EMIL H. WHITE 



193 



The stoichiomctiy ol the reaction is as shown in Fig. 9. One 

 molecule ol the dianion reacts with one molecule of oxygen to form 

 one molecule of the dianion of aminophthalic acid and one molecule 

 of nitrogen. 



The first step in the reaction must involve the dianion and oxygen, 

 since no light is observed when the monoanion is exposed to oxygen, 

 and the dianion luulergoes no reaction in the absence of oxygen. 

 A possible intermediate is the hyperoxide ion shown in Fig. 9. A 

 closely related reaction of Grignard reagents has been reported 

 recently (28) . 



RrM^X+ + O. -> /?— O— 0-MgA'+ 



Unlike the reaction in water, the chemiluminescent reaction in di- 

 methyl sulfoxide is not noticeably affected by cyanide ion or by the 

 transition metals. A radical decomposition path for the hyperoxide 

 is, therefore, unlikely. An intramolecular decomposition is probably 

 involved, since it has been found that peroxide ion is not an inter- 

 mediate; that is, the oxygen is eventually reduced by four electrons 

 without passing through Og^. Very little more can be said about 

 the intramolecidar reaction at the present time. 



The luminol chemiluminescence in dimethyl sulfoxide has a peak 

 emission at 480 ni/i,, a wavelength corresponding to about 60 kcal. per 

 einstein. Approximate calculations of the energy available from the 



several 



steps 



■^ N2 + 



NH^ O 



Fig. 10. .V possible path for the formation of nitrogen. 



