Hydrogen photoinduced

Gerber R B, McCoy A B and Garcia-Vela A 1995 Dynamics of photoinduced reactions in the van der Waals and in the hydrogen-bonded clusters Femtosecond Chemistry Proc. Berlin Conf. Femtosecond Chemistry (Berlin, March 1993) ed J Manz and L Woeste (Weinheim Verlag Chemie) pp 499-531... 

Figure C3.2.7. A series of electron transfer model compounds with the donor and acceptor moieties linked by (from top to bottom) (a) a hydrogen bond bridge (b) all sigma-bond bridge (c) partially unsaturated bridge. Studies with these compounds showed that hydrogen bonds can provide efficient donor-acceptor interactions. From Piotrowiak P 1999 Photoinduced electron transfer in molecular systems recent developments Chem. Soc. Rev. 28 143-50.

Naphthaleneamine. 1-Naphthylamine or a-naphth5iamine/7i5 -i2- can be made from 1-nitronaphthalene by reduction with iron—dilute HCl, or by catalytic hydrogenation it is purified by distillation and the content of 2-naphthylamine can be reduced as low as 8—10 ppm. Electroreduction of 1-nitronaphthalene to 1-naphthylamine using titania—titanium composite electrode has been described (43). Photoinduced reduction of 1-nitronaphthalene on semiconductor (eg, anatase) particles produces 1-naphthylamine in 77% yield (44). 1-Naphthylamine/7J4-J2-. can also be prepared by treating 1-naphthol with NH in the presence of a catalyst at elevated temperature. The sanitary working conditions are improved by gas-phase reaction at... 

Amorphous Silicon. Amorphous alloys made of thin films of hydrogenated siUcon (a-Si H) are an alternative to crystalline siUcon devices. Amorphous siUcon ahoy devices have demonstrated smah-area laboratory device efficiencies above 13%, but a-Si H materials exhibit an inherent dynamic effect cahed the Staebler-Wronski effect in which electron—hole recombination, via photogeneration or junction currents, creates electricahy active defects that reduce the light-to-electricity efficiency of a-Si H devices. Quasi-steady-state efficiencies are typicahy reached outdoors after a few weeks of exposure as photoinduced defect generation is balanced by thermally activated defect annihilation. Commercial single-junction devices have initial efficiencies of ca 7.5%, photoinduced losses of ca 20 rel %, and stabilized efficiencies of ca 6%. These stabilized efficiencies are approximately half those of commercial crystalline shicon PV modules. In the future, initial module efficiencies up to 12.5% and photoinduced losses of ca 10 rel % are projected, suggesting stabilized module aperture-area efficiencies above 11%. 

Fig. 6. Coupling of polymer chains via (a) photoinduced hydrogen abstraction free-radical reactions and (b) nitrene insertion/addition reactions.

A method of detecting herbicides is proposed the photosynthetic herbicides act by binding to Photosystem II (PS II), a multiunit chlorophyll-protein complex which plays a vital role in photosynthesis. The inhibition of PS II causes a reduced photoinduced production of hydrogen peroxide, which can be measured by a chemiluminescence reaction with luminol and the enzyme horseradish peroxidase (HRP). The sensing device proposed combines the production and detection of hydrogen peroxide in a single flow assay by combining all the individual steps in a compact, portable device that utilises micro-fluidic components. 

A photoinduced hydrogen atom transfer in cw-l-(2-pyrrolyl)-2-(2-quino-line)ethene was reported (94JA3171).The rate eonstant A (5 —> 4) increases with increasing temperature from 2.1 10 s at 15.8°C to 7.7 10 s at 39.5°C, giving an aetivation energy of 9.4 keal/mol. 

Early efforts to effect the photoinduced ring expansion of aryl azides to 3H-azepines in the presence of other nucleophiles met with only limited success. For example, irradiation of phenyl azide in hydrogen sulfide-diethyl ether, or in methanol, gave 17/-azepine-2(3//)-thione35 (5% mp 106—107 " O and 2-methoxy-3//-azepine (11 %),2 3 respectively. Later workers194 failed to reproduce this latter result, but found that in strongly basic media (3 M potassium hydroxide in methanol/dioxane) and in the presence of 18-crown-6, 17/-azepin-2(3//)-one was produced in 48% yield. In the absence of the crown ether the yield of azepinone falls to 35%. 

