Foundation of Illinois Institute of Technology, Chicago 16, Ill.
SCIENTIFIC C O M M U N I C A T I O N
Analysis of Phosphorus Compounds Use of Nuclear Magnetic Resonance Spectra in Differential Determination of the Oxyacids of Phosphorus TUDIES
;ire now under way on developing the nuclear magnetic
S resonance technique ( 3 ) as a qualitative and quantitative analyticid tool in phosphorus chemistry. Suclear magnetic resonance is a rapid and elegant method for carrjing out chemical analyses; and, as this work on mixed osyacids of phosphorus demonstrates, the nuclear magnetic resonance method offers a fresh approach t o analytical problems for which wet-chemical prowdures have not been satisfactory. This technique is unique as an analytical tool, in that there can be no interference from compounds of any element other than the one under study, as long as the substances being studied are not precipitated from solut i on. It has been pointed out (6) that isolated PO, ions, end PO4 g r o u p , and middle PO, groups in the phosphates (,$, 5 , 8) give definite, resolved resonance peaks. This means that all mixtures of orthophosphates, chains, and rings ( 7 ) can be characterized in terms of the relative number of moles of phosphorus pentoside present as orthophosphates, end groups, and middle groiips (4). Suclear magnetic resonance can be used equally well t o identify anions of the phosphorus oxyacids of lower oxidation etates. Three resonance peaks are found for hypophosphite, trvo for ortho- or pyrophosphite (which cannot be differentiated by this method), and one for hypophosphate, in accordance with their structures ( 1 , 4). In Table I, the anions of the various oxyacids of phosphorus are listed in the order of t,heir chemical shift. The intensity factor shown indicates the relative area (and t o a rough approsimation, the height) of the resonance peak for equal numbers of phosphorus atoms. Thus, a t equal molar concentrations the hypophosphite peak a t 133 p.p.m. shift is only one quarter of the area of the orthophosphate peak with a shift of 100 p.p.m. under the same experimental conditions. (Practical measurements are conveniently made with respect to orthophosphoric acid, and this compound is therefore used as a reference for a il40-gauss field. -4value of +lo0 p.p.m. is arbitrarily added t o tlie shifts
measured with respect to orthophosphoric acid in order to convert all shifts to positive values. The chemical shifts between the various oxyacids of phosphorus are precise t o ea. =k2 p,p.m. and can be made still more precise if the need arises.) Even thoiiph
Table I. Nuclear 3Iagnetic Resonance Peaks for Oxyacids of Phosphorus
-4nion
Chemical Shifta, P.P.M. e P.P.31.
*
Relative Intensity 1
Bcillea, P.P.M.
0.5
0
7 140
Hypophosphite
133
Phosphate middle groups and ortho- and pyrophosphites Phosphate end groups Orthophosphate
120
120h
109 100
100
Hypophosphate Hypophosphite
$11
Ortho- and pyrophosphites
64
Hypophosphite
42
87
40
a Measured in p.p.m. of a 7140-pai1.;~ field witti a limb? rrsonating a t 12.3 mc. Reference substance from which the shifts are ineasiired is 85% orthophosphoric acid. T h e position of the orthophosphoric acid reference standard was arbitrarily defined as A100 on the p.p.m. scale of chemical shifts. Other chemical shifts are then defined by the relation 6 = 100 10‘ X ( I I H H S P O I,”HPPO~. ) b Phosphate middles shown as black b a r and phosphite? as cross-hatched bar.
+
