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111.
112.
M. Ramos Silva A. Matos Beja J. A. Paixo L. Alte da Veiga J. Martin‐Gil 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):542-545
The title compound, [Fe3(C5H11NO2)6O(H2O)3](MnCl4)2Cl3·6H2O, contains a triiron core linked by a μ3‐bridging oxide ion. Each of the iron(III) ions has a distorted octahedral environment, being coordinated, in addition to the oxide ion, by four neutral betaine molecules and one water molecule. The N‐alkylated α‐amino acid betaine is present in the dipolar zwitterionic form and chelates pairs of Fe atoms at the vertices of the triangular [Fe3O]7+ ionic core. The Fe complex has a crystallographically imposed D3 symmetry. The water molecules fully exhaust their potential as hydrogen donors, forming a two‐dimensional hydrogen‐bond network in planes parallel to (001). 相似文献
113.
M. Ramos Silva A. J. F. N. Sobral J. A. Silva A. C. Santos S. M. Melo A. Matos Beja 《Journal of chemical crystallography》2007,37(10):695-698
Abstract A new substituted pyrrole, a precursor of meso-free-porphyrins, has been synthesised and characterised by single-crystal X-ray
diffraction: monoclinic, P21/c with a = 14.607(9) ?, b = 5.136(2) ?, c = 25.832(17) ?, β = 108.14(5)°, Mr = 349.41, V = 1841.6(18) ?3, Z = 4. The molecules are assembled in centrosymmetric dimers via strong N–H...O hydrogen bonds. The dimers are gathered
into chains via C–H...π intermolecular interactions.
Graphical abstract The molecules in 4-benzyl-5-methoxymethyl-3-methyl-1H-pyrrole-2-carboxylic acid benzyl ester are joined in dimmers by strong
hydrogen bonds. The dimmers are aggregated in chains running along the b axis through C-H...?€ intermoleculear interactions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
114.
115.
Zegers RG van Den Berg AM Brandenburg S Fleurot FR Fujiwara M Guillot J Hannen VM Harakeh MN Laurent H van Der Schaaf K van Der Werf SY Willis A Wilschut HW 《Physical review letters》2000,84(17):3779-3782
The (nat)Pb(3He,tp) reaction at E(3He) = 177 MeV was studied to identify 2Planck's over 2piomega isovector monopole strength in Bi isotopes. Monopole strength was found in the region -45
相似文献
116.
An analogy is stressed between the order-parameter symmetries of the two-dimensional d-pairing wave superconductors and of liquid-crystal mesophases formed from achiral bent-shaped molecules. It leads to a definition of a class of liquid-crystal states which are the analogs of the unconventional superconducting states, and are characterized by a loss of discrete symmetry operations of the parent state. 相似文献
117.
Background
Neurons require an elaborate system of intracellular transport to distribute cargo throughout axonal and dendritic projections. Active anterograde and retrograde transport of mitochondria serves in local energy distribution, but at the same time also requires input of ATP. Here we studied whether brain-type creatine kinase (CK-B), a key enzyme for high-energy phosphoryl transfer between ATP and CrP in brain, has an intermediary role in the reciprocal coordination between mitochondrial motility and energy distribution. Therefore, we analysed the impact of brain-type creatine kinase (CK-B) deficiency on transport activity and velocity of mitochondria in primary murine neurons and made a comparison to the fate of amyloid precursor protein (APP) cargo in these cells, using live cell imaging. 相似文献118.
van Der Lee AM van Druten NJ van Exter MP Woerdman JP Poizat JP Grangier P 《Physical review letters》2000,85(22):4711-4714
We investigate the impact of the Petermann-excess-noise factor K>/=1 on the possibility of intensity noise squeezing of laser light below the standard quantum limit. Using an N-mode model, we show that squeezing is limited to a floor level of 2(K-1) times the shot noise limit. Thus, even a modest Petermann factor significantly impedes squeezing, which becomes impossible when K>/=1.5. This appears as a serious limitation for obtaining sub-shot-noise light from practical semiconductor lasers. We present experimental evidence for our theory. 相似文献
119.
Pinho e Melo TM Nunes CM Soares MI Paixão JA Beja AM Silva MR 《The Journal of organic chemistry》2007,72(12):4406-4415
The chemistry of diazafulvenium methides generated by the thermal extrusion of sulfur dioxide from 2,2-dioxo-1H,3H-pyrazolo[1,5-c] [1,3]thiazoles is described. The diazafulvenium methides unsubstituted at C-7 participate in [8 pi + 2 pi] cycloadditions giving pyrazolo-annulated heterocycles resulting from the addition across the 1,7-position. 1-Methyl-diazafulvenium methides and 7,7-dimethyl-diazafulvenium methides undergo intramolecular sigmatropic [1,8]H shifts giving vinyl-1H-pyrazoles. 相似文献
120.
Joana A. Silva Ana C. Santos Ana T. Marques Manuela Ramos Silva Ana Matos Beja Abílio J. F. N. Sobral 《Journal of chemical crystallography》2008,38(4):301-303
Abstract A new pyrazine compound, has been synthesised and characterised by single-crystal X-ray diffraction: monoclinic, P21/c with a = 11.0707(3) ?, b = 5.23700(10) ?, c = 16.6997(5) ?, β = 103.5385(16)°, Mr = 376.40, V = 941.30(4) ?3, Z = 2. Each molecule possesses C
i
symmetry with the two halves of the molecule related by an inversion centre. C–H···π and C=O···π interactions held the molecules
together.
Index Abstract C–H···π and C=O···π intermolecular interactions in dibenzyl-3,6-dimethylpyrazine-2,5-dicarboxylate
Joana A. Silva, Ana C. Santos, Ana T. Marques, Manuela Ramos Silva, Ana Matos Beja, Abílio J. F. N. Sobrala
In dibenzyl-3,6-dimethylpyrazine-2,5-dicarboxylate, each molecule possesses C
i
symmetry. The molecules are assembled in chains via carbonyl···π interactions.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献