316 - Spectroscopic study of chlorophyll and pheophytin adsorbed on the electrode
1980; Elsevier BV; Volume: 7; Issue: 2 Linguagem: Inglês
10.1016/0302-4598(80)87007-3
ISSN1872-8049
AutoresМ. Р. Тарасевич, L. A. Khanova, G.Yu. Borover,
Tópico(s)Photosynthetic Processes and Mechanisms
ResumoPheophytin as well as chlorophyll is irreversibly adsorbed on a gold amalgam electrode. It can be reduced almost reversibly with the consumption of one proton per one electron. The reflectance spectra of adsorbed chlorophyll and pheophytin were obtained. The chlorophyll spectrum at low surface concentrations is analogous to the spectrum in solution. In the surface condensation region a long-wave shift of the red maximum was observed that is due to the aggregation of adsorbed chlorophyll. The pheophytin spectrum possesses the features characteristic both of keto- and enol-forms. The extinction coefficient for adsorbed pigments is by 2–3 orders of magnitude higher than in solution. The effect may be supposed to be connected with a strong interaction of the porphyrin ring π-electrons with the metal.
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