The Electrodeposition of Films of Chlorophyll-a Microcrystals and Their Spectroscopic Properties

Publisher Website
Google Scholar
Abstract
It is found that a suspension of microcrystals of chlorophyll-a (Chl-a) in a nonpolar medium may be electrodeposited as a film on a cathode. Spectroscopic properties of the film indicate that it is quite uniform and consists of randomly oriented microcrystals. Upon heating, the electrodeposited microcrystalline film is transformed to an alternate form of aggregated Chl-a. This new film appears to resemble very closely the Chl-a films previously obtained in monolayer work. Either film may be dissolved into monomer form and it is seen how Chl-a monomer is conserved during the complete process proceeding from electrodeposition to thermal conversion and the final dissolution. Furthermore, it is found how the oscillator strength over the red-visible region is the same for the dissolved monomer and the second type of film. The simple excited state resonance model for the spectrum of the latter is thus supported. The oscillator strength of the microcrystal film, by contrast, is about 40% greater. Such electrodeposited films are quite stable at room temperature and can serve well as samples in a variety of photoelectric studies.