346 



R. Lemberg, p. Clezy and J. Barrett 



compared with ether, e.g. shifts all band positions from 2-6 m/t towards 

 the red. 



Table 1. Absorption spectra of porphyrin a, cryptoporphyrin a 



AND CHLOROCRUOROPORPHYRIN 



A in m/i 



in 

 chloroform 



Porphyrin a 

 Cryptoporphyrin a 

 Chlorocruoroporphyrin 



I 



646 



642-5 



644-5 



II 



584-5 



584 



585 



III 



563-5 



559 



560 



IV 



520 

 519 



520 



Secondly, while chlorocruoroporphyrin has a rhodotype spectrum, with 

 the ratio of bands III/IV 1-3-1-4, porphyrin a has an oxorhodo type spectrum 



670 



480 



670 



Fig. 1 . Types of porphyrin spectra. 



460 



with both bands II and III higher than IV and the ratio III/IV as high as 

 2-40-2-45 (Fig. 1). The order of strength of the rhodofying influence of 

 side chains is 



• CHO ^ ring-CO > • CH : CH • COMq > • COMq 

 ^ •COR> -CHrNOHr^ -CHiCHo 



