1740
ANALYTICAL CHEMlSTRY
C Yaroniatics are probably a c c u i x t r 10 =tlyoonly if the amount of C9's is less than 10 o r 15%. ACKNOWLEDGMENT
Permission of the Humble Oil and Refining Co. to release the information contained herein is gratefully acknowledged. An evpression of thanks is also due C. T . Shen-ell for his assistance in making the statistical calculations. The kind assistance of C. R. Middleton in procuring and analyzing the aromatic mixtures is gratefully acknowledged. LITERATURE CITED
( l i .lm. SOC.Testing Materials, Tentative Alethod, Designation
(3) l31ow11, R. A , , Taylor, R. C.. Melpolder, F. W., and Toung, W.S., Ibid., 20,5 (1948). (4)Conrad. A. L.. Ibid.. 20. 725 (1948). (5) Grosse, A. V., and Wackher, R. C., Ibid., 19, 992 (1947). (6) Kurtr, S S., Jr., M~lls,I. R., Martin, C. C., Harvey, R. T., and Lipkin, M. R., Ibid., 19,175 (1947). (7) Mair, B. J., J . Research Natl. Bur. Standards, 35,435 (1945). ( 8 ) Natl. Bur. Standards, "Selected Values of Properties of Hydrccarbons," Washington, D. C., Government Printing Office, 1947. (9) Purdy, K.M., and Harris, R. J., ;INAL. CHEM.,22, 1337 (1950). (10) Shepherd, M.,and Hippie, J. A , , Ibid., 22,23 (1950). (11) Spakowski. A. E.,Evans, A , and Hibbard, R. R., Ibid., 22, 1419 (1950). (12) Washburn, H.W., Wiley, H. F., Rock, S. bf., and Berry, C. E., ISD. ENG.CHEM.,ANAL.ED.,17,74 (1945).
D 875-461'.
( 2 ) Brown, R. -4., ; L u . 4 ~ . CHEY.,23,430 (1951).
R E C E I V EApril D 19. 1951.
Ultravielet and Visible Absorption Spectra in Ethyl Alcohol Data f o r Certain Nitric. Esters, Nitramines, Nitroalkylbenzenes, and Derivatives of Phenol, Aniline, Urea, Carbamic Acid, Diphenylamine, Carbazole, and Triphenylamine W. A . SCHROEDEH, PIIILIP E. WILCOX', KENNETH N. TRUEBLOOD*, AND 4 L B E R T 0. DEKKER3 California Institute of Technology, Pasadena, Calif. Spectrophotonietric information for 135 organic compounds w-as gathered to aid in the identification of compounds that had been isolated chromatographically in other studies. Absolute ethyl alcohol was thesolvent usedfor thedetermination all the spectra. The data are presented in table and graph and for the most part of are only roughly quantitative-that is, their accuracy is estimated to be 2 to 5'7'; more precise values, however, have been determined and recorded for certain compounds. The spectra of most of the substances have not previously been reported in the literature. No attempt has been made to present a correlation between structure and observed spectrum.
I
S T H E course of chromatographic-sprctrophotonietricstudies of smokeless powder and of the derivatives that are formed from several stabilizers during accelerated aging of such powder ( I 7-19, 22), the ultraviolet and visible absorption spectra of ethanolic solutions of a large number of compounds were determined in order t o aid in the identification and estimation of compounds after isolation from the chromatographic column. Only a small portion of these data has been reported in the abovecited papers and, because there is in the literature little or no recent spectrophotometric information about most of the 135 compounds that were investigated, the present paper is a compilation of the spectra which were determined. EXPERIMENTAL
Spectrophotometer and Its Use. All absorption s ectra were measured by means of a Beckman quartz photoeyectric spectrophotometer, Model DU (S), which was equipped with quartz cells. No attempt was made t o control the slit width, but rather the "sensitivity', was set a t 3 to 4 turns from the counterclockwise limit and the slit width was varied as necessary to balance the instrument. The slit width is relatively unimportant unless the compound has very sharp maxima as, for example, carbazole. Measurements were made from the shortest attainable wave length (usually less than 215 mp) t o a wave length a t which absorption was inappreciable-for example, colorless compounds usually were not measured a t wave lengths longer than 300 or 350 mp. The frequency a t which reading4 of optical density were taken depended upon the intricacy of the
' Present address, Harvard Medical 3
School, Boston, Mass. Present address, University of California, Los Angeles 24. Calif. Present address, Aerojet Engineering C o r p . , I z u - a , Calif.
spectral curve; around relatively qharp maxima and minima, readings were taken a t intervals of 1 mp for about 5 mp on either side of the maximum or minimum, whereas in other regions of the curve, intervals of 2 to 5 m p ere used. Solvent. Unless specifically noted otherwise, the absorption spectrum of each compound was determined in absolute ethg 1 alcohol. Commercial absolute ethyl alcohol without drying or further purification was used. I n most instances, the compound was simply dissolved in ethyl alcohol and the spectrum of the solution was measured. HOMever, in the case of a few compounds whose spectra are especially sensitive to the presence of acid or base, the spectrum was measured after the addition of 1 or 2 drops of 6 S hydrochloric acid or 6 S sodium hydroxide to 100 ml. of solution.
