CHLOROPHYLL 



233 



CH 3 C 



C 2 H 5' C 



CH 



CHo C 







CH = CH 



I I 



C C 



C C = 



CH, CH 3 



Aetiophyllin C^H^N^g 



C 'C 2 Hg 



C-CH, 



The Action of Acids. 



Acids, especially oxalic acid, remove magnesium from all 

 derivatives containing this element, replacing it by two atoms 

 of hydrogen without altering the rest of the molecule. 



Thus chlorophyll a and b give by removal of Mg the com- 

 pounds 



/COOCH, 



'1 OM f 



and 



COOCH 



Phaeophytin a 



Phaeophytin b 



respectively, while chlorophyllin a gives phytochlorin / and 

 -, C 32 H 32 ON 4 (COOH) 2 . On the other hand, glauco and 

 rhodophyllin by removal of magnesium give glauco and 

 rhodoporphyrin C 31 H 34 N 4 (COOH) 2 , while pyrrophyllin yields 

 pyrroporphyrin C 31 H 35 N 4 (COOH). By removing the last car- 

 boxyl from the latter compound a substance aetioporphyrin 

 C 31 H 36 N 4 is obtained, which is the magnesium free analogue 

 of aetiophyllin C 31 H 84 N 4 Mg. 



CRYSTALLINE AND AMORPHOUS CHLOROPHYLL. 



The physical constants of these substances as determined 

 by Willstatter and his pupils are as follows : 



