ANALYTICAL CHEMISTRY
320 Table I. Determination of Absorption Ratios' for Duplicate Hydrolyzates*of Waxy Maize Starch and Crystalline Swine Pancreatic Amylase Time of Hydrolysis, Minutes 0 10 20 30 40 50
Absorption Ratiob 1.00 1.00 0.932 0.945 0.803 0.786 0.689 0.675 0.572 0.591 0.500 0.493
Deviation from Mean, d e d X 105 6.5 8.5 7 0 9.5 3.5
adapted for a study of the inhibiting effects of these low molecular weight products on the initial velocity of the hydrolysis of branched components of starches by a-amylases. ACKNOWLEDGX EYT
The authors wish to thank the Corn Industries Research Foundation for generous grants in aid of this investigation. LITERATURE CITED
Baldwin, R. R., Bear, R. S., Rundle, R. E., J . Am. Chem. SOC.
where ODt = absorbance of hydrolyzate a t 540 mu and 540 mu. b Wa& maize starch 0.00625%, 0.02.W NaCl. 0.01M phosphate; p H 7.2. C Standard deviation = 10.007 A R unit.
a AR = Y at time t OD0
66, 1 1 1 (1944).
z t Y Y
Bates, F. L., French, D.. Rundle, R. E., Ibid., 65, 142 (1943). Beckmann, C. O., Roger, 31.,J . Bid. Chem. 190,467 (1951). Caldwell, 32. L., .4dams, Mildred, Kung, J. T., Toralballa, G. C., J . A m . Chem. Soc. 74, 4033 (1952). Caldwell, M. L., Doebbeling, S. E., Manian, 5. H., ISD. ENG. CHEX, ANAL.ED. 8, 181 (1936). Hanes, C . S., Cattle, 31.,Proc. Roll. SOC.( L o n d o n ) B125, 387
= absorbance of original waxy maize starch solution a t
0.0625 gram of defatted (9, 12) waxy maize starch per liter. T h e data summarized in Table I show that the standard deviation for a single determination is f0.007 A R units. From the relationship given above, this value would be equivalent to a standard deviation of 1 0 . 0 9 % theoretical glucose or 1 3 . 5 X 10-7 mole of aldehyde groups per liter. Limits of Concentration of Waxy Maize Starch. The lowest concentration of waxy maize starch that can be subjected conveniently to this technique is 0.0062570. It should be possible to study still lower concentrations by wing a cuvette with a longer optical path. The upper limit of substrate concentration is fixed only by its solubility. Inhibition Studies. Because iodine does not produce colored complexes with the l o m r molecular weight products of amylase action, the spectrophotometric method reported here can be
(1933). \ - - - - ,
Kung, J. T., Hanrahan, V. 3T.,Caldwell, 31.L., J . A m . Chem. SOC.75, 5548 (1953) McCready, R. AI.. Hassid. W.Z., Ibid., 65, 1154 (1943). Mindell, F. hI., Agnew, -4. L., Caldwell, 31. L., Ibid., 71, 1779 (1949).
Phillips, L. L.. Caldwell. 31. L., Ibid., 73, 3863 (1951). Rundle, K. E , Foster, J. F., Baldwin, R. R., Ibid., 66,
2116
(1944).
Schoch, T. J., Ibid., 64, 2954 (1942). Swanson, M. A., J . Bid. Chem. 172,805, 825 (1948). Van Dyk, J. W., dissertation, Columbia University, Yew York. 1984. RECErVLO for review Aiigiist 5 , 1955 Accepted December 14, 1955. Data taken from a dissertation submitted by John W. Van D y k in partial fulfillment of requirements for degree of doctor of philosophy in chemistry under the Faculty of Pure Science of Columbia Vniversity.
Activation Analysis of Trace Impurities in Germanium Using Scintillation Spectrometry GEORGE H. MORRISON and JAMES F. COSGROVE Chemistry Laboratory, Sylvania Electric Products, Inc., flushing,
A method has been developed, based on the use of neutron activation analysis, for the quantitative determination of trace impurities in germanium. Gamma scintillation spectrometry has been employed to identify and measure the amounts of the various impurities present. The method employs a minimum of chemical separation. A sensitivity of 0.001 to 1 y is attained for most elements using this technique.
