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V B Evstigneev

Publications and source records attributed to V B Evstigneev.

80 records · Page 5Linked to original sources
PubMedDate not supplied

[Photochemical and photoelectronic properties of components of the photosynthetic apparatus. III. Heat-stimulated conductivity in the lamellar system chlorophyll a--n-chloranil].

Traps with the bedding depth of 0.1 ev in the layers of chlorophyll alpha treated with the electron acceptor n-chloranil were discovered by the method of thermostimulating conductivity. It is suggested that the traps catch mobile vacancies, which occur due to the decomposition of the excited states of the pigment on electron-acceptor centres of the dissociation.

Chloranil↗
PubMedDate not supplied

[Mechanism of activation of the photosensitizing effect of water-soluble analogs of chlorophyll when bound to a polymer].

It has been shown that the order of mixture of photoreduction components of methylene red with ascorbic acid sensitized with clorine e in an aqueous solution of polyvinilpyrrolidone markedly affects the rate and depth of the reaction. The data obtained support the hypothesis that the intensificiation of the sensitized reaction in the presence of polymer is conditioned by joint polymer binding of the reaction components. This binding facilitates the interaction between the electron donor or acceptor with the light-excited pigment.

Ascorbic Acid↗
PubMedDate not supplied

[Impulse photoconductance of solutions of chlorophyll and its analogs. IV. Absolute quantum yield of ion radical formation during photooxidation of chlorophyll a by n-benzoquinone].

The values of absolute quantum yield phi of the formation of free ion-radicals during the illumination of alkohol solutions of chlorophyll alpha (Chl) and rho-benzoquinone (Q) at room temperature were obtained by the method of impulse photoconductance. With an increase of the dielectric constant epsilon of the solvent from approximately 6 to approximately 25 phi increases by two orders ( approximately 10(-3)--approximately 10(-1). That obtained relationship phi (epsilon) is explained by epsilon effect on the efficiency of dissociation of "solvent-shared" ion-radical pair Chls+. Os-. The comparison of experimental data and theoretically expected ones allowed the estimation of some parameters to be obtained which characterize the ion-radical pair: interionic distance (10 A), the dissociation velocity constant ( approximately 10(5)--10(8) s-1), the velocity constant of reverse electron transfer (10(8) s-1), the life time approximately 10(-8) s).

Chlorophyll↗
PubMedDate not supplied

[Photochenical and photoelectronic properties of components of the photosynthetic apparatus. II. Stationary photoconductivity in chlorophyll-acceptor and chlorophyll+protein-acceptor lamellar systems].

It has been shown that the treatment of chlorophyll a amorphous layer surface with the electron acceptor n-chloranyl leads to an increase of photocurrent by 10(1)--10(3) times. The photoinduced polarization in the lamellar system chlorophyll a--n-chloranyll is studied. It has been shown that under the effect of the red light the n-chloranyl layer is negatively charged in relation to the pigment layer. Photoconductivity was discovered in the rigid layers of chlorophyll a+human serum albumin. When a thin film of n-chloranyl is sprayed on the surface of the chlorophyll-protein layer, the photocurrent increases approximately 6--7 times. The experimental results are discussed within the scheme according to which the formation of free radical carriers in chlorophyll layers is carried out by the destruction of excited states, possibly excitons on the electron-acceptor centres of dissociation.

Chemical Phenomena↗
PubMedDate not supplied

[Oxidation-reduction potentials of chlorophyll pigments in photosynthesizing organisms on different levels of evolutionary development].

According to polarographically measured EOred of bacteriochlorophyll "a", chlorobium chlorophyll "660", "b" and "a" chlorophylls (-0.67 V, -0.73 V, -0.79 V, -0.86 V-n.h.e.) and literature data about Eoox of these pigments (+/-0.62 V, + 0.62 V, + 0.78 V, +0.77 V correspondingly) it has been shown that chemical energy stored in the singular photochemical set is increased in the evolution of the photosynthetic apparatus. It has apparently resulted in the possibility of evolutionary approach to utilization of more inert and more accessible (water) electron donors and favoured further development of photosynthesizing organisms.

Bacteria↗