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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(24):6806-6806
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Khalid A. Al‐Farhan 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):o531-o532
In the title compound, C18H15OP·C11H8O2, co‐crystallization of triphenylphosphine oxide with 1‐naphthoic acid yields a supramolecular structure held together by one O—H⋯O and three C—H⋯O hydrogen bonds. The O—H⋯O hydrogen bond [O⋯O = 2.592 (2) Å] has little effect on the O=P bond distance. 相似文献
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Treatment of 3-deoxy-1, 2:5, 6-di-O-isopropylidène-3C-méthylene-α-D -ribo-hexofuranose with aromatic nitrile oxides led to spiro-Δ2-isoxazolines, whereas a Δ1-pyrazoline was obtained by reacting the same C-methylenic sugar with diazomethane. Properties of these compounds, a new class of carbohydrates, and 5, 6-di-O-acetyl derivatives thereof are described. 相似文献
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Bifunctionalized 1 H‐Phosphirene and g1‐1‐Phosphaallene Tungsten Complexes The tungsten(0) complex [{(Me3Si)2HCPC(Ph)=N}W(CO)5] 1 reacts upon heating with acetylene derivatives 2 a–d in toluene to form benzonitrile and the complexes [{(Me3Si)2HCPC(R)=COEt} · W(CO)5] 5 a–d ( 5 a : R = SiMe3; 5 b : R = SiPh3; 5 c : R = SnMe3; 5 d : R = SnPh3) and [{(Me3Si)2HCP=C=C(OEt)R} · W(CO)5] 6 a, b ( 6 a : R = SnMe3; 6 b : R = SnPh3), which have been isolated by chromatography; complexes 5 c and 6 a have been characterized as mixtures. Spectroscopic and mass spectrometric data are discussed. The crystal structure of the compound 5 a was determined by X‐ray single crystal structure analysis ( 5 a : space group P21/n, Z = 4, a = 977.6(2) pm, b = 1814.6(4) pm, c = 1628.0(4) pm, β = 93.95(2)°). 相似文献
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David J. Nielsen Claudio Pettinari Brian W. Skelton Allan H. White 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(8):o542-o544
Low‐temperature studies of the simple variously substituted imidazole types 4‐phenyl‐1H‐imidazole, C9H8N2, 1‐benzyl‐1H‐imidazole, C10H10N2, and 1‐mesityl‐1H‐imidazole, C12H14N2, extend comparisons between parent imidazole species and their derivatives, the pronounced double‐bond localization opposite the substituted N atom common to simple neutral species being redistributed aromatically on protonation. 相似文献
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《Electrochemistry communications》2002,4(7):535-539
The potential of zero charge (pzc) of Pd(1 1 1) has been determined in dilute NaF solutions by measuring the Gouy–Chapman minimum of the double-layer capacity. For a massive Pd(1 1 1) single crystal electrode a pzc of −0.12 V vs. SCE has been found. The corresponding values for thin Pd(1 1 1) overlayers on Au(1 1 1) have also been determined. While the pzc of the first, pseudomorphic Pd layer on Au(1 1 1) is −0.09 V vs. SCE, the pzc of a five monolayers thick Pd film on Au(1 1 1) is practically identical to the pzc of the massive Pd(1 1 1) electrode. By comparing pzc's and work functions for Au(1 1 1) and Pd(1 1 1), the dipole contribution to the potential drop across the Pd(1 1 1)/water interface is estimated. 相似文献
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Elbieta Sto Tadeusz Lis Veneta Videnova‐Adrabiska 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):m114-m116
In the title compound, poly[sodium‐μ4‐3,5‐dicarboxybenzenesulfonato‐κ4O:O′:O′′:O′′′‐μ2‐urea‐κ2O:N] monohydrate], {[Na(C8H5O7S)(CH4N2O)]·H2O}n, the organic anions are arranged almost vertically within (001) monolayers, with the sulfonate and carboxylic acid groups pointing into the interlayer region. The inversion‐related aromatic rings of the anions inside the layers are arrayed via offset face‐to‐face interactions into molecular stacks along the crystallographic a axis. The `up' and `down' arrangement of the aromatic portions makes both faces of the layers ionic and hydrophilic, whereas the interiors of the layers are primarily hydrophobic. The interleaving of the anions is such that the carboxylic acid groups are oriented more toward the interior than are the sulfonate groups. The aromatic rings in neighbouring layers are arranged in a herring‐bone fashion. The coordination sphere of the Na+ ions contains two sulfonate and two carboxylic acid O atoms, from a total of four different acid anions belonging to two neighbouring anionic monolayers. The urea molecules are positioned between translation‐related anionic stacks inside the (001) layers, serving a triple function, viz. they fill in the large meshes (empty cavities) formed within the anionic–cationic network, and they provide additional Na+ coordination and hydrogen‐bond sites. 相似文献
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Thomas Steiner 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):1033-1034
In the crystalline 1:1 molecular complex of triphenylmethanol (TPMeOH) and triphenylphosphine oxide (TPPO), C19H16O·C18H15OP, molecular dimers are formed which are linked by O—H?O=P hydrogen bonds. The dimers are aligned by sixfold phenyl embraces to form columns. The structure is disordered with half a dimer per asymmetric crystal unit, i.e. with only one molecular site which is half‐occupied by both TPMeOH and TPPO. 相似文献
