[Fluorescence quenching of chlorophyll and its analogs by oxidants]

The quenching of the fluorescence of chlorophyll, Zn- and Cd-pheophytinates, Mg-, Zn-, Cd-, Al-, Ga-, In-, Hf-tetraphenylporphine in different solvents with chlorinanyl, p-benzoquinone and m-dinitrobenzole has been studied. It is concluded from the dependence of quenching on medium viscosity that static and kinamatic mechanisms are in the basis of quenching. The first one dominates within the high values of viscosity, the latter within the law ones. In case of metals on one group the quenching constants are decreased with the growth of the ordinal number of the central atom. This fact supports the great role of the dynamic factor during the quenching of fluorescence of tetrapirrole pigments.