Absorption Spectra of Chlorophylls a and b at Room and Liquid Nitrogen Temperatures

Abstract

THE absorption spectra of ether solutions of chlorophylls a and b, prepared by the method described earlier1, were photographed at the temperature of liquid nitrogen. A Steinheil spectrograph and panchromatic plates were used for the spectral region 4100–6700 A. Pyrex glass absorption cells with internal thickness of 1 mm. contained the solutions. Four plane quartz windows in the walls of the Dewar vessel permitted parallel light to pass from the Mazda source through the liquid nitrogen bath and the solid solution of chlorophyll in ether, to the spectrograph slit. The slit width was 0.02 mm. The photographs were taken as soon as possible after freezing the solutions because the development of cracks in the solid ether solution caused it to become rather opaque in two hours.