It must not be inferred that only those spectra which were studied in acidic or basic solution are affected by the acidity or basicity of the solution; certainly, the spectra of many of the nitrated compounds would also be so affected. Roughly Quantitative Procedure. For many purposes, sufficient information for practical use, such aa qualitative identification, could be obtained by determining the shape of the curve and the spectrophotometric constants Rith less than utmost precision. In such instances the following roughly quantitative procedure was used. About 10 mg. of compound were carefully weighed and dissolved in ahsolute ethyl alcohol and the solution was diluted in a volumetric flask. h preliminary examination of the curve was then made and, if necessary, the solution was diluted quantitatively until the optical density of the principal maximum xas betneeii 0 4 and 1.0. The entire spectral curve was finally determined at this dilution, The accuracy of the roughly quantitative Ixocedure is discuwed belov .
V O L U M E 2 3 , NO. 1 2 , D E C E M B E R 1 9 5 1
1741
niasinia and niiiiinia :it iclt~ntiral\\-ave Imgths but differ in t hie ratio, and it is also an aid in assessing thr purity of a ~ u l i s t a n c ~ t ~ Jvhich has been isolated chromatographically because a n inipurity is unlikely t o alter a spectmnl in such a a.ay that this ratio remains constant,. Sources of Compounds. The sources of the c0mpound.q \vhoke spectra are given in this paper niay be placed in one of fiw categories.
Quantitative Procedure. When 'spectrophotometry !vas to be used for the quantitative determination of a compound that had been isolated from a chromatogram, it was necessary to know the spectrophotometric constants with an accuracy greater than that given by the roughly quantitative procedure, and accordingly t h e following method was used. The compound was purified by the best available method and it' it \vas a solid was finally crystallized if possible from petroleum ether in order to aid in the removal of solvent by drying. Thc finely divided solid was dried in an Abderhalden apparatus under c.ontiriuous suction a t high vacuum and at a temperature which depended upon the melting point and stability of the compound. The effect,iveness of the drying was checked by redrying a part of the material and comparing the spectrophotometric data o'f the tn-(I portions. Liquid samples were repeatedly distilled until c-onstant data were obtained. A portion of 50 t,o 100 nig. was weighed in a closed Jveighing pig and dissolved in absolute ethyl alcohol. The solution was diluted in a volumetric flask and several aliquot portions were variously diluted so that the conformity of the substance to Beer's law could be t,ested. I n order to avoid errors due to ch:~nges in the temperatmureof the solution, the adjustment of the volume was delayed until all preparations for spectrophotoniet].. had been completed and the solution had attained the temperature of the atmosphere around the instrument. After the adjustment to volume had been made, the optical densities at maxima and minima were carefully and quickly measured immediately after the cells had been inserted int,o the instrument.. Xft,er t,hese memurements had been completed, t'he remainder o f the spectral curve was det,ermined in the same manner as in t lie roughly quantitative procedure. Spect,rophotomet,ric data determined by the quantitative prowdure are indicated in Table I by reference t o footnote c. Corrections Applied. Before spectrophotometric data were calculated, the measured optical densities a t maxima and minima were corrected for the optical density of the solvent cell and solution cell relative to each other a t the wave length of the maximum or minimum when both cells were filled with pure solvent and also for the deviation of the thickness of the solution cell from 1.000 em. The sum of these corrections usually was of the order of 0.005 to 0.010 unit of optical density-that is, about. 0.5 to 27, of the optical density a t maxima. Large corrections usually indicated dirty cells; cleaning with a cotton sv,-ab saturated with a 17, aqueous solution of Aerosol OT was usually effective. Definition of terms. I n the present paper, the various spectrophotometric terms used are defined in the following manner: The optical density, D ,is log (Io/Z),where 10 equals the int'ensity of the incident light and I the intensity of the transmitted light. The molecular extinct'ion coefficient, e, is defined in the con~ e n t ~ i o nway a l as D / k , where D is optical densit I is tjhe length of solution in centimet,ers traversed by the lig?h and c is the concentration in moles per liter. The symbol I&"",. has been used t.o designate this quantity in previous papers (18, 19, 22).
1. Comniercial!y available samples purified by crysta1Ii~~1tion or distillation, whose propert,ieE were in satisfactory agreement with those described in the literature. In this group are numbers 1. 2. 8. 20. 21. 22. 24. 25. 26. 28. 31. 32. 34, 36, 57, S l . 124, and 125'in'Table I. 2 Samples obtained from laboratories under SDRC contr:i( t , fiom government explosives laboratories, and from the expicisives industry. This group is made up of 3 to 7, 9 to 19, 23. 35, 48, 59, 60, 61, 63, and 126. 3. Compounds piepared by procedures published in the literature, whose properties were in satisfactory agreement n I t h those described in the literature. This category inclutlec 30, 37, 39, 41, 45, 47, 49, 50, 52, 66, 71, 74 to 78, 80 to 83, 87, 102, 107, 108, 118, 119, 121, 122, 123, 128, 130, and.131. 4. Substances whoee sources have been descnbed (18, 19, 22). Compounds 27, 29, 33, 38, 40, 42, 43, 44, 46, 55, 58, 62, 69, S f i to 101, 103 to 106, 109 to 117, and 127 fall in this group. 5 . Kern compounds for 11 hick methods of synthesis have I)ep11 published (go, 21, 24) or previously deccrihed compountls p ~ e pared by new method< Listed here are 51, 53, 54, 56, 64, (i5, 67, 68, 70, 72, 73, 79, 85> 120, 129, and 132 to 135. ,
I
Special mention bhould tx made of compounds 9 to 19, n hi( h are designated in Table I only by the alphabetical nomenclature of those IT ho isolated them in the study of methods for the nmnufacture of the explosive RDS. The chemistv of thew compounds haB been d e s c r i k l by Bachmann and Sheehan ( 1 ) and \TTright and conorher+ ( 2 6 ) , and the stmctuwa are a.s f o l l o ~ v ~ :
/
RDX
n'hen spectrophotometry is used t o determine the concentration of a solution, the molecular extinction coefficient is an awknard quantity to use in calculation. However, a convenient factor is the ratio C / D where D is the optical d p i t y and C is the concentration in milligrams per 100 ml. If the further qualification is made that the t,hickness of solution be 1.000 em., the units are niilligrams per 100 ml. for 1.000 em. .kxordingly, if the optical density of a solution is determined, a t a maximum or other wave length of known C / D , the concentration in milligrams per 100 ml. is easily calculated by multiplying the ratio by the optical density of the solution. The conventional niolecular extinction coefficient results if the ratio C / D is divided into ,100 times the molecular weight of the compound. -4quantity which is useful for characterization of an absovtion spectrum is the ratio of the optical density a t a maximum, D,,,,,, to that a t the nearest minimum of shorter wave length, Dmin., which ratio may be written Dmax,/D~,im. I t is easily shown that for a given spectivni this ratio is independent of the Concentration and thickness of the solution used for measurement. The ratio is helpful in identification because different compounds niay have
CH2-S /
so,
T 0,
\
'so:
HMX 1
I
hO*
ANALYTICAL CHEMISTRY
1742
Table I. Compound NO.
