Short-Wavelength Absorbing Complexes of Chlorophyll a in Micellar Solution of Cationic Detergents

Abstract

Micellar aggregates have been prepared from chlorophyll a. Whereas most detergents including non-ionic, zwitterionic and anionic ones, produce aggregates with long-wavelength shifted and enhanced QY absorption, the cationic detergents hexadecyl-trimethylammoniumbromide and hexadecyl-pyridiniumchloride produce complexes with opposite traits: The QY absorption is shifted to shorter wavelengths, and it is hypochromic. The optical activity is increased as in the long-wavelength shifted complexes, but the cd bands are non-conservative and coincide with the absorption maxima. The complexes are most likely small aggregates o f chlorophyll with a changed geometry as compared to the “standard™ ones. © 1990, Walter de Gruyter. All rights reserved.