56 O- OSTER 



In his woik, is the reduction process of chlorophyll a one-electron or a two-electron 

 process? Does anybody know? 



Rabinowitch {remarks added in -proof): Krasnovskii postulates reduction to a 

 radical (in ionized and neutral form). Linschitz et al, however, found in this sys- 

 tem no paramagnetic resonance effects characteristic of free radicals. 



Wassink : Have you tried hydrogen gas as a reducing agent for your photoreduc- 

 tions? 



Oster-.No. 



Linschitz: Did you say that the chlorophyllide showed no color change but 

 that it was reduced? 



Oster: I said that I could see no color change, and I would like to ask Dr. 

 GafTron if he saw a color change. 



Gaffron : No, but this was in the presence of oxygen. 



Oster : In the absence of oxygen I still did not see a color change. I just looked 

 for it by eye. 



References 



1. Rabinowitch, E., J. Chem. Phys., 8, 551 (1940). 



2. Oster, G., and Wotherspoon, N., /. Chem. Phys., 22, 157 (1954). 



3. (a) Nickerson, W. J., and Merkel, J. R., Proc. Natl. Acad. Sci. (U.S.), 39, 901 



(1953); (b) Merkel, J. R., and Nickerson, W. J., Biochem. et Biophys. 

 Ac/a, /^, 303 (1954). 



4. Oster, G., and Wotherspoon, N., to be published. 



5. Fujimori, E., J. Chem. Sac. Japan, Pure Chem. Sect., 75, 116 (1954). 



6. Oster, G., Nature, 173, 300 (1954). 



7. Oster, G. K., Oster, G., and Prati, G., J. Am. Chem. Sac, 79, 595 (1957). 



8. Oster, G., and Adelman, A. H., J. Am. Chem. Soc, 78, 913 (1956). 



9. Adelman, A. H., and Oster, G., /. Am. Chem. Soc, 78, 3977 (1956). 



10. Gaffron, H., Biochem. Z., 264, 251 (1933). See also Rabinowitch, E., in Photo- 



synthesis, Chapter 18, Interscience, New York, 1945, and Weiss, J., Sym- 

 posium Soc. Dyers and Colourists, p. 135, Manchester, 1949. 



11. Knight, J. D., and Livingston, R., /. Phtjs. & Colloid Chem., 64, 703 (1950); 



Livingston, R., Record Chem. Progr. {Kresge-Hooker Sci. Lib.), 16, 13 

 (1955). 



12. Oster, G., /. Polymer Sci., 16, 235 (1955). 



13. Oster, G., and Nishijima, Y., J. Am. Chem. Soc, 78, 1581 (1956). 



14. Oster, G., Trans. Faraday Soc, 47, 660 (1951). 



15. Oster, G.. and Bellin, J., J. Am. Chem. Soc, 79, 294 (1957). 



