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One-dimensional magnetism and crystal structure ofcatena-di-bromobis(3,5-dimethylpyridine)copper(II)
Johannes A. C. van Ooijen Jan Reedijk Eduard J. Sonneveld Jan W. Visser 《Transition Metal Chemistry》1979,4(5):305-307
Summary Crystals ofcatena-di--bromobis(3,5-dimethylpyridine)copper(II) are monoclinic, space group P21/a. The unit cell constants area=13.900(2),b=14.416(2),c=4.097(1) Å,=93.49(2)°, V=819.4 Å3 and Z=2. The structure was determined from powder data using a Guinier-Johansson focussing powder camera. The structure was solved using a simplex method for function minimization to a conventional R-value of 0.13.The structure consists of infinite linear chains parallel toc in which the copper coordination is distorted elongated octahedral. Cu-Br distances were found to be 2.449(7) and 3.286(7) Å, whereas the Cu-N bond length is 2.02(2) Å. All distances are in the range usually observed for this type of compounds.The antiferromagnetic superexchange interactions between adjacent CuII ions (J = –21 cm–1) has been compared with those observed in structural similar CuBr2L2 compounds. The differences in observed J-values are discussed briefly, in relation to the structural variations. It appears that very small changes in structural parameters strongly affect the magnetic exchange. 相似文献
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Vladimir V. Chernyshev Victor A. Tafeenko Vadim A. Makarov Eduard J. Sonneveld Hendrik Schenk 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1159-1160
The structure of the title compound, C10H17N7O2, was determined using a bond‐restrained Rietveld refinement which gave bond lengths and angles within the expected ranges. Although the two nearly planar (N,N‐dimethylamino)methyleneamino groups are inclined at approximately 46° to the pyrazole ring, the conformations of the two amino chains are different, owing to either a repulsion effect of the pyrazole‐methyl group or a short interatomic contact with the nitro group in one of the chains. 相似文献
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Vladimir V. Chernyshev Victor A. Tafeenko Svetlana Yu. Ryabova Eduard J. Sonneveld Hendrik Schenk 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):982-984
The evidence for thermal isomerization of the title compound, C24H15N5O2, into 2‐[(4‐nitrophenyl)phenylamino]‐5H‐pyrido[3,2‐b]indole‐3‐carbonitrile has been obtained as a consequence of crystal structure determinations from laboratory powder data. 相似文献
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Dirk J. A. De Ridder Kees Goubitz Ed J. Sonneveld Wim Molleman Henk Schenk 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):m596-m598
The structure of lead tartrate, Pb2+·C4H4O62?, has been solved from X‐ray powder diffraction data. The cation exhibits ninefold coordination and the tartrate groups are linked through Pb?O contacts to form a three‐dimensional network. 相似文献
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M.M. de Jong J.K. Rath R.E.I. Schropp P.J. Sonneveld G.L.A.M. Swinkels H.J. Holterman J. Baggerman C.J.M. van Rijn E.A.G. Hamers 《Journal of Non》2012,358(17):2308-2312
We present a novel method to achieve light trapping in thin film silicon solar cells. Unlike the commonly used surface textures, such as Asahi U-type TCO, that rely on light scattering phenomena, we employ embossed periodically arranged micro-pyramidal structures with feature sizes much larger than the wavelength of visible light. Angular resolved transmission of light through these substrates indeed showed diffraction patterns, unlike in the case of Asahi U-type substrates, which show angular resolved scattering. Single junction amorphous silicon (a-Si) solar cells made at 125 °C on the embossed structured polycarbonate (PC) substrates showed an increase in current density by 24% compared to a similar solar cell on a flat substrate. The band gap and thickness of the i-layer made by VHF PECVD are 1.9 eV and 270 nm respectively. A double p-layer (nc-Si:H/a-Si:H) was used to make proper contact with ZnO:Al TCO.Numerical modeling, called DokterDEP was performed to fit the dark and light current–voltage parameters and understand the characteristics of the cell. The output parameters from the modeling suggest that the cells have excellent built-in potential (Vbi). However, a rather high recombination voltage, Vμ, affects the FF and short circuit current density (Jsc) for the cells on Asahi as well as for the cells on PC. A rather high parallel resistance ? 1 MΩ cm2 (obtained from the modeling) infers that there is no significant shunt leakage, which is often observed for solar cells made at low temperatures on rough substrates. An efficiency of more than 6% for a cell on PC shows enormous potential of this type of light trapping structures. 相似文献
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