104 



RADIATION BIOLOGY 



4,8 



BAND I 



Fig. 2-20. Theoretical and observed vector directions of porphyrin moments at 

 different positions of substitution. 



mined, as the central-nitrogen-atom direction in the Erdman-Corwin 

 model is fixed by symmetry) ; and 



4. From all these data, the symmetry of the band I wave function and 

 of the band III wave function with respect to the H-H axis. 



The determination of point 4 would not be so straightforward as the 

 others, because the labile central hydrogen atoms may very well be on 

 the I and III rings of porphin in one compound and on the II and IV 



