4384
H. HARRY SZMANT AND J. AT, DIXON [CONTRIBUTION FROM
THE
Vol. 78
DEPARTMENT OF CHEMISTRY, DUQUESNE UNIVERSITY]
The Ultraviolet Spectra of Some Diary1 Sulfones1 BY H. HARRY SZMANT AND
JAMES
M. DIXOX
RECEIVEDMARCH7, 1956 The spectra of a series of substituted p-phenylsulfonylphenols are presented as well as evidence which suggests a high double-bond character of the sulfur-oxygen bonds in P-(4-nitrophenylsulfonyl)-phenol.
During the investigation of the relative acidities of a series of @-substituted 4phenylsulfonylphenols,’ it was noticed that only one of the phenols, namely, @-(4-nitrophenylsulfonyl)-phenol (I),gave a yellow solution in an alkaline medium. Since the unique behavior of this compound is caused by the presence of a nitro substituent far removed from the site of the anion formation, i t was of interest to investigate the ultraviolet spectra of a number of phcnolic sulfones. Experimental The preparation and physical properties of the phenols were reported previous1y.l The ultraviolet spectra were determined by means of a Beckman DU spectrophotometer using solutions in 95% ethanol or in 0.01 molar aqueous sodium hydroxide. The spectral data are summarized in Table I .
TABLE I
ULTRAVIOLET SPECTRA OF P-(4-R-CsH4SOy)CsHdOH R H CIli F CI Br
Max. (mp) 256 256 255 262 262
I
266
CHaO 260 235 H2N 285 24Zb OzN 285 242
I n 95% Ethanol e X Min. e X (mp) 10-4 10-4 1.25 1.62 234 0.14 1.88 1 . 7 0 240 0.28 1.43 244 0.30 1.68
2.10 1.25 1.81 0.92 1.08 1.85
240
1.0
253
0.39
265
0.99
In 0.01 M PiaOH e X Min. e X
Max.
(mp)
290 290 290 293 295 235 297 3OSu 250 263’ 290 242 295 256b 345’ 265
10-4 1.74 1.88 2.65 2.12 1.66 1.30 2.32 2.03 1.60 1.10 2.30 1.37 2.36 1.49 0.65 2.22
(mp)
10-4
250 240 246 254
0.19 0.32 0.42 0.42
264
1.01
254
0.52
265
1.32
305
0.58
MAXIMAOF
TABLEI1 SPECTRA OF p-SUBSTITUTED PHENOLS AND PHENOLATE Ioxs
R
Ref
H NHI +
Phenola
Phenolate5
Akb
6
210 5 235 24 5 6 218 5 3 223 218 25 CH,SOzc 6 225 244 19 c1 (CHdzS+’ 3 226 218 5 (-7 5 ) d CH,SOz 4 239 269 30 (CHd?S 3 242 269 27 4-H?NCsHISO2 2-13 256 23 co2 6 245 280 35 CO?H 6 255 e’’ 255-266 290-297 31-35 4-R’CeH,SO, 49 5 CHsCO 6 275 324 5 HCO 6 283 5 330 46 5 4-OyXCsHdS02 285 315O 608 0,s 6 317 5 402 5 85 Displacement of maximum in phenoa Maxima in mp. late ion (mp). Meta substituent. See reference 3 . * This work. f R’ groups are methyl, F, C1, Br, I , hfethoxyl. Center of broad band. +
tion of the nature of the R substituent. Application of the previously postulated hypothesis’ permits the prediction that the relative double bond character of the sulfur-oxygen bonds increases in the series CHaSOz
a Inflections. * T h i s band is considered due to the absorption of the p-hydroxyphenylsulfonyl chromophore since it is relatively unchanged when the spectrum is taken in the presence of 0.1 M perchloric acid (244 mp, E 9,900). The longer wave length band is hypsochromically displaced in this acid medium t o 275 mp, E 5,000. Center of broad band.
THE
< p-HgNCeH4SOz
