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'fluorescence' in keywords Facet   Publication Year 1978  [X]
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1978[X]
1Author    T. Platzner, J. K. ThomasRequires cookie*
 Title    Fluorescence and Proton Nuclear Magnetic Resonance Studies of Thallous Ions - Crown Ether Complexes in Organic Solvents  
 Abstract    The complexing of thallous ions (T1+), with the crown ether dibenzo 18 crown-6 poly-ether (DB) has been studied by NMR, fluorescence, and pulse radiolysis techniques. NMR data show a strong interaction of the T1+ ions with the aromatic moieties. This is also illustrated by a static quenching of the aromatic fluorescence by Tl + . The rates of reactions of T1+ with hydrated electrons eaq~ and pyrene excited singlet states are decreases on complexing the ion by the crown ether. 
  Reference    Z. Naturforsch. 33b, 614—618 (1978); received December 12 1977/March 13 1978 
  Published    1978 
  Keywords    Photochemistry, Fluorescence, Crown Ethers, Biology 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0614.pdf 
 Identifier    ZNB-1978-33b-0614 
 Volume    33 
2Author    Walter FabianRequires cookie*
 Title    Semiempirische SCF-Rechnungen an den angeregten Zuständen von Hydroxy Cumarinen Semiempirical SCF-Calculations of the Excited States of Hydroxycoumarines  
 Abstract    Semiempirical SCF-calculations show that the fluorescence bands of 7-hydroxycoumarin at 1.87 • 10 4 -1,92 • 10 4 cm -1 are most probably due to a phototautomeric form. A topo-logical rule is evaluated to explain the dependence of the fluorescence intensity upon the position of the hydroxyl group in the various isomeric hydroxycoumarines. 
  Reference    Z. Naturforsch. 33b, 628—631 (1978); eingegangen am 16. März 1978 
  Published    1978 
  Keywords    Hydroxycoumarines, Fluorescence, Phototautomerism, PPP-Calculations 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0628.pdf 
 Identifier    ZNB-1978-33b-0628 
 Volume    33 
3Author    J.J S Van Rensen, D. Wong, GovindjeeRequires cookie*
 Title    Characterization of the Inhibition of Photosynthetic Electron Transport in Pea Chloroplasts by the Herbicide 4,6-Dinitro- o-cresol by Comparative Studies with 3-(3,4-Dichlorophenyl)-l,l- dimethylurea  
 Abstract    An attempt to characterize the mechanism of inhibition of photosynthetic electron transport in isolated pea chloroplasts by the herbicide 4,6-dinitro-o-cresol (DNOC) by a comparison with the effects of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) revealed the following: 
  Reference    Z. Naturforsch. 33c, 413 (1978); received April 12 1978 
  Published    1978 
  Keywords    Photosynthesis, Electron Transport, Fluorescence, Herbicides 
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 TEI-XML for    default:Reihe_C/33/ZNC-1978-33c-0413.pdf 
 Identifier    ZNC-1978-33c-0413 
 Volume    33 
4Author    Friederike Koenig, Alfons Radunz, GeorgH. Schmid, Wilhelm MenkeRequires cookie*
 Title    Antisera to the Coupling Factor of Photophosphorylation and Its Subunits  
 Abstract    Stroma-freed chloroplasts were extracted with sucrose palmitate-stearate containing buffer. A fter the addition o f dodecyl sulfate and mercaptoethanol to the extract a series of polypeptides was isolated from the mixture by gel filtration. These polypeptides were later used for immunization. Antisera to four polypeptides reacted in the Ouchterlony double diffusion test with authentic coupling factor yielding a precipitation band. According to the observed apparent molecular weights the polypeptides are the a, ß , 8 and e subunits of the coupling factor. An antiserum to the y subunit has been obtained already previously. A ll antisera inhibit photophosphorylation reactions and electron transport considerably. Addition of gramicidin inhibits photophosphorylation com pletely whereas gramicidin restores electron transport in the assays with the antisera to the a, ß , y and 5 subunit. In the case o f the antiserum to the E subunit gramicidin does not regenerate electron transport. As in the presence of the serum to the £ subunit pH changes in the suspension medium are not observed, this serum seems to open a proton channel. Also, upon addition of dicyclohexyl carbodiimide (D C C D) pH changes in the suspension medium in the assay with antiserum do not reoccur. According to these unexpected results the identity o f the antigen with the e subunit of the coupling factor is not certain. ATP-ase reactions are only inhibited by the antisera to the a and y subunit and what is thought to be the £ subunit. The antiserum to the a subunit uncouples electron transport as the only one when used in sufficient concentrations. The dosis-effect curves o f the inhibition of the electron transport exhibits a maximum. The dosis-effect curves for the other components rise after a lag phase in an approxim ately hyperbolic manner. The inhibitory action on electron transport is exerted by all antisera in the region of the reaction center I or in its immediate vicinity. This is thought to be due to the fact that a protein of the reation center I is inhibited in its function by the increasing proton concentration inside the thylakoid. The inhibition of electron transport by the antiserum to the e subunit is considered to be a direct serum effect. Besides the increase in fluorescence yield, due to the inhibition of electron transport in the region o f photosystem I, decreases of the fluorescence yield are observed in the presence of D CM U, which do not depend on the redox state of Q but rather on the condition of the thylakoid mem­ brane. Moreover, the antisera affect in a differing manner the energy spill-over o f excitation from photosystem I I to photosystem I. 
  Reference    Z. Naturforsch. 33c, 529 (1978); received June 21 1978 
  Published    1978 
  Keywords    Coupling Factor, Antisera, Chloroplasts, Fluorescence 
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 TEI-XML for    default:Reihe_C/33/ZNC-1978-33c-0529.pdf 
 Identifier    ZNC-1978-33c-0529 
 Volume    33 
5Author    Walter FabianRequires cookie*
 Title    W. Fabian * Eigenschaften von Molekülen in angeregten Zuständen 348 Properties of Molecules in Excited States  
 Abstract    Using bisisochinolin derivatives and related compounds it is shown that information about the fluorescent state can be obtained by comparison of experimental fluorescence data and calculated energies of the Si-state assuming various geometries. 
  Reference    Z. Naturforsch. 33b, 332—335 (1978); eingegangen am 7. September 1977 
  Published    1978 
  Keywords    Excited States, Fluorescence, PPP-Calculations, Phototautomerism, Bisisochinolin Deri-vatives 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0332.pdf 
 Identifier    ZNB-1978-33b-0332 
 Volume    33