VIII. A, 6 



Pratt: Phthalides and Related Compounds 



405 



The addition of alkali causes a broadening of the band and a 

 reduction in persistence, until, in the presence of 5 equivalents 



3.8 



3.6 



I 3.4 



* 8.2 



* 3.0 



s 



I 2.8 



2.6 



I 2.4 



Z.8 



Oscillation frequency. 



3000 32 34 36 



4000 



1 2 





' 

















































1 

























































































































3 \ 





















2.Z 



2.0 



1.8 



Fig. 6. Curve 1. Phthalimide in alcohol. Curve 2. Phthalimide in sulphuric acid. 

 Curve 3. Phthalimide in alcohol + 5 equivalents of sodium ethoxide. 



of sodium ethoxide, the general absorption closely approaches 

 the visible region of the spectrum. The band is broad and 

 shallow, but shows no change in the position of its head. 