1
2 3
4
Figure
.. .. ..
Position of Max., Xin., mir mir
S a m e of Compound
KO.
..
Spectrophotometric Data for Compounds in Ethanolic Solution
__.
Dmax Dmin.
C / D of Max.
x 10-3 of Max.
E
I. SITRIC ESTERS None observed D E G S (dieJhylene glycol dinitrate) Nitro,olycerin ( B G ) None observed P E T h (pentaerythritol tetranitrate) None observed Fivonite (tetramethylol cyclopentanone tetranitrate) None obserred 11. NITRAXIXES
8
fi
A9
10 11 12 13 14 15 16 17 18 19
la la la la lb lb Ib lb Ib IC IC lo IC lo
1 20 1.38
...
...
...
... .. .. .. ... ... ... ...
237
3.93
...
... ...
...
...
...
224-225 ... 227-228 . . 229-230 , . . None observed
..
111.
. I .
...
3 77 2.58 1.25 0.68 2.02 3.36 2.10 1.41e 1.85 2.23 2.19 2.2 2.10 2.72
12.0 15.3 11.0 6.5 8.5 21.0 15,s 9.8 16.2 16 20.4 15.6
6.4
2.56 1.44 1.275C 1.52 1.15
5.4 9.5 14.28 12.9 19.7
6.4
~-ITROALKYLBENZESES
20 21 22 23 24
Id Id Id Id Id
2-Nitrotoluenn 4-Kitrotoluene 2.4-Dinitrotoluene ( D X T ) 2.4-Dinitro- 1-ethylbenzene 2.4,6-Trinitrotoluene ( T N T )
25
le
2-Nitrophenol
257 273 239-242 241 227
26
le
3-h-itrophenol
27a
le
4-Kitrophenol ("neutral" solution) e
27b
le
4-Sitrophenol (basic solution)
28
le
2,4-Dinitrophenol
29a 29h 30a 30h
If If If
2,4,6-Trinitrophenol (picric acid) (acidic solution) 2,4,6-Trinitrophenol (picric acid) (basic solution) 2,4,6-Trinitroanisole (acidic solution) 2,4,6-Trinitroanisole (basic solution)
I\'
lf
221 218-21'2
-nitraminel
1.73 4.75
232-233 233 218
... 1.26
...
...
...
NITROPHEXOLS 345-317 272-273 330-334 269-271 229-230 311-313 224-226 401-403 233-235 291-294 252-284
2.01 2.62 1.49 1.88 1.11 9.3
307-309 244 302-304 249-250 222-221 252-2,54 310-312
...
> 100 , . .
1.16 1.13 1.07 5.3,s
272-273 231-234
335 313 357-359 281-285 h-one observed 488-491 4-14-446 411-412 320-326 254-256 240-242
133 16
1.07
4.42 2.32 6.6 2.49 1.45 1.31 1.97 0.73 2.55 2.01 1.81
3.14 6.0 2.11 5.6 9.6 10.6
4.2 1 63
7.1 19.0 5.5 9.2 10.2 5 4 14.1
1.48 1 01 2,65
16.4 24.1 9.2
2 6 2.8 0.83 9.2 0 87 0.91 2.18 1.24 1 87 1.74 3.lfi 3.16
5 3 4.9 16.6 1.50 15.9 15.2 6.3 14.8 9.8 10.5 4 81 4.81 17.9 1.92 11.0 8.6 6.7 31.3 5.6 6 2
\'. DERIVATIVE0 O F AXILITE 31
Ig
2-h-itroaniline
32
Ig
3-Sitroaniline
33
Ig
4-Nitroaniline
34
Ig
2.4-Dinitroaniline
35
1g
4-hIethyl-2-nitroaniiine (m-nitro-p-toluidine)
36
lh
A'-Ethylaniline
37 38 39
Ih lh li
A'-Ethyl-.T-phenylformamide ,Y-Sitroso-S-ethylaniline 4-Nitroso-T-ethylaniline
40
li
2-Piitro-S-ethylaniline
41 42
li li
IV-Nitroso-2-nitro-.Y-ethylaniline 4-h7itro-.Y-ethslaniline
43
li
N-Kitroso-4-nitro-S-ethylaniline
44
2a
2,4-Dinitro-iV-ethylaniline
45
2a
2,4.6-Trinitro-N-ethyIaniline
403-404 276 231 370-377 235 371-372 228-229 336 257 226-227 415-420 280 230 293 246.5 232-234 270-273 415-416 271-273 425 279-280 232 240-242 386 231-232 312-314 221-223 347 259-261 408-412 335-338
14.6
313 263
1.36
...
