406 The Philippine Journal of Science mz 



The sulphuric acid solution fluoresces green, and also gives a 

 ngle band that heads 

 remarkable persistence. 



single band that heads nearer the red at -r- = 3120, and shows 



A 



PHTHALIMIDENE 



C=H 2 

 C 6 H 4 <^ ^>NH 

 C=0 



Phthalimidene was prepared from phthalimide 4 and purified 

 similarly to the preceding compound. The alcohol solution gives 



two absorption bands, a very narrow one heading at - = 3600 



1 

 and a broader one slightly more refrangible at - = 3720. The 



A 



spectrum is not altered by the addition of one equivalent of so- 

 dium ethoxide (fig. 6) . 



The sulphuric acid solution also gives two bands, a shallow one 



1 '1 



at r = 3520 and a well-marked one at - = 4040. 



A A 



NITROSOPHTHALIMIDENE 

 C=H 2 



C 6 H 4 <^ ^>NNO 

 C=0 



Nitrosophthalimidene, prepared from phthalimide by the ac- 

 tion of nitrous acid, 4 was obtained in long yellow needles after 

 recrystallization from dilute alcohol. The absorption spectrum 

 in alcohol is complicated and contains three bands. The color 



band heading at - = 2320 is very well marked and of consider- 



1 

 able persistence. A shallow band shows at -r = 2940, and the 



third heads at \ = 3820 (fig. 7) . 



The addition of one equivalent of sodium ethoxide produces a 

 decided change in color, and shifts the bands to -r = 2160, 2940, 



and 3480. The intermediate band now appears at much greater 

 dilution, and is more persistent. 



* Graebe, loc. cit. 



