ABSOLUTE ASYMMETRIC SYNTHESIS. I. ON THE MECHANISM OF THEPHOTOCHEMICAL ABSOLUTE ASYMMETRIC SYNTHESIS OF HELICENES WITH CIRCULARLYPOLARIZED LIGHT. . WAVELENGTH DEPENDENCE OF THE OPTICAL YIELD OFOCTAHELICENE. (open access)

ABSOLUTE ASYMMETRIC SYNTHESIS. I. ON THE MECHANISM OF THEPHOTOCHEMICAL ABSOLUTE ASYMMETRIC SYNTHESIS OF HELICENES WITH CIRCULARLYPOLARIZED LIGHT. . WAVELENGTH DEPENDENCE OF THE OPTICAL YIELD OFOCTAHELICENE.

The synthesis of nonracemic yields of hexa-, hepta-, octa-, and nonhelicene with circular light was observed, and the structural and wavelength dependence of the induced optical yields was examined. The results obtained, together with a detailed consideration of the mechanism of helicene synthesis from the parent diarylolefins, indicate that the induced optical activity is due to selective reaction of enantiomeric conformations of the parent cis diarylolefins by circular light.
Date: May 1, 1971
Creator: Bernstein, William J.; Calvin, Melvin & Buchardt, Ole.
System: The UNT Digital Library
SPECTROSCOPIC INVESTIGATION OF THE INHIBITORY EFFECT OF FATTYACIDS ON PHOTOSYNTHETIC SYSTEMS (open access)

SPECTROSCOPIC INVESTIGATION OF THE INHIBITORY EFFECT OF FATTYACIDS ON PHOTOSYNTHETIC SYSTEMS

Fatty acids have a reversible inhibitory effect on respiration and on photosynthetic action. They investigated the influence of octanoic acid on the photosynthetic bacteria Rhodopseudomonas spheroids R-26. From the spectroscopic data they conclude that a less efficient energy transfer and decoupling of the light harvesting pigment system from the energy converting reaction center is responsible for the inhibitory effect.
Date: May 1, 1971
Creator: Steffea, Hans & Calvin, Melvin.
System: The UNT Digital Library