...
2 12
317-319
...
,..
276
17.6
285 242
6.17 1.21
320 268
l5,l 1.21
272 219
1.96 3.97
...
,..
...
,..
...
... ...
'i.09
240 330-337,
52
325 266
18.9 1.28
226-229 280-283
1.06 22 7
...
,..
...
...
..,
...
247-248
...
6.32
290 245 381-385 281-284
8.4:
...
,
1.11 1.li 4.88
0.85
6.3 1.1 1.74 2.24 0.48 2.7 2.7 3 6 0.7s 1.70 0.88 2 16 1.30 1 .s5 1.27 2.36 4.26 1.75
4.61
21 .o 11.5 18.9 7.7
15.0
10.5 16.6 8.9 6.0 14.6
0 Structure is given in text. b Because maxima of R D X and cyclonite oxide are a t wave lengths where accurate measurement of optical density is difficult optical density a t 235 a n d 2% m p , respectively, is used for quantitative calculations, Values of C / D a t these points are 2.12 and 3.47. respectively, and ar; probably precise to within
1%. C
d
*
Determined b y quantitative procedure. 4 T X was dissolved in 1yoof dioxane in absolute ethyl alcohol. Compound is unstable in solution. T h e n acid is added t o "neritral" solution of 4-nltropheno1, spectrum is practically unchanged.
V O L U M E 23, NO. 12, D E C E M B E R 1 9 5 1 Table 1. Compound No.
Figure
46
2a
1743
Spectrophotometric Data for Compounds in Ethanolic Solution (Continued) Position of Max., Jlin., mp mp
Name of Compound
NO.
e
X 10-2 of Max.
Literature
21.8 1.81 8.6
(9,49)
32.4
(6. 8 )
V. DERIVATIVES O F ANILINE(Continued)
47 48
2a 2a
4-Nitroso-S, S-diethylaniline Tetryl! (S-2,4,6-tetranitro-N-methylaniline)
VI. 49
2b
1-Phenylurea
50 51
2c 2b
1-Ethyl-1-phenylurea 1-Ethyl-3-phenylurea
52
2b
1 1-Diethyl-3-phenylurea
53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72
2c 2c 2d 2d 2b 2d 2e 2R 2e 2e 2e 2e 2e 2P 2f 2f 2f 2f 2f
1,3-DiethyI-l-phenylurea I-Phenvl-1.3.3-triethvlurea
~
1,l 3-Tridhenylurea
392-395 315-317 235-237 424- 426 274-276 235-238 225 DERIVATIVES O F UREA 268-275 237 235-237 275-277 240-241 270-273 239-241 243
~
2g
l-Ethyl-l,3,3-triphenylurea lI1,3,3-Tetraphenylurea 2-Kitrocentraliteh 4-Nitrocentraliteh 4,4'-Dinitrocentralite h 2,4,4'-Trinitrocentraliteh 2,2',4,4'-Tetranitrocentraliteh 4-Sitro-.V-ethylcarbanilide
73 74
2g 2g
4-Nitro-S'-ethylcarhanilide S-Nitrosocarbanilide i
75
2h
3'-Phenylurethane
76 77 78
2i 2i 2i
AV-RIethyl-.V-phenylurethane .\'-Ethyl-A'-phenylurethane A'- (o-Tolyl)-urethane
79
2h
.V- (p-Tolyl)-urethane
80 81
3a 2h
Methyl S-phenylcarbamate Isopropyl A'-phenylcarbamate
82
3a
n-Hexyl .\?-phenylcarbamate
83 84 85
2i 3a 2h
Methyl S-ethyl-,V-phenylcarbamate N S-Diphenylurethane N:S-Diphenylcarbamic anhydride
334-338 240-241 327-330 230-232
VII.
320-823 283-287
13.2 2.1
332-343 244-246 224-227
90 1.9 1.2
...
...
1.2
220-2210 263-264
1.48 1.14
267-269
...
1.03
226 230-231 223 227-229 227-228 2 17-21 9g 228 228 232 233 234 227-228 243-245 234 229-230 277-278 259 264-266 280-285 289-290
1.58 2.58 1 55 1.30 8.1 2.1 1 66 1.60 1.21 1.34 1.34 1.98 1.47 1.51 1.22 1.93 2.26 1.49 1.02 1.80
266-267 215-216
6.9 1.37
...
...
...
...
VIII.
...
259-261
DERIVATIVEB OF CARBAMIC -kClD 273-275 257-258 235-236 232-233 215-216 231 215-216 269-270 231 279 238 235 274 235-236 274 235-236 229 238 236-237
...
256-257 218 261-263
... ... 258-260 ... 258-260
...
...
222 220-221
... ,..
...
...
1.3
...
1.75 1.51 1.28 1.40 1.66
...
... 1.25
...
1.25
...
