Journal of the Chemical Society, Faraday Transactions最新文献_第8页

Vibrational spectrum of 1,1,1-trifluoroethane 1,1,1-三氟乙烷的振动谱

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A805068F

G. Nivellini, F. Tullini, A. Celli, M. Becucci

引用次数: 5

Dispersion of ruthenium oxide on barium titanates (Ba6Ti17O40,Ba4Ti13O30,BaTi4O9and Ba2Ti9O20)and photocatalytic activity for water decomposition 氧化钌在钛酸钡(Ba6Ti17O40,Ba4Ti13O30, bati4o9和Ba2Ti9O20)上的分散及水分解的光催化活性

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A704947A

M. Kohno, Takatoshi Kaneko, S. Ogura, Kazunori Sato, A. Y. Inoue

{"title":"Dispersion of ruthenium oxide on barium titanates (Ba6Ti17O40,Ba4Ti13O30,BaTi4O9and Ba2Ti9O20)and photocatalytic activity for water decomposition","authors":"M. Kohno, Takatoshi Kaneko, S. Ogura, Kazunori Sato, A. Y. Inoue","doi":"10.1039/A704947A","DOIUrl":"https://doi.org/10.1039/A704947A","url":null,"abstract":"Ruthenium oxide supported on barium titanates (Ba6Ti17O40, Ba4Ti13O30, BaTi4O9 and Ba2Ti9O20) was employed as a photocatalyst for water decomposition. The RuCl3-impregnated titanates were subjected to either reduction or reduction–oxidation. High-resolution electron microscopic images demonstrated that ruthenium metal and ruthenium oxides were uniformly dispersed on BaTi4O9 with an average particle size of 2.6 nm. Similar uniform ruthenium oxide dispersions were observed for the other barium titanates; the average particle sizes were 4.7 nm for Ba6Ti17O40, 2.3 nm for Ba4Ti13O30, and 4.4 nm for Ba2Ti9O20. Particle size distributions were narrower for BaTi4O9 and Ba4Ti13O30, and slightly larger for Ba6Ti17O40 and Ba2Ti9O20. Stoichiometric production of oxygen and hydrogen occurred for a RuO2/BaTi4O9 photocatalyst. A small amount of hydrogen and no oxygen were produced from the other barium titanates (Ba6Ti17O40, Ba4Ti13O30 and Ba2Ti9O20) combined with ruthenium oxides. EPR spectra at 77 K in He or O2 with UV irradiation demonstrated that a strong signal, assigned to a surface O- radical, appeared for BaTi4O9 but not for the other barium titanates. These produced small complicated signals, indicating that only BaTi4O9 has a high efficiency for photoexcited charge formation. Raman spectra showed that a strong single peak at a high wavenumber of 860 cm-1, characteristic of BaTi4O9, was absent in the rest of the barium titanates. The different photocatalytic properties among these titanates are discussed on the basis of structure differences of the barium titanates, and the presence of internal fields; a long Ti–O bond in the distorted TiO6 octahedra is proposed to be important in photocatalysis.","PeriodicalId":17286,"journal":{"name":"Journal of the Chemical Society, Faraday Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74002218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 64

Computer simulation of the effect of salt on the hydrophobic effect 计算机模拟了盐对疏水效应的影响

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A806899B

R. Mancera

引用次数: 22

Vibrational modes and structure of vanadium(V) complexes in M2SO4–V2O5 (M=K or Cs) molten salt mixtures M2SO4-V2O5 (M=K或Cs)熔盐混合物中钒(V)配合物的振动模式和结构

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A807047D

S. Boghosian

{"title":"Vibrational modes and structure of vanadium(V) complexes in M2SO4–V2O5 (M=K or Cs) molten salt mixtures","authors":"S. Boghosian","doi":"10.1039/A807047D","DOIUrl":"https://doi.org/10.1039/A807047D","url":null,"abstract":"Raman spectra of the M2SO4–V2O5 (M=K or Cs) binary molten salt systems have been recorded at temperatures up to 570°C under an oxygen atmosphere and at different compositions in the range 0.25⩽X(V2O5)⩽0.50. 33 mol% V2O5 mixtures contain VV polymeric complexes consisted of VO3- and VO2(SO4)23- units participating in chain-like or network-like configurations, while VO2SO4- units were also detected in the K2SO4–V2O5 system. The spectral changes occurring upon addition of V2O5 up to X(V2O5)=0.50 are interpreted to indicate: (i) a gradual transformation of VO2(SO4)23- units, where vanadium is six-coordinated, to VO2SO4-, where vanadium is four-coordinated and (ii) extensive linking of polymeric chains giving rise to large and complex three-dimensional networks. The most characteristic bands observed for the various units comprising the polymeric complexes in the K2SO4–V2O5 system are assigned as follows: (i) for VO2(SO4)23- at 1042 (terminal VO stretches of six-coordinated vanadium), 940 (terminal S–O stretches of sulfate), 880 (bridging S–O), 668, 408 and 227 cm-1; (ii) for VO3- units at 950 (terminal VO stretches of four-coordinated vanadium), 486 and 365 cm-1 and (iii) for VO2SO4- units at 983 (terminal VO stretches of four-coordinated vanadium) and 862 cm-1 (bridging S–O). Similar values have been found for the band wavenumbers in the Cs2SO4–V2O5 system. The spectral data are discussed in terms of possible structural models. The spectral changes upon freezing the Cs2SO4–V2O5 molten mixtures with 0.33⩽X(V2O5)⩽0.50 indicate formation of the 1:1 V2O5·Cs2SO4 solid. This conclusion is confirmed also by powder XRD spectroscopy. For the first time, high-temperature vibrational spectroscopy has been used to establish the structural and vibrational properties of M2SO4–V2O5 (M=K or Cs) molten salt mixtures.","PeriodicalId":17286,"journal":{"name":"Journal of the Chemical Society, Faraday Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79257101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 18