THF.
, e ectrical properties of semiconductors, and the characteristics of devices in which they are used, are profoundly influenced by the presence of trace impurity atoms. I n the case of germanium used in transistors, the concentrations of impurities are so minute that previously available methods of detection have proved ineffective. Seutron activation analysis in conjunction with gamma scintillation spectrometry has been applied successfully t o the analysis of trace impurities in silicon (e), and the present study concerns the development of a similar method for the analysis of trace impurities in germanium and some of its compounds. While methods using activation analysis have been developed in the past for the determination of traces of arsenic ( 4 ) and copper (6) in germanium, the present study takes advantage of the resolution
N. Y.
of the gamma scintillation spectrometer, which permits the identification and measurement of many impurities in the same analysis with a minimum of chemical separation. The method possesses a sensitivity of 0.001 to l y for the majority of the elements. NUCLE4R REACTIOYS
When a sample is irradiated with thermal neutrons in a pile, many elements undergo an ( n , y ) reaction n-ith the formation of the corresponding radioisotopes. The amount of the radioisotope produced is proportional to the flux of neutrons involved, the reaction cross section, the neight of the element being investigated, and the duration of the irradiation. It is possible for other nuclear reactions such as (n,p)and (n,.) to occur in the case of a few elements, but it is accepted that the ( n , y ) reaction will predominate when a sample is irradiated in a pile. When germanium is irradiated, the ( n , ~reactions ) summarized in Table I occur. Three radioisotopes of germanium-germanium$1, germanium-75, and germanium-ii-are formed, as well as radioactive arsenic-77-a product of the decay of germanium-ii. Similarly, radioisotopes are formed from impurities present in the sample. hlany of the nuclides formed from the impurities are gamma emitters. Consequently, gamma scintillation spectrometry is used t o identify these impurities; it is based on the characteristic energies of the gamma photonsof the respectivenuclides.
V O L U M E 28, NO. 3, M A R C H 1 9 5 6 ~~~~
~
~
~~~~
321 ...
~~
.
.
~~~
for a 3-day irradiat,ion: many of the isotope. approach saturation in this interval of time. The majority of these elements prodlice one or more Isotopic Natiirally OccLirririg .$bunCross 3Iethod radionuclides which emit g:Lmma photons identiStahlr dance, Section, Isotope Half of Isotope fiable by the differences in the energies of these 1POtOlJt.i % Barn Formed Life Decay Formed photons with the gamma scintillation spectrom(icriiianiuri>-;O 20.6 3 .3 Germaniuni-71 1 1 . 4 days R Galliam-71 eter. Liquid germaniinn tetrachloride samples (stahl:)? sealed in quartz ampoules were irradiated in the ( i ~ r i i ~ a n i i i i i > - i 43 6 . 7 0.2 Ger~nsniuni-7.5 45 see. p - , -, .Iracnic-t.l 0 3 8%min. (stah!? water-cooled facility of the pile a t approximately iiinniiiiii-i+j 7.7 0 Oli C ; e r ~ n a n i i i n ~ - i i58 SCC. ? - , 7 Arsenic-77 room temperature. 0,3O 1%hours (radioactive) Chemical Separations. Germanium, the major element, when irradiated under the above condi. tions, results in nuclides that emit gamma photons; therefore, it was necessary to separate c~hemicdly the radioactive germanium from the radioactive Intd'ei~c.nce in the impuritl- analysis occurs as a result of impurities s3 that the impurities could be measured with the rcwntlnry jn,-,) reactions during irr:tdintion of germanium. gamma scintillation spectrometer. The distillation procedure St:il)le gnllium and arsenic, formed I)>- the decay of germanium, employed was a modification of that used by Smales and Pate ( 4 ) . g i w rise to radioactive gallium-72 and arsenic-76, which are 13ec:iiise of the relatively high activity of the irradiated germasome lead shielding of the distillation apparatua inctistingui~h:~1~1e from gallium-72 and arsenic-76 formed from the corrcqonding impurity originally present in the sample. The rcrmaniuni samplcs after irrndint ion w c e crushed :irtions for their formation are: ith 50 ml. of aqua regia in a 100-ml. distilling