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The influence of different substrates on the molecular orientation of organometallic polymer Pt-DEBP, [Pt(PBu3)2CCC12H8CC]n, has been investigated by NEXAFS spectroscopy. Thin films were deposited on HOPG, Au/Si(1 1 1), Cr/Si(1 1 1), Si(1 1 1) and stainless steel. The assignment of the spectral features has been carried out on the basis of previous STEX calculations performed on phenylacetylene model molecule in gas phase and adsorbed on Pt(1 1 1) and Cu(1 0 0). Angular dependent analysis of the π* resonance occurring at 285.50 eV photon energy deriving by the benzene carbon orbitals showed a polarisation effect for all substrates. A preferential molecular orientation at nearly 40° to the surface normal was observed. This result might be explained by the strong interaction between sp and sp2 carbons of the organic diethynylbiphenyl DEBP moiety contained in close chains, leading to polymer self-assembling. 相似文献
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《Chemical physics》2005,309(1):33-39
The interaction of propyne with the Pt(1 1 1) and Pd(1 1 1) surfaces has been studied by means of the generalised gradient approach of density functional theory using periodic slab models. For both surfaces, the most stable adsorption mode of propyne is di-σ/π mode where the hydrocarbon is σ-bonded to two metal atoms with some additional π bonding to a third adjacent surface atom. The adsorption geometry is a highly distorted propyne with the C1 and C2 in a nearly sp2 hybridisation. Two equivalent surface structures have been found on Pt and Pd. These correspond to the adsorption on the fcc or hcp hollow sites. The adsorption energies on Pt(1 1 1) and Pd(1 1 1) are predicted to be ∼−197 and −161 kJ mol−1, respectively. The electronic factors that control the chemisorption have been analysed by means of the projected density of states. 相似文献
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Lusbely M. Belandria Asilo J. Mora Gerzon E. Delgado Alexander Briceo 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(2):o88-o91
The title salt, C6H12NO2+·C6H7O4− or ISO+·CBDC−, is an ionic ensemble assisted by hydrogen bonds. The amino acid moiety (ISO or piperidine‐4‐carboxylic acid) has a protonated ring N atom (ISO+ or 4‐carboxypiperidinium), while the semi‐protonated acid (CBDC− or 1‐carboxycyclobutane‐1‐carboxylate) has the negative charge residing on one carboxylate group, leaving the other as a neutral –COOH group. The –+NH2– state of protonation allows the formation of a two‐dimensional crystal packing consisting of zigzag layers stacked along a separated by van der Waals distances. The layers extend in the bc plane connected by a complex network of N—H...O and O—H...O hydrogen bonds. Wave‐like ribbons, constructed from ISO+ and CBDC− units and described by the graph‐set symbols C33(10) and R33(14), run alternately in opposite directions along c. Intercalated between the ribbons are ISO+ cations linked by hydrogen bonds, forming rings described by the graph‐set symbols R66(30) and R42(18). A detailed analysis of the structures of the individual components and the intricate hydrogen‐bond network of the crystal structure is given. 相似文献
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《无机化学与普通化学杂志》2018,644(2):100-108
1‐tert‐Butyl‐1H‐1,2,4‐triazole (tbtr) was found to react with copper(II) chloride or bromide to give the complexes [Cu(tbtr)2X2]n and [Cu(tbtr)4X2] (X = Cl, Br). 1‐tert‐Butyl‐1H‐tetrazole (tbtt) reacts with copper(II) bromide resulting in the formation of the complex [Cu3(tbtt)6Br6]. The obtained crystalline complexes as well as free ligand tbtr were characterized by elemental analysis, IR spectroscopy, thermal and X‐ray analyses. For free ligand tbtr, 1H NMR and 13C NMR spectra were also recorded. In all the complexes, tbtr and tbtt act as monodentate ligands coordinated by CuII cations via the heteroring N4 atoms. The triazole complexes [Cu(tbtr)2Cl2]n and [Cu(tbtr)2Br2]n are isotypic, being 1D coordination polymers, formed at the expense of single halide bridges between neighboring copper(II) cations. The isotypic complexes [Cu(tbtr)4Cl2] and [Cu(tbtr)4Br2] reveal mononuclear centrosymmetric structure, with octahedral coordination of CuII cations. The tetrazole compound [Cu3(tbtt)6Br6] is a linear trinuclear complex, in which neighboring copper(II) cations are linked by single bromide bridges. 相似文献
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Yasushi Kai Jun Sakamoto Takashi Nakagawa Nobuko Kanehisa Masahiro Katsura 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e596-e597
In the title compound, C14H10N4, all the atoms are close to being coplanar (r.m.s. deviation 0.0098 Å) except for the imino H atoms. The molecule forms a one‐dimensional chain through intermolecular N—H?N hydrogen bonds. 相似文献
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Alexandre V. Ivachtchenko Dmitry V. Kravchenko Valentina I. Zheludeva Dmitry G. Pershin 《Journal of heterocyclic chemistry》2004,41(6):931-939
Starting from 1H‐pyrazol, a wide number of 1‐alkyl‐1H‐pyrazol‐4‐yl and 1‐alkyl‐1H‐pyrazol‐5‐ylboronic acids and their pinacol esters were synthesized and characterized. The key step in the described methodology is the regioselective lithiation of the pyrazole ring. The synthesized pinacolates are stable under prolonged storage and can be used as convenient reagents in organic synthesis. 相似文献