Metal complexes in a constrained environment 受限环境下的金属配合物

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A802967I

L. Stievano, S. Calogero, L. Storaro, M. Lenarda, F. Wagner

引用次数: 4

Infrared matrix isolation study of H2SO4 and its complexes with H2O 硫酸及其与水配合物的红外基质分离研究

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A706675I

A. Givan, L. A. Larsen, A. Loewenschuss, C. Nielsen

引用次数: 41

The reaction between aluminium and dimethyl ether Comparative study of density functional theory and EPR results 铝与二甲醚反应的密度泛函理论与EPR结果的比较研究

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A706667H

Torbjörn Fängström, A. Kirrander, L. Eriksson, S. Lunell

{"title":"The reaction between aluminium and dimethyl ether Comparative study of density functional theory and EPR results","authors":"Torbjörn Fängström, A. Kirrander, L. Eriksson, S. Lunell","doi":"10.1039/A706667H","DOIUrl":"https://doi.org/10.1039/A706667H","url":null,"abstract":"Stationary points on the surface describing the reaction between aluminium and dimethyl ether (DME) have been located using density functional theory at the B3LYP level with a 6-31G(d,p) basis set. Hyperfine coupling constants (HFCC) of Al and the proton attached to it, as well as total energies, were computed at all stable structures using the B3LYP and BP86 functionals and the 6-311+G(2df,p) basis. Compared to earlier theoretical studies, additional stable conformers have been identified. An initial addition complex is formed between Al and CH3OCH3, located 4–9 kcal mol−1 below the free reactants in energy, depending on computational method. A first transition state connects the addition complex with a structure in which one hydrogen has migrated to the Al atom, whereafter a more stable C–H insertion structure is reached through a second transition state. A second reaction path leading to two C–O insertion products, starting from the addition complex, is also described. The most stable products are the cis and trans conformers of an open chain C–O insertion product which lie 58–65 kcal mol−1 below the reactants in energy. Among the C–H insertion products the most stable ones are cyclic cis and trans structures, which are found to lie 9–10 kcal mol−1 below the reactants.","PeriodicalId":17286,"journal":{"name":"Journal of the Chemical Society, Faraday Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85539682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Periodic and aperiodic patterns in non-equilibrium PbI2/PbF2 precipitate systems 非平衡PbI2/PbF2沉淀体系的周期性和非周期性模式

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A801391H

M. Attieh, N. al-Kassem, R. Sultan

{"title":"Periodic and aperiodic patterns in non-equilibrium PbI2/PbF2 precipitate systems","authors":"M. Attieh, N. al-Kassem, R. Sultan","doi":"10.1039/A801391H","DOIUrl":"https://doi.org/10.1039/A801391H","url":null,"abstract":"Precipitate systems display a variety of beautiful patterns. Of particular interest are those patterns formed by more than one insoluble salt. Guided by a prior theoretical model, we present here experiments on two precipitate patterning using PbI2 and PbF2 as the precipitating salts, in agar gel medium. Throughout the study, a solution of Pb2+ is allowed to diffuse into a homogeneous solution of the two halides and not the reverse. Two major categories of patterns are obtained: periodic, in which the band locations follow a rigorous spacing law, and aperiodic, where the bands occupy erratic spatial positions. The former patterns are obtained at large values of the mean concentration difference Δ [≡(ΔI + ΔF)/2, where ΔI = [Pb2+]0 − 1/2[I−]0 and similarly for ΔF], while the latter are formed at relatively low values of Δ. The periodic patterns show two different types of behaviour. When ΔI = ΔF, one type of bands containing the two precipitates is obtained, obeying the spacing law rigorously. When ΔI ≠ ΔF, two types of bands are observed with two distinct spacing laws. A chemical analysis of the bands shows that in both cases, the latter consist of a complete overlap of PbI2 and PbF— (i.e. no alternation) consistent with the initial ratio of concentrations (of I− to F−). Different observations favour the mechanism of post-nucleation patterning. Some special features indicate the role of the kinetics of particle growth in deciding whether we obtain one or two types of bands (and hence one or two spacing laws).","PeriodicalId":17286,"journal":{"name":"Journal of the Chemical Society, Faraday Transactions","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82150381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Non-ideality of binary mixtures Water[ndash ]methanol and water[ndash ]acetonitrile from the viewpoint of clustering structure 从聚类结构的角度看二元混合物水甲醇和水乙腈的非理想性

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A705777F

A. Wakisaka, H. Abdoul-Carime, Y. Yamamoto, Y. Kiyozumi

引用次数: 115

Experimental excess volumes of organic carbonate+alkane systems. Estimation of the parameters of the Nitta–Chao model for this kind of binary mixture 有机碳酸盐+烷烃体系的实验过量体积。这类二元混合物Nitta-Chao模型参数的估计

Journal of the Chemical Society, Faraday Transactions Pub Date : 1998-01-01 DOI: 10.1039/A800934A

J. García, L. Lugo, M. Comuñas, E. R. López, Josefa Fernández

引用次数: 35