.1.. .5 4
1.44
0.89 10.7 2.26 0.55 3.28 5.6 1.15
25.0
12 0.77 4.72 16 0.83 18 1.05 5.30 3.05 1.86C 1.96 0.57 1.47 1.80 1.98 2.70e 3.07c 3.50 1.24 2.09 1,79 2.52 3.80 2.36 2.80 3.8 3.39 1.49 1.69 1.32
1.1 17.7 3.48 1. o 19.8 1.1 18.3 3.63 7.2 11.4 12.3 37.2 16.3 13.4 13.5 8.9 8.7 9.3 23.2 15.1 20 3 12.4 e.2 15.2 14.4 11.8 8.4 19.1 16,9 18.3
19.5 0.98 2.6 3.5SC 34.9 2.22c 18.3 1.01 0.96 21.3
0.85 16.8 6.9 5.a9 0.51 8.1 0.98 17.7 15.7 0.84 17.1 0.84 17.1 5.2 13.5 25.5
1.05
26.3 1.29 3.44 1.78C 1.60
5,4
3.18 (19)
DERIVATIVES O F DIPHEYYLAXIUF 7.21 0.835C 20.25 (18) 285 249 Diphenylamine i 3b 86 1.67 1.38 14.3 240 224 N.N-Diphenylformamide 3b 87 1 . 4 4 3.50C 5 . 6 6 295-296 259-260 N-Kitrosodiphenylamine 3b 88 5.8 0.97 20.4 405-407 279-281 4-Nitrosodiphenylamine (acidic solution) 3b 89a 1.5 4.8 4.13 258-260 237-240 9.0 0.75 26.4 390-392 323-325 4-Sitrosodiphenylamine (basic solution) 3b 89b 1.1 4.3 4.6 291-294 275-276 1.1 4.0 5.0 255-258 242-245 3.24 6.6 15 422-423 323-327 2-Sitrodiphenylamine 3c 90 1.50 14.3 1.37 267-259 238-239 1.63 13.1 1.04 221-2220 214-2150 13.4 1.01 21.2 390 305-306 4-Nitrodiphenylamine 3c 91 2.07 10.3 267 None observed S-Nitroso-2-nitrodiphenylamine 3c 92 2.95 1.78 13.7 317-320 247-249 .V-Nitroso-4-nitrodiphenylamine 3c 93 2.76 9 4 7.2 417-423 315 2,2 '-Dinitrodiphenylamine 3d 94 1.56 16.6 1.25 264 235-237 1 . 7 1 1 5.2 1 . 0 3 225 220 7.6 1.52 17.0 (14) 350-351 291 2,4-Dinitrodiphenylamine 3d 95 1.03 2.00 13.0 231-232 222-224 I Compound is unstable in ethyl alcohol and spectrum changes slowly in a few days. Maximum (or minimum) which occurs a t a wave length shorter t h a n 220 mp in spectrum of this compound is in a region where i t is difficult to meamre optical density accufate!y; therefore position and constants are uncertain. h Named as a derivative of centralite, which is 1,3-diethyl-1,3-diphenylurea. i Unstable in solution. j Diphenylamine in crystalline form and in solution is photosensitive a n d epectrum changes very slowly if solid or solution is allowed t o stand even in dif(Continued on nezt page) fuse light. Change is inappreciable in several days.
1744
ANALYTICAL CHEMISTRY Table I.
Compound NO.
Figure NO.
96
3d
Spectrophotometric Data for Compounds in Ethanolic Solution (Continued) ~~
S a m e of Compound
Position of Max., Min., mp mp
Dmax. __
C/D of
1.31 3.66
Dmin.
X 10-8 of Max.
Literature
1.86 2.18 1.54 0.69 2.24 1.93 1.53 1.60 2 13 1.98 1.69 1.41 1.77 2.29 1.56 1.54 2.03 1.56 2.09 3.67 2.58 1.5
13.9 11.9 16.8 37.6 11.6 14.9 18.8 18.0 14.3 15.4 18.0 21.6 17.2
(14)
13.3 19.5 22.7 17.2 22.4 18.9 10.7
(7)
17.0 29
(12)
5.29 4.51 1.04c,1 0.894CvI 0 425Cil 4.62 5.08 1.08 0.88
3.2 3.7 16.1 18.7 39.3 3 9 3.6 16.8
Max.
c
1’111. DERIVATIVES O F DIPHENYLAMINE (Continued) 2,4‘-Dinitrodiphenylamine
97
3d
4,4’-Dinitrodiphenylamine
98
3e
N-Kitroso-2,4’-dinitrodlphenglaminek
99 100
3e 3e
N-?iitroso-4,4’-dinitrodiphenylaminek 2,2’,4-Trinitrodiphenylamine
101
3e
2,4,4’-Trinitrodiphenylamine
102
3e
2,4.6-Trinitrodiphenylamine
103
3f
2,2’,4,4’-Tetranitrodiphenylamine
104
3f
2,2’,4.4’,6-P~ntanitrodiphenylamine (acidic solution)
105a lO5b
3f 3f
2,2’,4,4’,6,6’-Hexanitrodiphenylamine (acidic solution) 2,2’,4,4‘,6,6’-Hexanitrodiphenylamine (basic solution)
106
3g
Carbazole
107
3g
9-Methylcarbasole
IX.
405 351 245 402 232 311-312 2160 308-310 370-375 251-255 227-229 365-367 224-225 366-368 233-234 401-402 357-359 219-220 391-393 306-309 376-379 410-412
3 70 299 222 280 216 ca. 255
24.9 1.28 1.8
260-263 293-295 246 216 288-290
2.34 3.5 1.01 1.07 5.40
287-290
4.04
367-371 294
1.32 3.31
320-323 286-289 313-316 288
1.84 1.16 1.83 5.2
...
...
...
...