flask. Irradiated germanium dioxide samples \Tere dissolved in a distilling flask using 50 nil. of concentrated hydrochloric acid cont:iinirig 1 ml. of concentrated nitric arid. Preparation of irradiated gernianiiini tetrachloride samples for distillation was a complished by adding it drop by drop to 10 tilling f l : t ~ kand shaking until hydrolysis w ture of 40 ml. of concentrated hydrochlor nitric? ac.id was added t o dissolve the gernia I t is po$*il)leto calculate the contribution of these secondary re.sion, resulting in a single liquid phme that xctions and correct for their interference. tilled, Another interference encountered in the spectrometric anal Copper and arsenic carriers (25 mg. each) were added to the of neutron-activated germanium samples is the presence of :t nlplp i n the distilling flask. The copper served as a hold-back i,rirr for the nonvolatile impurities, whereas the arsenic carrier number of large gamma photopeaks in the scan of the sample, assiRted in the subsequent distillation of arsenic trichloride. The due to the nuclides of germanium, the major component. These solution as distilled down t o a volume of 2 to 3 ml. under oxidiz1)hotopealie interfere in the measurement of the photopeaks of ing conditions resulting from the addition of the nitric acid. the trace impurities. I t is necessary, therefore, t o separate This suppressed the distillation of arsenic. Xddition of 10 ml. of mixed hydrochloric and nitric acids (9 to 1 ) and distillation to a c.lieniicall?-the radioactive germanium from the gamma-emitting small volume were repeated two more times. After the third i i n p u r i t i ~in~the sample. distillation, the receiver containing the distilled germanium \Yhcn germanium tetrachloride is irradiated, the chloride atoms tetrachloride v a s removed and replaced by one containing 20 nil. f'orm radioactive chlorine-36 and chlorine-38, with half lives of 4 of water. The delivery tube of the condenser was permitted to dip just below the surface of the water. Ten milliliters of 48% X 105 years and 37 minutes, respectively. Chlorine-36 is a pure hydrobromic acid were added to the reqidue in the distilling flask hetn emitter, while chlorine-38 decays by beta and gamma to reduce arsenic(S') to arsenic(III), which was then distilled over emission. Consequently these nuclides do not interfere in the :is the trichloride. The solution was distilled to a volume of 2 measurement of activity because only the chlorine-38 emits to 3 nil. Addition of 10 ml. of hydrobromic acid and distillation were repeated twice more. The distillate in the receiving flask gamma photons and measurement is made 8 hours after removal containing the arsenic activity rras diluted to a known volume from the pile. Also, most of the radioactive chloride is removed and an aliquot was taken for measurement of arsenic-76, using during the chemical separation steps. the spectrometer. The residue in the distilling flask containing the nonvolatile radioactive impurities was then transferred to a 50-ml. beaker, evaporated to dryness, and analyzed with the EXPERIMERTAL spec t'rometer. 111 order to test the completeness of the separation of gerGermanium Samples. The nietliod has been developed to manium from the impurities, the amount of germanium present analyze for trace impurities in elemental germanium, germanium iri the arsenic distillate and the final residue was determined b\dioxide, and germanium tetr:ic-hloi,ide, and may be applied n-ith measuring the germanium activity k i t h the spectrometer. It some modification to other germanium compounds. was found that the arsenic distillate contained less than 0.1% Comparative Standards. Weighed amounts of pure elements of the germanium, whereas less than 0.01% of the germaniuni or the appropriate compounds were irradiated with the samples remained in the distilling flask. B y greatly reducing the concenfor eventual comparison with the unknowm tration of the gamma-emitting nuclides of germanium in the Germanium Standard Samples. There are no standard gerarsenic distillate and final residue, it was a relatively simple task manium samples available with known impurity content a t the to measnre the arsenic and other gamma-emitting impurities low concnentration ranges