NOTES
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Preparation of o-Nitrosophenols from Benzene or Other Aromatic Hydrocarbons at Room Temperature BY OSKARBAUDISCH
Vol. 63
lived nitrosyl radical NOH is captured and brought into chemical reaction with inserted ethylene groupings. (1) Science, vol. No. 2389, 336 (1940).
STATERESEARCH INSTITUTE OF THE SARATOCA SPA N. Y. RECEIVED SARATOGA SPRINGS, OCTOBER 28, 1940
Sodium pentacyano-ammine-ferroate (ammin salt) (2 g.) was dissolved in 100 cc. distilled water and 25 cc. of benzene as well as 50 cc. of ligroin added and the mixture cooled with ice water. Raman Spectrum of an Aqueous Solution of Now 2 g. of NHZOH-HCl is dissolved in the Potassium Cyanate‘ solution (color changes from brown to grass BY FORREST F. CLEVELAND green) and 4 cc. of Merck superoxol added. (Color In a recent investigation of the infrared abchanges from grass green to deep brownishsorption spectrum of a saturated aqueous soluviolet.) Already, a few minutes after adding the tion of potassium cyanate, Williams2 found inhydrogen peroxide o-nitrosophenol can be detense bands for the freshly prepared solution a t tected in the ligroin layer. After shaking violently 870 and 2170 ern.-' which were attributed to funfor one hour, the color of the benzene-ligroin layer damentals vl and vg, respectively, of the linear is deep green, due to the formation of larger group. After the solution had stood amounts of o-nitrosophenol. The green benzene- O-C=Nfor several days, additional absorption bands were ligroin part (aqueous part P) is now separated, observed a t 1350, 1690 and 2860 ern.-'. These washed with ice water and shaken with dilute bands were attributed to absorption by amcopper sulfate solution. A deep red water soluble monium and carbonate groups formed by hydrolyo-nitrosophenol copper salt (Sol. C) is formed sis. The present note is a report of a Raman while the benzene-ligroin becomes entirely colorspectra study undertaken to supplement the inless and is used for further extraction of the frared data. aqueous part P. After shaking for one or two Experimental hours the deep green benzene-ligroin is again separated and o-nitrosophenol converted into Ten cc. of an approximately saturated solution the red copper salt (Sol. C). The aqueous part of “c. P. Baker’s Analyzed” potassium cyanate is now diluted with 100 cc. of water and several was prepared and a one hour exposure made imtimes extracted with ligroin until the ligroin is mediately. Following this a polarization speconly pale green in color. The copper salt solu- trogram was made and the solution stored in a tions C, C1,etc., are united, and in presence of closed test-tube. One hour exposures were made petrol ether acidified with hydrochloric acid. The on successive days over a ten day period and deep green petrol ether is washed with ice water finally a polarization spectrogram of the aged free from excess acid. It keeps protected from solution was made. light in the cold for weeks unchanged. Details regarding the experimental technique If benzene is replaced by toluene, ethylben- have been given in previous papers3 The zene, xylene, phenylacetylene, chloro- or bromo- 4358 8.mercury line was used for excitation of the benzene, similar results are obtained but with spectra. varying yields. Results Sodium pentacyano-ammine ferroate can, howThe results are summarized in Table I. Colever, not be replaced by ordinary ionized iron umns one, two and three give the Raman dissalts. In repeating the described experiment placements in cm.-’, estimated intensities and dewith ferrous sulfate (2 g.) only traces of o-nitropolarization factors for lines in the spectrum of the sophenol are formed. fresh solution, while columns four, five and six In the complex sodium pentacyano-aquogive the corresponding data for the aged solution. ferroate, which is formed from the ammin salt in (1) Presented at the Seattle, Washington meeting of the American the acid medium, the sixth free valence of the Physical Society, June 21, 1940. ferrous central atom shows an exceptionally (2) Dudley Williams, THIS JOURNAL, 62, 2442 (1940). Forrest F. Cleveland and M. J. Murray, J . Chcm. Phys., 7, great chemical affinity to NO compounds. This 396(3)(1939); M.J. Murray and Forrest F. Cleveland, THIS JOURNAL, fact seems to be the main reason that the short- 61, 3546 (1939).