Hydrogenase and its application for photoinduced hydrogen evolution. I. Okura, Coord. Chem. Rev., 1985,68,53 (141). 

Patsoura, A., Kondarides, D.I., and Verykios, X.E. (2006) Enhancement of photoinduced hydrogen production from irradiated Pt/Ti02 suspensions with simultaneous degradation of azo-dyes. Applied Catalysis B Environmental,... 

Kapoor, M.P., Inagaki, S.,and Yoshida, H. (2005) Novel zirconium-titanium phosphates mesoporous materials for hydrogen production by photoinduced water splitting. Journal of Physical Chemistry B, 109 (19), 9231-9238. 

Another photoinduced 1,5-hydrogen shift/twofold Diels-Alder process to give substituted aromatic compounds has been reported by Nair and coworkers [34]. 

Ikegami M, Arai T (2002) Photoinduced intramolecular hydrogen atom transfer in 2-(2-hydroxyphenyl)benzoxazole and 2-(2-hydroxyphenyl)-benzothiazole studied by laser flash photolysis. J Chem Soc Perkin Trans 2 1296-1301... 

P. J. Wagner, B. -S. Park, Photoinduced Hydrogen Atom Abstraction by Carbonyl Compounds, in Organic Photochemistry, Vol. 11. A. Padwa (ed.), Marcel Dekker, New York, 1991, pp. 227-365 and references therein. 

Olefin hydrogenation catalyzed by Fe(CO)s normally requires somewhat severe conditions, typically 150°C and 10 atm H2 (/, p. 64). With near-ultraviolet irradiation the carbonyl becomes effective at ambient conditions for hydrogenation (and isomerization) of olefins (448, 449). Photoinduced labilization of carbonyls is thought to give tricarbonyl species as the active catalysts, e.g.,... 

Successive hydrogen transfers within 60, followed by coordination of olefin and then H2 (an unsaturate route), constitute the catalytic cycle, while isomerization is effected through HFe(CO)3(7r-allyl) formed from 59. Loss of H2 from 60 was also considered to be photoinduced, and several hydrides, including neutral and cationic dihydrides of iridium(III) (385, 450, 451), ruthenium(II) (452) and a bis(7j-cyclopentadienyltungsten) dihydride (453), have been shown to undergo such reductive elimination of hydrogen. Photoassisted oxidative addition of H2 has also been dem-... 

Hydrogen production process by direct photolysis of hydrogen-containing compounds may be based on different types of photosensitizers in parallel with inorganic semiconductors. The model systems for photoinduced hydrogen production with porphyrins and hydrogenase were developed [4],... 

D.-J. Qian, S.-O. Wenk, C. Naikamura, T. Wakayama, N. A. Zorin, J. Miyake (2002) Photoinduced hydrogen evolution by use of porphyrins, EDTA, viologens and hydrogenase in solution and Langmuir-Blodgett films. Int. J. Hydrogen Ener., 27 1481-1487... 

Cationic ions and polyelectrolytes can stabilize the formation of the PS I monolayers at the air-water interface. These complex monolayers can be transferred onto the hydrophobic substrate surfaces by horizontal lifting method. The PS I/polyelectrolyte complex film may be used for the development of a biosystem for the studies on photoinduced electron transfer and for hydrogen evolution. 

Wenk, S. O., D. J. Qian, T. Wakayama, C. Nakamura, N. Zorin, M. Rogner and J. Miyake (2002) Biomolecular device for photoinduced hydrogen production. International Journal of Hydrogen Energy, 27 1489-1493... 

Photoinduced effects, in hydrogenated amorphous silicon, 22 139 Photoinduced electron transfer, 19 111 Photoinitiated cationic curing, J 0 414-415 Photoinitiated cross-linking, 15 157 Photoinitiated free-radical... 

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