concerned in this study; therefore: it with the spectrometer without any further chemical separation. was necessary to prepare synthetic st:mdards to test t,he accuracy Measurement of Activity. All measurements of radioactivity and precision of the method. Germanium and pure elements or were made with a gamma scintillation spectrometer, using a compounds of the elements to be determined m-ere irradiated thallium-activated sodium iodide crystal as the detector. Desimultaneously. The germaninm had previously been analyzed tails of the instrument and techniques employed are included in a by activation analysis and found to contain only 3.1 X 10-6 in of arsenic per gram of germaniiim. The pure elements after previous paper by the authors ( 2 ) . Further details on the use of idiation viere dissolved and small known aliquots were added scintillation spectrometry for quant'itative measurement are described by Connally and Leboenf ( 1 ) . I n all cases, appropriate to the radioactive germanium in :t di*tilling flask and carried decay corrections 1%-ereapplied in calculating the quantities of through the procedure. trace impurities present, Determination of the half life, along Irradiation. A sample of appropriate size (0.1 to 1 gram o f solid and 1 nil. of germanium tetrachloride), depending o n the with the gamma energy of the photopeaks, established the raciiochemical purit,y of the measured photopeaks. amount available and the anticipated purity of the material, 4rsenic activity was determined by measuring an aliquot of the together with the corresponding pure elements used as cnomparaarsenic distillate with the spectrometer. Because gamma activity tive standards, !+-ere sealed in separate quartz ampoules for mas measured, absorption effects b y the liquid were negligible. irr:diation in the Brookhaven pile. When irradiated for 3 day:: at The gamma photopeak due to arsenic-76 was measured and coma flux of approsiniately 3.4 X lo'* neutrons per square centimeter per second, most of the elements of the periodic table prodiice pared with the corresponding comparative standard after appioradioactive species. The maxininm flux of the pile was eniployetl priate correction for radioactive decay. Arsenic-76 is also formed by :i secondary nuclear reaction (luring irracliation of the gerinxto produce tis high an activity as pogsible from the trace impurities
Table I.
(n,-y)Reactions of Germanium Isotopes
(,(,$
I-
322
ANALYTICAL CHEMISTRY
nium sample, which necessitates calculating the amount produced ( 3 , 4)and subtracting this from the total arsenic-76 measured in the sample. The residue containing the nonvolatile impurities was analyzed with the spectrometer; q~iantitativemeasurement of the respective impurities was accomplished by comparing the photopeaks with those obtained from the corresponding comparative standards. Because galliuni-i2 is formed by a secondary reaction during irradiation of germanium, the amount produced in this manner was calculated and subtracted from the total gallium-i2 measured in the sample (3). It should be noted that with different conditions of time of irradiation and neutron flus, varying amounts of gallium and arsenic will result. Thus, it may be possible with the proper choice of conditions to minimize the effects of these reactions (4). The conditions of irradiation employed in this method, however, were chosen t o activate as many trace impurities as possible in the same irradiation with consequent sacrifice of optimum conditions for minimizing these side reactions. R E S U L T S .4ND DISCUSSION
Only those elements which result in radionuclides having hall lives greater than approximately 4 hours and less than 200 days could easily be determined by this method. This interval was chosen as most convenient because measurement of the activity in the samples started approximately 8 hours after removal from the pile. Radionuclides with half lives much shorter than 4 hours could not be detected conveniently in this laboratory when present in trace amounts, whereas nuclides with half lives much greater than 200 days would be insufficiently activated for measurement under the conditions of the irradiation employrcl.
Co Ba La H I Ta W
Re
Os lr Pt
Au He T I Pb
Bi Po At Rn
Fa Ra Ac
Table 11.
