THE OXIDATION OF PHENOL: THE EFFECT OF SOME 



FORMS OF LIGHT AND OF ACTIVE OXYGEN 



UPON PHENOL AND ANISOLE. 



By H. D. GiBBS. 



(From the Laboratory for the Iiwestigatimi of Foods and Drugs, 

 Burea/w of Science, Manila, P. I. ) 



I have shown ^ that neither pure phenol, moist crystals, nor a solution 

 of the crystals in water are affected by the intense sunlight of this 

 locality when exposed in sealed glass tubes in atmospheres of nitrogen, 

 hydrogen, or carbon dioxide. 



Kohn and Fryer ' have exposed both pure phenol crystals and moist phenol in 

 vacuo and found the light to have no effect. From these experiments they, 

 and Richardson,' conclude that the reactions responsible for the red coloration of 

 phenol are due to hydrogen peroxide oxidation and that the presence of water, 

 oxygen, and sunlight are all necessary factors, the absence of any one of which will 

 prevent the reaction. 



These writers, as I have shown,* are correct in their opinion that the cause 

 of the red coloration is oxidation and I have isolated the products to be expected 

 from such a reaction, namely, quinone and catechol. Another substance which is 

 probably formed during the reaction is quinol and the presence of the condensa- 

 tion product phenoquinone is extremely probable. 



Kohn and Fryer state ° "since the coloration is always accompanied by the 

 absorption of moisture, the presence of moisture is most probably intimately as- 

 sociated with the formation of the color" and " "in the absence of moisture no 

 coloration takes place." 



Since writing the first article '' "The Compounds which Cause the Eed 

 Color in Phenol," this phase of the question has been investigated and 

 I find that these statements are not in accord with the facts. It is not 

 surprising that Kohn and Fryer were led into this error, for the character 

 of the sunlight available to them and the atmospheric conditions in their 



'■This Journal, Sec. A, (1908), 3, 361. 



-Journ. Soc. Ghem. Ind. (1893), 12, 111. 



= Ibid, (1893), 12, 415. 



* Loe. cit. 



'hoc. cit. 110. 



'hoc. dt.. 111. 



'' Loc. cit. 



133 



