742 



FLUORESCENCE OF PIGMENTS IN VITRO 



CHAP. 23 



(1943) by means of a photoelectric spectrophotometer. The maximum of 

 the first emission band Hes, in this figure, at 664.5 mn for chlorophyll a and 



Chlorophyll a in ether 

 excitation by Hg line 365 m/i) 



Chlorophyll a 

 Chlorophyll 6 



Chlorophyll a 

 Chlorophyll b 



dissolved in 

 carbon disulfide 

 (excited by 

 carbon arc) 



ojirtcD (0 



oo«3r- 1^ 



(MOID 00 



l^f^ (O If) 



to 



o 



Wove length, A. 



Helium 



Etioporphyrin 

 Phylloerythrin 

 Pheophorbide a 

 Pheophorbide b 

 Chlorophyll a 



Chlorophyll b 

 Helium 



pyridine 



ethyl ether 



Fig. 23. IB. Fluorescence spectra of chlorophyll and some related compounds 

 on infrared-sensitive plates (after Dhere and Raffy 1935). Top: (2) Chlorophyll 

 a in ether (excited by X36-5 m/x); (4) and (7) chlorophyll a in CS2 (e.xcited by car- 

 bon arc); (5) and (8) chlorophyll 6 in CSo (excited by carbon arc). Bottom: (2) 

 etioporphyrin in pyridine; (3) phylloerj^hrin in pyi-idine; (4) pheophorbide a in 

 ether; (5) pheophorbide b in ether; (6) chlorophyll a in ether; (7) chlorophyll b in 

 ether. 



648.5 m/i for chlorophyll 6— only very slightly on the long-wave side of 

 the maxima of the corresponding absorption bands (c/. Table 23. IC). The 