Sainyle Germanium dioxide
Gerinaniuni dioxide
.4nalysis of Trace Impurities in Germanium Samples Impurity -4s Na cu Zn
Radionuclide As'6 Na*: CUB4 Zn59
-4s Sa cu Zn
.4S'6
Measured Measured Gamma Half life, Concn., Energy, 1I.E.V. Hours % 0.55, 1.22 26 1 . 5 X 10-4 1.37 15 3 . 9 x 10-5 0.51 12.5 1 . 6 x 10-6 0.44 14 1 . 4 x 10-3 0 .55, .22
1.5x 5.6 x 1.3 X 1.3 x
26
Na2' rush Zn69
1.38 0.51 0.44
26
15
13 14
Germanium dioxide
-4s Na Zn
Na24 Zn69
0 55, . 2 1 1 38 0 44
Germanium tetrachloride
-4s Na cu
.4s'@ Na24 Cu64
0.55, .22 1 38 0.51
26
Germaniuni tetrachloride
-4s Na
As76 Ka2'
0 . 5 5 ,1.22
26
Gernianirini
-4s
As76
0 5,5,1.22
15
13 15
3 . 8 X IO-' 2 . 5 x 10-5
26
3 . 1 X 10-4
secondary nuclear reaction. Under the conditions of irradiation employed in this method, the apparent arsenic and gallium contents due to secondary nuclear reactions are 4.2 X 10-7 and 1.8 x 10-7 gram per gram of germanium, respectively. Accuracy and Precision. The results of the analysis of the standard germanium samples are shown in Table 111. The germanium used in the preparation of these samples had previously been analyzed and found to contain 3.1 X 10-6 gram of arsenic per grain of germanium. Consequently, the arsenic content of these samples is the sum of the arsenic originally present plus the known amounts added. The arsenic and gallium values obtained in the analyses have been corrected for the amounts of these elements produced in the Pecondary nuclear reactions during irradiation.
Table 111. .4nalysis of Germanium Standard Samples Amount of Inipurity Element, Gram Present Found 1 . 2 x 10-6 1 . 3 X 10-6 3 . 7 x 10-6 3 6 x 10-6 0 . 9 5 x 10-5 1 3 x 10-5
Impurity Element As Ga Na
0,2298
48 Ga Na
3 . 0 x 10-3 1 . 3 X 10-5
1.5
x
10-6
1 . 3 X 10-6 3 . 1 x 10-6 0 . 9 8 X 10-5
Based on a 3-day irradiation a t a flux of 3.4 X 10'2 neutrons per square centimeter per second and measurement of the short ha1f;lived isotopes within 8 t o 10 hours after removal from the pile. Elements In solid blocks form gamma-emitting radionuclides measurable on scintillation spectrometer. Elements in broken blorks form only beta-emitting radionuclides.
0.1366
.48
1.2 3.6 1.3
x x
10-0 10-6 10-6
1.2 2.9
1 1
x x x
10-9 10-6 10-5
10-6 10-5 10-6 10-0
1.0
x
10-0
There are, of course, exceptions to this general classification, depending upon the nuclear properties of certain impurity elements. Thus, if the corresponding stable isotopes of these impurity elements possess optimum cross sections and abundances, the activity produced by irradiation may he sufficiently high for detection beyond the limits of the half lives mentioned. Also, if the impurities are present in larger amounts, greater activity will result. This method was designed to determine as many elements as possible with a single irradiation of a relatively pure sample of germanium; those elements which can conveniently be determined in trace amounts are shown in Figure 1. The results of the analysis of several samples of germanium, germanium dioxide, and germanium tetrachloride are given in Table 11. The arsenic values have been corrected for the amount of arsenic formed by the germanium during irradiation. Gallium was detected in all of the samples; however, the amount was equal t o that which was calculated to be formed by the
