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31.
Akutsu H Akutsu-Sato A Turner SS Le Pevelen D Day P Laukhin V Klehe AK Singleton J Tocher DA Probert MR Howard JA 《Journal of the American Chemical Society》2002,124(42):12430-12431
Normal state conductivity and superconductivity together with bulk magnetic susceptibility and magnetization measurements have been measured for two molecular charge-transfer salts: beta' '-(ET)4[(H3O)Ga(C2O4)3]G (ET = bis(ethylenedithio)tetrathiafulvalene, G = pyridine for compound I and nitrobenzene for compound II). With the exception of the included guest molecules (G) the crystal structures are almost identical. Both show minima in their electrical transport at 130 K for I and at 160 K for II, but at lower temperatures their behaviors differ markedly. The resistance of I reaches a maximum at 50 K with a further small peak at 2 K and possible superconductivity only below 2 K, whereas that of II increases continuously down to 7.5 K, where an abrupt transition to a superconducting state occurs. 相似文献
32.
S. T. Howard J. P. Huke I. W. Parsons S. J. Till 《International journal of quantum chemistry》1991,39(1):71-91
The usefulness of the MS -Xα method for calculating molecular transition properties is investigated in a study of NO2. Two-dimensional potential surfaces are obtained in C2v symmetry for the X?2A1/Ã2B2 system. Potential curves that approximately follow the asymmetric stretch coordinate are also presented: On investigation, no symmetry-broken solutions were found. At all nuclear geometries investigated, the muffin-tin sphere radii were chosen by an energy-minimization technique. The inclusion of corrections to the muffin-tin form of the Xα total energy is shown to be essential, if the computed surfaces are to be qualitatively correct. The transition dipole moment connecting the two states is evaluated as a function of nuclear coordinates, using the transition-state approximation. Finally, the radiative decay of a single vibronic level in NO2 is modeled and the relevance to experiment is discussed. 相似文献
33.
34.
Inorganic oxide core, polymer shell nanocomposite as a high K gate dielectric for flexible electronics applications 总被引:1,自引:0,他引:1
Maliakal A Katz H Cotts PM Subramoney S Mirau P 《Journal of the American Chemical Society》2005,127(42):14655-14662
Organic/inorganic core shell nanoparticles have been synthesized using high K TiO(2) as the core nanoparticle, and polystyrene as the shell. This material is easy to process and forms transparent continuous thin films, which exhibit a dielectric constant enhancement of over 3 times that of bulk polystyrene. This new dielectric material has been incorporated into capacitors and thin film transistors (TFTs). Mobilities approaching 0.2 cm(2)/V.s have been measured for pentacene TFTs incorporating the new TiO(2) polystyrene nanostructured gate dielectric, indicating good surface properties for pentacene film growth. This novel strategy for generating high K flexible gate dielectrics will be of value in improving organic and flexible electronic device performance. 相似文献
35.
Howard M. Colquhoun 《Transition Metal Chemistry》1981,6(1):57-59
Summary Ligating dinitrogen, in the complexes,trans-M(N2)2(Ph2PCH2CH2PPh2)2 (where M=Mo or W) may be acylated by trifluoroacetic anhydride, to give trifluoroacetyldiazenido complexes in high yield. Unlike corresponding reactions with acyl halides, trifluoroacetylation proceeds under nonradical conditions, and a mechanism analogous to that of protonation is suggested.Dinitrogen-derived ligands may also be acylated by (CF3CO)2O, so that the methyldiazenido ligand is converted into a methyl (trifluoroacetyl) hydrazido (2-) ligand, and the acetyldiazenido ligand undergoes transacylation to give a trifluoroacetyl diazenido derivative.New complexes were characterised by i.r.,19F and1H n.m.r. spectra, and by elemental analysis.Part 1 is ref. 10 相似文献
36.
Martin R. Bryce Peter J. Skabara Adrian J. Moore Andrei S. Batsanov Judith A.K. Howard Vanessa J. Hoy 《Tetrahedron》1997,53(52):1002-17794
Reactions of tetrathiafulvalenyllithium (TTF-Li) with a range of aldehydes and ketones have been explored for the first time, to provide an efficient route to mono-functionalised TTF derivatives of general formulae TTF-CH(OH)R (R = alkyl, phenyl, tetrathiafulvalenyl and ferrocenyl) and TTF-CR(OH)R′ (R = alkyl, phenyl, R′ = alkyl, phenyl, tetrathiafulvalenyl, ferrocenyl, and R-R′ = fluorenyl). Subsequent transformations involving the reactive alcohol group of some of these compounds are reported. The structures of the three title compounds have been established by single-crystal X-ray analysis. 相似文献
37.
Christopher J. Chandler Leslie W. Deady James A. Reiss Vasilios Tzimos 《Journal of heterocyclic chemistry》1982,19(5):1017-1019
The preparation of a series of macrocycles, formed by reaction of HO-(-CH2-CH2-O-)nH with 1,10-phenanthroline-2,9-dicarbonyl chloride (n = 2,3,4) and 1,8-naphthyridine-2,7-dicarbonyl chloride (n = 3,4), is described. An improved synthetic route to 2,7-dimethyl-1,8-naphthyridine 9 is also reported. 相似文献
38.
Howard C. Clark Anil B. Goel Chun S. Wong 《Journal of organometallic chemistry》1980,190(4):C101-C104
Simple synthetic routes to the mixed ligand complexes PtLL'X2 and PtLL'XY (L' = PEt3; L = phosphine, arsine, etc.; X = Cl and Y = Cl, H or Me) are described; unexpectedly, these display an extensive chemistry without disproportionation, although in some cases ligand scrambling does occur. 相似文献
39.
S. N. Dmitrieva N. I. Sidorenko A. I. Vedernikov L. G. Kuz’mina J. A. K. Howard T. M. Buslaeva S. P. Gromov 《Russian Chemical Bulletin》2007,56(5):993-1002
The condensation reaction of 1,2-bis(2-haloethoxy)-4-nitrobenzenes with acyclic α,ω-(oxa)alkanedithiols in the presence of
alkali metal carbonates produced a series of nitrobenzodithiacrown ethers with macrocycles of different size. The structures
of three ethers were established by X-ray diffraction. A new method was developed for the synthesis of nitrobenzomonothia-15-crown-5
ether. Nitro derivatives of benzodithiacrown ethers were tested as reagents for extraction of palladium(II), platinum(IV), and rhodium(III) from hydrochloric acid solutions. Extraction of PdII salts was found to be highly selective compared to that of PtIV and RhIII salts. Benzodithia-15-crown-5 ether is the most efficient extractant for palladium(II). Reduction of nitrobenzothiacrown ethers with hydrazine hydrate in the presence of a platinum catalyst afforded their amino
derivatives.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 958–966, May, 2007. 相似文献
40.
The synthesis of [2.2](2,6,2',7')naphthalenophane -1,11 - diene 4 has been effected by pyrolysis of the bis-sulphoxide 10, in turn prepared by a ring-contraction procedure of the [3.3]dithiacyclophane 7. The diene 4 has been fully characterized by spectroscopic and chemical methods. The variable-temperature 1H NMR spectra of the diene 4 indicated that the compound undergoes conformational flipping in solution and has a conformational energy barrier ΔG≠25°. 14.9 kcal mol-1 and a coalescence temperature Tc 38° for the internal protons Hc and Hc' (at 100 MHz). These results differ from those previously recorded. A complete assignment of the pmr spectrum of the cyclophane diene 4 at 270 MHz is presented together with the spectrum of the corresponding saturated [2.2]cyclophane 3. 相似文献