THE PHILIPPINE 



Journal of Science 



A. Chemical and Geological Sciences 

 AND the Industries 



Vol. IX APRIL, 1914 No. 2 



THE ABSORPTION SPECTRA OF VARIOUS PHTHALIDES AND 

 RELATED COMPOUNDS, II 



By David S. Pratt and Harvey C. Brill 

 (From the Laboratory of Organic Chemistry, Bureau of Science, 



Manila, P. I.) 



Six text figures 



The absorption spectra of phthalide and some of its derivatives 

 both in alcohol and in concentrated sulphuric acid solutions were 

 described in a previous paper.^ It was shown that an intimate 

 connection exists between the absorption bands given by these 

 compounds and the character of substituting groups in the side 

 ring or chain. When radicals are present that possess high 

 residual affinities, the spectra deviate from the phthalic acid 

 type to a greater or less extent, depending upon the degree 

 of activity possessed by the substituting group. Two distinct 

 phases are encountered in progressively increasing the activity 

 of the nonbenzene portion of the molecule. The first tendency 

 is to displace the absorption band and increase general absorp- 

 tion. This is followed by an actual splitting of the band into 

 two or more bands, one of which, under ordinary circumstances, 

 occurs in the region characteristic of simple disubstituted 

 benzene derivatives. It was also shown that sulphuric acid 

 with high residual affinity acting as a solvent for phthalides 

 transferred energy to the side portion of the molecule with similar 



'Pratt, D. S., This Journal, Sec. A (1913), 8, 399. 



126870 105 



