Kautsky mechanism

The formation of singlet oxygen through the Kautsky mechanism [78] was observed not only when sensibilization was induced by adsorbed dye molecules but also in case when sensibilization was provided by deposited oxides of transition metals [92, 93]. This is very important for understanding numerous heterogeneous and photocatalytic processes. 

Using semiconductor sensors we examined several peculiarities of photoemission of C>2. It occurred that concentration of C>2 in gaseous phase exhibits a linear dependence on intensity of exciting light which is completely consistent with the Kautsky mechanism (see the experimental schematics). Moreover, these results indicate that in this case the readsorption processes (as well as local heating of sensibilizer) are not important. 

Energy Transfer. In the Kautsky mechanism for quenching triplet state molecules, electronic excitation energy is transferred from Mi to the oxygen molecules, as follows (20) ... 

This hypothesis assumes the intermediate formation of singlet oxygen ( 0,), mechanism first proposed by Kautsky.u The energy levels of singlet oxygens areO,(1S,)=37.8 kcal mol-1, Oa(,A,)=22.5 kcal mol-1. 0, state is likely to be formed in an energy transfer step. 

Below the region of regular ice impact, belt-forming Fucus vesiculosus dominates, representing 30 5% of the plant biomass in the basin (Kautsky et al., 1992). However, as shown and discussed by Waern (1952) and confirmed by Kiirikki (1996), even Fucus, being well adapted to heavy mechanical stress, might be absent at locations of extreme wave exposition. Fucus serratus is co-occurring with Fucus vesiculosus in the southern parts of the Swedish coast (Malm, 1999 Malm et al., 2001). 

Ann Rev Plant Physiol 23 87-112 Goodwin TW (1952) The Comparative Biochemistry of Carotenoids. Chapman and Hall, London Goodwin TW (ed) (1976) Chemistry and Biochemistry ofPlant Pigments. Academic Press, New York Govindjee (1995) Sixty-three years since Kautsky Chi a fluorescence. Aust J Plant Physiol 22 131-160 Govindjee and Govindjee R (1965) Action spectra for the appearance of difference absorption bands at 480 and 520 nm in illuminated Chlorella cells and their possible significance to a two-step mechanism of photosynthesis. Photochem Photobiol 4 675- 683... 

Chijimatsu, M., Fujita, T., Sugita, Y., Amemiya, K. and Kobayashi, A. 2001. Field experiment, results and THM behavior in the Kamaishi mine experiment. Int.J. of Rock Mechanics and Mining Sciences, Vol. 38, No. 1, pp.67-78 Jing, L., Stephansson, O., Tsang, C-F. and Kautsky, F. 1996. DECOVALEX -Mathematical Models of Couples T-H-M Processes for Nuclear Waste Repositories. Executive Summary for Phases I, II and HI, SKI Report 96 58. 

The validity of the Kautsky singlet oxygen mechanism seems to be confirmed both theoretically (21) and experimentally (5, 11, 12, 13, 31,... 

Immobilized photosensitizers derive ultimately from the work of Kautsky and deBruijn ( ) In determining the mechanism of "Photodynamic Action" ( ), they carried out the following... 

Since the two mechanisms are kinetically identical Kautsky (1939) devised an elegant experiment to determine the ease of diffusion of the reactive intermediate. Silica gel suspensions of the sensitizer and of the substrate were prepared separately and were mixed mechanically. Irradiation of the mixtm-e in the presence of oxygen led to rapid oxidation of the substrate. This result favors the intermediacy of a very mobile species and was presented as evidence in favor of the mechanism in Eq. (173). 

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