SPECTROSCOPIC FORMS OF DIVINYLPROTOCHLOROPHYLLIDE IN SOLID FILMS

Solid films were prepared from diethyl ether solutions of divinylprotochlorophyllide on glass surfaces and then treated with vapours of acetone. The transformation of the films and the appearance of different spectroscopic forms of divinylprotochlorophyllide were observed by absorption spectroscopy. Computer analysis allowed resolution of the absorption spectra into forms with maxima in the red region at 628-630, 635, 644, 650, 655, 665 and 676 nm. These Gaussian peak positions are very similar to those of protochlorophyllide species described in etiolated leaves (Litvin, F.F. and Stadnitshuk, I.N. (1980) Fiz. Rast. (Moscow) 27, 1024-1030, in Russian) or of protochlorophyll forms found in solid films (Böddi, B., Rákász, É. and Láng, F. (1983) Photobiochem. Photobiophys. 5, 27-33). This indicates a similarity in the electronic structures of these pigment aggregates and shows that the additional vinyl group in the divinylprotochlorophyllide does not modify this structure remarkably. © 1990.