426 



PHOTOMECHANICAL CONSIDERATIONS 



TABLE 1. 



Characteristics of absorption spectra 



Spectrum I is for the protein-chlorophyll-770 complex from Cps. ethylicum 

 dissolved in 0.2 M NaCl and .01 M Tris, pH 8.0; spectrum II isfor chlorophyll- 

 770 dissolved in ether after purification by sugar chromatography; and spectrum 

 III is for bacteriochlorophyll from CJiroinatiiii}! dissolved in ether after sugar 

 chromatography. Peak positions (Xn) are given in mfi, and the peak height ratios 

 (rn) are relative to the maximum red absorbance. 



This absorption band was observed before sugar chromatography, but could 

 not be seen after sugar chromatography because of the UV absorbing material 

 in Skellysolve B which is also eluted from the sugar by ether. 



■O T3 



1.0 



1.2 



1.3 



1.4 



1.5 



7(a-l)- 



1.00 0.95 0.90 0.85 0.80 

 Xifi)" 



0.75 



0.70 



Fig. 3. Fluorescence emission spectra (dQ/dl^) at 294° K ( ) and 77° K 



( ) of the protein-chlor()phyll-770 complex from Cps. etiiyli cum caused 



by excitation at 366 m/n, and the far red absorption ( • ) normalized 



to the main fluorescence peak at 294° K. 



