123 



ergy relations of that system which declared itself in the decrease 

 of the excitation energy of the dye. Such a shift in energy values 

 may very well cause trouble in cells where energy levels can be 

 expected to be tuned carefully. Such a lowering of excitation en- 

 ergies for instance, may prevent the excited molecule from going 

 from the singlet into the triplet state, the energy le\'el of which is 

 usually somewhat lower. So if the energy of the singlet excitation 

 is decreased, the energy difference between the two states may 

 become insufficient to allow the transition. 



We have found 2,4-dichlorophenol to be a strong quencher of 

 various excitations and so it was surprising to find 2,4D devoid of 

 this action. On the other hand, 2,4D showed other activities not 

 possessed by 2,4-dichlorophenol. One of these consisted of de- 

 creasing the lifetime of triplet excitation. As has been shown be- 

 fore, glutathione prolongs the lifetime of rhodamin from 10"^ 

 seconds into the dimension of seconds. While a pure rhodamin 

 solution, in the frozen state, showed a very poor phosphorescence 

 in the phosphoroscope, in the presence of 0.01 M glutathione it 

 showed a strong phosphorescence even in the slow moving phos- 

 phoroscope and showed a strong afterglow. Addition of 10"^ M 

 2,4D completely abolished this long life phosphorescence. In its 

 presence the tube showed even in the fast moving phosphoroscope 

 no increased phosphorescence; 2,4D thus completely eliminates 

 the long life excitation caused by 0.01 M glutathione or 2% glu- 

 cose. Since even ten times less 2,4D had a strong effect, the change 

 could not be explained by an interaction of 2,4D with glutathione 

 and the drug must have acted on the excitation, decreasing greatly 

 the stability of the triplet state. If such states are important for the 

 energy supply of the cell because of their long lifetime than it is 

 easy to see that 2,4D has to cause a profound disturbance in en- 

 ergization. The experiments showed that 2,4D could eliminate the 

 long-life phosphorescence even in lO"* M concentration; 2 X 10"* 

 M also quenched the yellow phosphorescence of quinidine. 



Another additional observation also indicated a labilization of 