DERIVATIVES O F CARBAZOLE 336 331 323 305 293 269 256 5 250 5 233.5 343-344 337-338 329-330 305-306 293 273-274 261-262 252 235 312 307 299-300 295 285-286 282-283 262-263 242-243 230 ... 325-326 298-299 280 265 256 250-252 249 238-239 222-2230 . ., 402-405 316-320 300 5 280-281 260-261 256 223-2240 361-365 326-328 305-307 289-290 279-280 252-253 230-231 217-218g 330-335 314-317 306-308 294-296 255-256 233-234 379 358-359 316-317 285 249 236 2230 2210 359-361 326-328 284-285 276-277 265-266 241-242
...
...
108
3g
9- Acetylcarbazole
109
3h
9-Sitrosocarbazole
110
3h
1-Sitrocarbazole
111
3h
3-Sitrocarbazole
112
3i
9-Nitroso-3-nitrocarbazole
113
3i
1,6-DinitrocarbazoIe
114
3i
3.6-Dinitrocarbazole
...
1.46
...
...
...
...
1.17 1.34 4.65 1.19
...
1.46 2.70 3.50 1.65
...
0.44
1.49 1.17 1.04 1.66
3.16 3.36 1.85 1.24 0.51 2.32 1.90 0.94 1.12 0.50 2.80 1.48 2.27 0.61 2.06 1.45 0.84 0.75 2.29 2.47 0.75 2.56 1.92 1.22 1,15 1.41 1.26
I..
2.04 1.41 1.21 1.60
...
3.91 2.16 1.04
...
1.57 1.33 5.41 1.41 1.10 1.08 2.01 1.17 3.06 1.28 1.01 1.67 1.04 2 71
20.6
41.2 6.6
0.8.5
6 2 11.3 16.9 41.0 8.4 10.3 20 9 17.5 39.2 7.6 14.3 9.3 34.8 10.3 14.6 25.2 28.3 10.5 9,8 32.1 10.0 13.4 21.1 22.4 18.2 20.4 30.2
x. DERIVATIVEE O F TRIPHEZIYL.4\IINE 115 116
4a 4a
Triphenylamine 4-Kitrotriphenylamine
117
4a
4,4’-Dinitrotriphenylamine
116 119
4b 4b
1-Kitronaphthalene Tetraphenylhydrasine
120
4b
Phthalidem
121 122
4b 4b
IV, N ’-Diet hyloxanilide
297 394-395 284 255 404-405 231-233
XI.
N , A”-Diphenyloxanilide
250 314 272 247-249 292-296 225
18.5 8.4 1.13 1.03 12.8 1.05
1.04 1.56 3.28 3.20 1.38 2 42
23.6 18.6 8.8 9.1 24.3 13.9
278 269-270 230-233 277 249-250
2.55 2.35 1.56 1.13 5.30
221-222 226-227
1.08 1.22
4.29C 1.64 2.32 8.08 7.78 1.35 2.32 I .85
4.09 20.5 14.5 1.66 1.72 9.9 12.8 21.2
($3)
?dISCELLlNEOUS
333 292-293 258-259 280 273 227 230-231 238-239
...
...
15, 1 8 )
k Spectrum corrected for presence of small amount of corresponding dinitro compound which could not be removed because of lability of nitroaodinitro compound. b I Slit width of spectrophotometer is important if reproducible values are to be obtained a t maxima. Following were used: 293 mp, 0.6 to 0.7 mm.; 256.5 mp, 0.9 to 1.0 mm ’ 233.5 mp 2.0 mm. m Spectrophotdketric data’ in table were determined a t Naval Powder Factory, Indian Head, Xfd.; spectral curve was determined in these laboratories.
1745
V O L U M E 2 3 , NO. 1 2 , D E C E M B E R 1 9 5 1 __ -
Table I.
Spectrophotometric Data for Compounds in Ethanolic Solution (Concluded) Position of Max., hlin., mr mr
Compound NO.
Figure NO.
123
4c
'~',.~",S"-Triphen31isocyanuric acid
124 125 126 127s
4c 40 4d 4d
Diethyl phthalate Dibutyl phthalate N,N'-Diphenylbenzidine Diphenylamine blue (acidic solution)
127h
4d
Diphenylaniine blue (basic solution)
128
4d
2-Methoxynaplithalene ( pnerolin)
129
4e
1,3-DiphenyI-3-ethyltriazene
130
4e
4-Hydroxyazohenzene
131
4e
4-.2minoazobenzene
132
4e
4- (A'-Eths1amino)-azobenzene
133 134 135a
4f 4f 4f
4-Amino-S-ethyl-X-phenylhenzamide 4-(N-Ethylamino)-.\'-ethyl-A'-phenyIbenzamide 4-Nitrocatechol (acidic solution)
135h
4f
4-Sirrocatechol (basic solution)
Name of Compound
259-260 255-256 250 275 275 334-335 596-600 370-375 310-314 273-275 350-360 295-297 328 313-314 281-282 271-272 261-262 227 344-3-16 23 5-2 36 348-351 234-237 386-388 249-255 403-405 255-259 294-296 306-307 343-346 245 423-425 268-270
Dmax __
Dmin.
258 251 246-247 262 262 265 440-450 350-355 288-290 242-244 345-350 254-255 317-319 295-297 278-278 265-266 246-247
1.02 1.23 1.15 1.34 1.34 7.8 78 1.2 1.2 3.3 1.1 3.7 1.53 2.62 1.05 1.20 1.71
258-260
9.2
268-272
8.96
292-296
7.4
332-334 226-228 258-260 265-266 266-268 22 5-226 303-303 249-250
9.3 1.56 1 .83 2.62 4.75 1.38 6.49 1.31
...
...
...
...
...
...
...