0 1957
x x x x 1 7 x 6 6 x 5 4 X 5 7 x 1 3 x fi 6 x J 4 x
E u Gd Tb Dv H o Er Tm Yb Lul
Th Pa U Np Pu An Cn 97 98
Figure 1. Trace elements producing measurable radioactivity
-4
1 . 5 x 10-4 3 . 4 x 10-3 5 3 X 10-.0
15
Germanium, Gram 0 . 1538
(CelPnlSm
10-b 10
2 . 2 X IO-: 2 . 4 x IO~.j 2 . 2 X 10 1
14
1.38
10-6 10.6
Ga Na
0.1176
.4s Na Zn CU -4s Na Zn
cu
0 1437
.4s Na Zn
c 11
1.1 6.6 5.4 5.7
x
10-6 10-5 10-5 10-6
10-6
10-5 10-5 3 7 X 10-6
6 . 1 X 10-5 3 . 9 X 10-5 3 . 9 x 10-0
Eiroi
5% - 7 7
2 8 -27 -13 -14 -25 0 -19 -15
-
9.1 7 6 -28 -32
1 . 7 X 10-6 x 10-5
0 -27 -30 -32
1.2 5.9 3.8
-
4.8
3.8 3.9
x x x x x
10-5 10-6 10-6 10-5
10-5
4 . 0 X 10-6
7.7
-11
-30 -30
Although the precision of the method is good, never exceeding an estimated standard deviation of 13% for triplicate analyses of the respective elements, the accuracy of the determinations appears t o be low b y as much as 30% in some cases. It has previously been shown that an accuracy and precision of about 1% ' can be obtained in the activation analysis of trace impurities in silicon and aluminum, where scintillation spectrometry is performed directly on the irradiated sample without any chemical
V O L U M E 28, NO. 3, M A R C H 1 9 5 6
323
manipulation involved ( 2 ) . The major part of the error in the present method, therefore, can be attributed t o chemical loss during the separation procedure required before the ganimn spectrometric analysis could be performed. The low values obtained in the determinations may be explained by the fact that it \vas impossible t o remove all of the activity from the distilling flasks, even though quantitative washing technique!: were employed. In every instance some of the activity from the residue adhered to the walls of the flask. These determinations were performed on samples containing impurities in the range of 10-6 to 10-'gram and involved chemical sepnratione. I n view of these conditions, the method exhibits good accuracy and precision.
ACKKOW LEDG\l E \ T
Ac~Lnoivledyrnent is gratefully given to I). H. Baird for hi:: many valu,zble suggestions and criticisms. LITERATURE CITED
(1) C'onnally, R. E.. Leboeuf. 11.B., = ~ s . L L . CHEM.25, IO95 (1953). ( 2 ) Ilorrison. G. H., Cosgrove. J. F.. Ibid., 27, 810 (1955). (3) Rubinson, W., J . Chem. Phys. 17, 542 (1949). (4) Snirtles, -4.A , . Pate, B. D., - 4 s ~CHEM. ~ . 24, 717 (1962). ( 5 ) Szckely, G., Ibid., 26, 1500 (1954).
R E C E I V Efor D review September 27. 1955.
Accepted January 5 , 1956. Pitrsbiirgh Conference on Analytiral Chemistry and Applied Spectroscopy. Pittshrirgli, Pa.,February 1950.
X-Ray Diffraction Patterns of Some Guanidine Derivatives LOHR A. BURKARDT Chemistry Division,
U. S. Naval Ordnance Test Station, China Lake, Calif.
