title: [Effect of the dielectric constant of the medium on the photooxidation of chlorophyll a by parabenzoquinone].
abstract: Spectrophotometric study was carried out of the effect of medium polarity on the parabenzoquinone photooxidation of chlorophyll "a" at lower temperature using as solvents toluene and CCl4 containing different quantities of polaric solvents, methanole, ethanole, amilic alkohol, acetone. It is shown that the photoreaction with the formation of primary photooxidized form of the pigment starts only if some amount of the polar component is in the medium. The data are in favour of the suggestion that chlorophyll and quinone in non-polar medium form an reaction complex which disintegrates under the given conditions at a definite value of medium polarity.
mesh_terms: D000096:Acetone; D002251:Carbon Tetrachloride; D002734:Chlorophyll; D000431:Ethanol; D000432:Methanol; D000439:Pentanols; D010777:Photochemistry; D011809:Quinones; D012997:Solvents; D014050:Toluene
chemical_list: D000439:Pentanols; D011809:Quinones; D012997:Solvents; D000096:Acetone; D002734:Chlorophyll; D014050:Toluene; D000431:Ethanol; D002251:Carbon Tetrachloride; D000432:Methanol
vernacular_title: O vliianii diélektricheskoĭ postoiannoĭ sredy na fotookislenie khlorofilla a parabenzokhinonom