C/D of Max. 50 48 59 18.33C 22.fJlC 0.73 0.72 14 2.18 2.36 9 0.94 7.9 10.3 5.2 3.58 3.94 0.224 1.22 1.33 0 80 1.7 0.80 2.28 0.76 2.30 1.67 1.55 2.09 1.98 1.08 2.59
e
X 10-8 of Max.
Literature
0.71 0.74 0.61 1.21 1.21 46.0 76 3.9 25.2 23.4 6.1
59 2.00 1.53 3.04 4.42 4.01 71 18.5 16.9 24.8 11.7 24.6 8.6 29.6 9.8 14.4 17.3 7.4 7.8 14.4 6.0
( 8 , I O , IS, 16, 88)
(4,
19)
-
so*
shown in the eighth column. The last column presents references to the literature These referenceg include only those which are t o be found Ac.h CH~CO-OCH2-S-CH~-S-CHz-N-CH~-X-C'H20-COCH~ in theFourth Decennial Index of Chcrnical Absfracfs COCH, XO? NO? YO? and in subsequent volumes to date No attempt I has been made to cover the older literature because CH~C~-OC€I~--S--C"~-S-CHz--S-CH~--T--CHzO-COCH~ of its frequent inconsistencies and lack of detail. The references that are recorded refer only to H-16 or visible and ultraviolet spectra and t o ethyl alcohol or 95% ethvl alcohol as solvent. Theinterchange 30, $'OCH, SO2 SO2 I I of absolutekthyl alcohol and 95% ethyl alcohol is I not without effect on many ppectra, but the literaCH,CO-~CH~--S--CH,-~-CH,--N--CFI,-~-CI~,O-COCH, ture frequently is careless in defining exactly the so, so1 NO, solvent which was used I I I I n Figures 1 t o 4, the curves, in general, are BSX CH,CO-OCH*-S-CH,-S-CH,-",O-CH*O-COCH, arranged in the numerical order of the conipounds so: so? SO, in Table I. Usually, the entire curve was determined a t one ATS ~o?-o("~-~-.cIT?--?;--cH~-~--cH,o--zo~concentration, which was so chosen that the principal maximum had a n optical density between 0 4 and 1.0. The curve was The saniplei ~~~~, from E Bachmann, then calculated in terms of molecular extinction coefficients. An approximation of the concentration in milligrams per 100 ml. A. T. Blomquist, 3lnivin Carniack, and George F. Kright. of the solution which was used t o determine the curve can be obtained by multiplying C/D of the principal maximum by 0.7. PRESE\T4TION OF DATA Because the nitrates have no distinctive spectrum, their curves The spectrophotometric data and the spectral curves are prehave been omitted. smted in Table I and Figures 1 t o 4. DISCUSSION I n Table I the compounds have been arranged into 11 groups according t o basic structural features. The data for each comof the measurements that ,,ere The accuracy and pound have been arranged in the following way: made by t h e quantitative procedure may be estimated t o be T h e first and second columns contain numbers by means of about 0.5% if we consider the magnitude of the errors inherent in which the spectral curve of t h e compound named in t h e third the weighing, dilution, and spectrophotometric readings. That be identified and located in Figures to 4. The this j s a reasonable estimate is indicated by the fact t h a t for a1)Out names in general follow the recommended nornencalature of 100 measurements distributed among 16 different maxima, the Chrn~ical Abstracts. The fourth column records the Inaxima and the fifth the minima of each spectral curve in the order of mean deviation varied from 0.2 t o 0 5%. The accuracy of the decreasing wave length f o r each compound. The values of remainder of the curve, including the minima and therefore the Dmax for each maximum ivhich is associated with a minivalue of D,,, lDmin,, is probably betlveen and 2%, since mum of shorter wave length are contained in the sixth column. in concentration due t o temperature fluctuations could not be T h e ratio C / D a t maxima is given in the seventh column and t h e corresponding value of the molecular extinction coefficient iq controlled within the instrument during the considerable period KO:
I
I
,
,,
KO,
I
KO?
I
ANALYTICAL CHEMISTRY
1746 20
I:lg(J
32
15
15 24
10
10
16
4
5
5
220
240
260
280
210
240
270
8
220
300
250
280
310
7!k 1 340
410
230
400
253
270
290
/----LJ:‘
I
I
270
20
Fi1.2C
16
20
15 12
8
- 2 0
IO 8
10
4
5
X
I
4
yl
220
250
280
220
310
I I
380
460
I
1
I
260
300
340
300
,
*‘ 240
340
440
220
250
200
220
310
540
250
200
310
I
I
1
16
9 12
6 8 3 4
260
320
380
440
220
Wave Length in M i l l i m i c r o n s
Figure 1.
15
Spectral Curves i n Ethyl Alcohol of Compounds 5 to 18 and 20 to 43
of time which was required t o take the curve. Temperature changes do not influence the results a t the maxima because readings a t those points were taken immediately and rapidly. The roughly quantitative determinations are accurate probably only t o 2 t o 5%. These determinations are less accurate largely because a smaller sample was weighed and because the material was less rigorously purified. However, in instances in which the data were determined first roughly and later quantitatively, the two values differed by only 1 to 2%. Examples of this fact may be seen by comparing the data for compounds 33, 42, 46, 91, and 116 in the present paper with the results reported by Trueblood and hlalmberg ( $ 3 ) after some purification and quantitative determination. Conformity of the behavior of the compounds with that expected from Beer’s law was tested only when the quantitative procedure was used. 90evidence of deviation from Beer’s law was found. Even a cursory examination of the table and the spectral curves will show many obvious correlations between the structure of a compound and its absorption spectrum. The spectrum of a chromophoric group is often modified by variations in structure in a way that is recognizable and predictable. Correlations between structure and spectra are not difficult to find, for example, among the nitramines and the derivatives of urea and carbamic acid, but the correlations which may exist among the nitrophenols, nitroanilines, and nitrodiphenylamines are more complex and obscure, However, it has not seemed desirable here
10
5
230
290
350
210
410
240
170
300
6
4
2
230
250
270
290
W a v e L e n g t h in M i l l i m i c r o n s
F~~~~~2.
spectral curves in Ethyl Alcohol 44 to 79,81,83, and 85
of
Compounds
t o enter into a discussion of all the correlations that may be found. So many compounds have been studied and the structural relationships are so numerous that the possible comparisons would require a length of discussion out of proportion to its merit in pointing out that such relationships exist.
