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131.
过氧化氢既可用作环境友好的绿色氧化剂,也可用作燃料电池中的太阳能燃料,因而受到越来越多的关注.本文综述了太阳能驱动分子氧氧化水制备过氧化氢及其作为绿色氧化剂和燃料的研究进展.利用太阳能将水的2e-和4e-氧化与分子氧的2e-还原相结合,使光催化生产过氧化氢成为可能;本文讨论了与2e-和4e-水氧化选择性及2e-和4e-... 相似文献
132.
Hiroaki Aikawa 《Proceedings of the American Mathematical Society》1997,125(1):229-234
Let be a bounded domain in , , and let . We consider positive functions on such that for all bounded harmonic functions on . We determine Lipschitz domains having such with .
133.
Fukuzumi S Kotani H Ohkubo K Ogo S Tkachenko NV Lemmetyinen H 《Journal of the American Chemical Society》2004,126(6):1600-1601
We have successfully achieved the electron-transfer (ET) state of 9-mesityl-10-methylacridinium ion, produced by a single step photoinduced electron transfer, which has a much longer lifetime (e.g., 2 h at 203 K) and higher energy (2.37 eV) than that of the natural system without loss of energy due to multistep electron-transfer processes. 相似文献
134.
Hydrogenation of carbon dioxide (P(H2/CO2)= 5.5/2.5 MPa) into formic acid (HCOOH) under acidic conditions (pH 2.5-5.0) in water has been achieved by using water-soluble ruthenium aqua catalysts [(eta6-C6Me6)RuII(L)(OH2)]SO4 (L = 2,2'-bipyridine or 4,4'-dimethoxy-2,2' bipyridine). 相似文献
135.
Osako T Tachi Y Doe M Shiro M Ohkubo K Fukuzumi S Itoh S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(1):237-246
Crystal structures of the copper(I) complexes 1(X), 2, and 3 of a series of tridentate ligands L1(X), L2, and L3, respectively (L1(X): p-substituted derivatives of N,N-bis[2-(2-pyridyl)ethyl]-2-phenylethylamine; X=H, Me, OMe, Cl, NO(2); L2: N,N-bis[2-(2-pyridyl)ethyl]-2-methyl-2-phenylethylamine; L3: N,N-bis[2-(2-pyridyl)ethyl]-2,2-diphenylethylamine) were solved to demonstrate that all the copper(I) complexes involve an eta(2) copper-arene interaction with the phenyl ring of the ligand sidearm. The Cu(I) ion in each complex has a distorted tetrahedral geometry consisting of the three nitrogen atoms (one tertiary amine nitrogen atom and two pyridine nitrogen atoms) and C(1)-C(2) of the phenyl ring of ligand sidearm, whereby the Cu-C distances of the copper-arene interaction significantly depend on the para substituents. The existence of the copper-arene interaction in a nonpolar organic solvent (CH(2)Cl(2)) was demonstrated by the observation of an intense MLCT band around 290 nm, and the magnitude of the interaction was evaluated by detailed analysis of the (1)H and (13)C NMR spectra and the redox potentials E(1/2) of the copper ion, as well as by means of the ligand-exchange reaction between the phenyl ring and CH(3)CN as an external ligand. The thermodynamic parameters DeltaH(o) and DeltaS(o) for the ligand-exchange reaction with CH(3)CN afforded a quantitative measure for the energy difference of the copper-arene interaction in the series of copper(I) complexes. Density functional studies indicated that the copper(I)-arene interaction mainly consists of the interaction between the d(z(2) ) orbital of Cu(I) and a pi orbital of the phenyl ring. The copper(I) complexes 1(X) reacted with O(2) at -80 degrees C in CH(2)Cl(2) to give the corresponding (micro-eta(2):eta(2)-peroxo)dicopper(II) complexes 4, the formation rates k(obs) of which were significantly retarded by stronger d-pi interaction, while complexes 2 and 3, which exhibit the strongest d-pi interaction showed significantly lower reactivity toward O(2) under the same experimental conditions. Thus, the d-pi interaction has been demonstrated for the first time to affect the copper(I)-dioxygen reactivity, and represents a new aspect of ligand effects in copper(I)-dioxygen chemistry. 相似文献
136.
Masaaki Yamabe Seisaku Kumai Shunichi Samejima Seiji Munekata 《Journal of fluorine chemistry》1980,16(6):521
As an extension of our studies on the reaction of I(CF2CF2)nI (n = 2 and 3) with sulfur trioxide1), the reaction of 1,2-diiodo-tetrafluoroethane with sulfur trioxide was studied.1,2-Diiodo-tetrafluoroethane was reacted with an excess of sulfur trioxide at reaction temperature ranging from 0°C to 115°C.The products were not the expected iododifluoroacetyl fluoride and/ or oxalyl fluoride, but thermally stable derivatives with polysulfate structures.These derivaties could be converted nearly quantitatively into iododifluoroacetyl fluoride and ethyl iododifluoroacetate by potassium fluoride and by ethanol, respectively.The possible structures of these derivatives will be discussed based on these results and 19F-NMR studies. 相似文献
137.
[reaction: see text] Photocatalytic oxygenation of tetraphenylethylene (TPE) with oxygen occurs efficiently via electron-transfer reactions of TPE and oxygen with a photogenerated electron transfer state of 9-mesityl-10-methylacridniium ion, followed by the radical-coupling reaction between TPE radical cation and O2*- to produce 1,2-dioxetane selectively. The further photocatalytic cleavage of the O-O bond of dioxetane affords benzophenone as the final oxygenated product. 相似文献
138.
139.
140.
Rates of Diels-Alder cycloaddition of anthracenes with p-benzoquinone and its derivatives as well as rates of hydride-transfer reactions from 10-methyl-9,10-dihydroacridine to the same series of p-benzoquinones are accelerated significantly in the presence of metal ions in acetonitrile. An extensive comparison of the catalytic effects of metal ions in electron transfer from one-electron reductants (cobalt tetraphenylporphyrin and decamethylferrocene) to p-benzoquinones with those in the Diels-Alder reactions of the quinones as well as the hydride-transfer reactions has revealed that the catalysis of metal ions in each case is ascribed to the 1:1 and 1:2 complexes formed between the corresponding semiquinone radical anions and metal ions. The transient absorption and ESR spectra of the semiquinone radical anion-metal ion complexes are detected directly in the electron-transfer reduction of p-benzoquinone derivatives in the presence of metal ions. The catalytic reactivities of a variety of metal ions in each reaction are well correlated with the energy splitting values of pi(g) levels because of the complex formation between O(2)(.-) and M(n+), which are derived from the g(zz) values of the ESR spectra of the O(2)(.-)-M(n+) complex. 相似文献