k-ray diffraction patterns are a convenient means of characterizing crystalline compounds. Such data are presented here for a number of guanidine derivatives.
I
S THE course of various studies, x-ray powder diffraction
data have been accumulated on the following compounds: nitroguanyl hydrazone of acetaldehyde, phenylacetalnitronminoguanidine, nitroguanyl hydrazone of cinnamaldehyde, l)enzalnitroaminoguanidine, nitroguanyl hydrazone of aceto-
'I'able I. d . .1. ]/I1 Sitroguanyl hydraeone of acetaldrhyde 12.27 1 8.94 3 7.97 1 ?.25 9 4.71 5 .i13 10 :ibs 6 3.50 5 3.40 9 3.20 7 s 04 4 2.85 ? 2.68 2 56 2 2.43 7 2.35 1 2.27 1
2 13
3.04 I 01 1.82 1.77 1 72 1.03 1.58
1.53 1 .50
0
1
2 1 2 1
1 1 1 1
P iiPhyiacetalnitro-
uiiiinoguanidine 11 11 5 9 5li 3 6 54 7 4 74 4 Q 49 8 4 li 7 g5 4 9 3 67 3 51 7 3 36 10 3 12 1
x
X-Ray Diffraction Powder Data d, A. I/Il Phenylaretalni troaniinogrianidine (Contd 1 2.98 2.84 1 2 71 i 2 6-2 1 2,s: 2 2,2li 2 . 1:: 1.97 1.ti> 1 52
1 2 1
1
1
Nitroguanyl hydrazone of cinnamaldehyde 14,4R 9 07 8 13 7.30 6.81i 5.07 4.74 4.54 4.31 4.01 3,5(i 3.46 3.34 3.05 2.98 2.80 2.59 2.43 2.31 2.18 2.09 1.94 1.82 1 65
d , .4. I/II Benaalnitroarninoguanidine 9.03 3 6.44 ( i . 11
3.72 5.28 4.55 4.3' 3 75 3.60 3.16 2.91 2.27 2 17 2.07 1.39
1
9 >
8
2.18 2 I4 2.02 1 q7 1.72 1. (i6
3 3 10 1 1 1 1
1
4 30
> > 1
1 1 1 1
3 , li0 3 31
3,Ii 3.03 2.9; 2.81 2.72
1
2.54 2 38 2.33
1
2.16
1
'2 24
;
Kitroguanyl hydrazone of acetophenone
4.01'
Phenylnitroguanidine 7.72 1 6 71 2 5.31 9 5.13 8 4 .88 6 4.52 6 4 07 6 ;i,m 4 :i . 34 10 :%li 4 3 .04 5 Y 96 2 2,s:i 7 2 Ii.3 1 2 a.5 2 2 . 47 1 2 41 29
1
1 3
Table I. (Continued) d . .4. 1/11 Ktroprianyl hydrazone of aretophenone (Contd.) 2.09 1 2 02 1 1 9(! 1 I 87 1 1 81 1
1 4
4
(i
1
1
1 1 2 1 1 1 1
l-Acetarnido-3nitroguanidine ?,?7 '9 r l . .a0 2 5.0s 1 -1.34 10 4.09 9 3 . 7l~l 2 :i , 3.2 i) :3 . 12 2 2.98 7 2 . 8fi > 2 74 5 2.56 ! 2 47 2.37 2 2.?,2 2 .I 2,; 1 9 18 2 2.12 2 0:: 1.97 1.91 1.89 1.85 1.73 1.66 1.59 L . .j4 1.39
> 1
2 1 2
1
1 1 1 1 1
d , A. I/I1 1-Amino-I-methyl2-ni troguanidine 8.46 7 7.73 7 4.91 10 4.18 3 3.83 7 3.73 2 3.63 8 3.30 9 3.n2 7 2.93 4 2.82 5 2.64 2 2,54 3 2.47 2.38 2.29 2 2.22 5 2.12 2 2.02
1
d . .1 I/II .Vitr oguanidine hydrobrornide 5.63 3 5.18 10 4.02 8 3.79 3 3.55 1 3.41 7 3 .: I 8 3 21 8 3.0Y 7 2.92 7 2.82 3 2 , i:3 3 2.64 3 2.59 ,'I 2.47 :3 2.37 3 2.31 > 2.20 3 2.21 2 2.16 2.09 2 2.06 2 1.94 3 1.90 1 1.84 1 1.78 2 1.74 > 1.71 2
1
1. Rli
2
1.90 1.81
1.79 1.68 1.58 1 ,j 6 1.31
1.47 1.44 1.41 1.35 1.33 1.21 1.18
21 1
2 1
2 I 1
1 1 1 1
Met hylnitrogusnidine 7.73
5.70 5.2'7 4.71 4.?l 3,8ii 3.72 3 . .jG 3.28 3 12 2 74 2.59 2.49 2.37 2.23 2.16
2.12 2.01 1.93
1.87 1.78 1.70 1.63 1.60 1.50 1.47 1.42
10 3 3
4 Y
4 9 7 9 9 4 4 1 : 4 4 4
2
1
2 3 i
1 1 2 1 1
1
1.31 1.49 1.41; 1.43 1 39 1.37 1.31 1.21 I 10
1 2 1
1 1
I 1
1 1
1
Nitropuanidine hydrochloride G.13 4 5.57 8 3.11 4.09 4.03 3.87 3 ,x:3 3.10 2.81 2 114 2.37 2.42 2.37 2.29 2.21 9.09
2.04 1.9'7 1.89
1.73 1.70 1.67 1.59
6
5 8 3 8 10 7
4 4
4
5
1
1 1 1 1 2 2 1