V O L U M E 23, NO. 12, D E C E M B E R 1 9 5 1
1747 ACKhOW LEDGMENT
20
It is a pleasure to acknowledge indebtedness t o Robert B. Corey, under whose supervision the work was carried out, and to Linus Pauling who, as official investigator, made many stimulating suggestions. Some of the spectrophotometric data were determined by Laura L. Fong, Earl Hoerger, Richard hi. Lemmon, Arthur L. LeRosen, Earl W. Malmberg, Rene S. RIills, Floyd W. Preston, Albert M. Soldate, Thomas D. Waugh, and M. Kent Wilson. The figures were drawn by Maryellin Reinecke, Betty hl. Bell, and Doris Hall.
24
15
15 18
10
m
b -
12
10
6
5
5
X
220
240
2W
220
2SO
380
300
460
c
20
LITERATURE CITED 15
10
5
280
260 320 380 440 500
L_
-03 0
-0
0)
11'
40
2
440
360
,
I
520
I
32
30
30
24
20
20
16
10
10
8
220
260
300
340
240
320
400
480
L ,
220
300
380
460
Wave L e n g t h i n M i l l i m i c r o n s Figure 3.
Spectral Curves in Ethyl Alcohol of Compounds 80, 82, 84, and 86 to 114
20
15
10
L., Trueblood, K. N., Landed, J. D., and Hoerger, E., I b i d . , 41,2818 (1949). (20) Schroeder, W. A., and Wilcox, P. E., J . Am. Chem. Soc., 72, 3814 (1950).
5
0
220
300
380
460
380
540
700
220
280
340
(21) Ibid., P. 4309. (22) Schroeder, W. A., Wilson, M. K., Green, C., m'ilcox, P. E., Mills, R. S., and Trueblood, K. N., Znd. Eng. Chem., 42, 539 (1950). (23) Trueblood, K. N., and Malmberg, E. W., J . Am. Chem. Sac., 72, 4112 (1950). (24) Wilcox, P. E., and Schroeder, W. A., J. Org. Chem., 15, 944 (1950). (25) Wright, G. F., and coworkers, Can. J . Research, 27B, 218, 462, 469,489,503,520 (1949). (26) Zelinski, R. P., and Bonner, W. A., J . Am. Chem. Soc., 71, 1791 (1949).
400
0
c
0 0
E X
60
w
L
-03
-$
(1) Bachmann, W. E., and Sheehan, J. C., J . Am. Chem. Sac., 71, 1842 (1949). (2) Brode, W. R., and Cheyney, LaV. E., J . OTQ. Chem., 6, 341 (1941). (3) Cary, H. H., and Beckman, A. O., J . Optical Sac. Am., 31, 683 (1942). (4) Earl, J. C., and Robson, A. O., Australzan Chem. Inst. J . and Proc., 6 , 268 (1939). (5) Hertel, E., 2.Elektrochem., 47,813 (1941). (6) Hertel, E., and Lebok, E., 2.physik. Chem., B47, 315 (1940). (7) Hertel, E., and Schinzel, M., 2. Elektrochem., 45, 401 (1939). (8) Jones, R. N., and Thorn, G. D., C a n . J . Research, 27B, 828 (1949). (9) Kumler, W. D., J . Am. Chem. Sac., 68, 1184 (1946). (10) Martynoff, M., Bull. sac. chtm. France, 1947, 1018. (11) Masaki, K., B u l l . Chem. soc. J a v- a n .. 11.. 712 (1936). (12) Mohler, H., Helv. Chim. A c t a , 26,121 (1943). (13) Pongratz, A., hlarkgraf, G., and Maver-Pitsch. E.,Ber., 71B, 1287 (1938). (14) Ramart-Lucas, P., and Grunea, M., Compt. rend., 211, 120 (1940). (15) Ramart-Lucas, P., Grunes, hl., and Martynoff, M., B u l l . sac. chim., 12,814 (1945). (16) Robertson, W.W., and Matsen, F. A., J . Am. Chem. Soc., 72, 1543 (1950). (17) Schroeder, W. A., Ann. N . Y . Acad. Sci., 49, 204 (1948). (18) Schroeder W. A., Keilin, B., and Lemmon, R . M., I n d . Eng. Chem., 43, 939 (1951). (19) Sohroeder, W. A., Malmberg, E. W.,Fong, L.
45
30
0
15
RECEIVED February 12, 1951. 220
Wave Figure 4.
220
320
420
520
230
330
430
530
L e n g t h in MiII.imicrons
Spectral Curves in Ethyl Alcohol of Compounds 115 to 135
Contribution 1526 from the Gates and Crellin Laboratories of Chemistry. This paper is based in whole on work done for the OEce of Scientific Research and Development under Contracts OEMsr-702 and OEMsr-881 and for the Kavy Department, Bureau of Ordnance, under Contract NOrd-9652 with the' California Institute' of Technology.
