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101.
Oligomeric complexes of some heteroaromatic ligands and aromatic diamines with rhodium and molybdenum tetracarboxylates: 13C and 15N CPMAS NMR and density functional theory studies 下载免费PDF全文
Arkadiusz Leniak Bohdan Kamieński Jarosław Jaźwiński 《Magnetic resonance in chemistry : MRC》2015,53(5):344-352
Seven new oligomeric complexes of 4,4′‐bipyridine; 3,3′‐bipyridine; benzene‐1,4‐diamine; benzene‐1,3‐diamine; benzene‐1,2‐diamine; and benzidine with rhodium tetraacetate, as well as 4,4′‐bipyridine with molybdenum tetraacetate, have been obtained and investigated by elemental analysis and solid‐state nuclear magnetic resonance spectroscopy, 13C and 15N CPMAS NMR. The known complexes of pyrazine with rhodium tetrabenzoate, benzoquinone with rhodium tetrapivalate, 4,4′‐bipyridine with molybdenum tetrakistrifluoroacetate and the 1 : 1 complex of 2,2′‐bipyridine with rhodium tetraacetate exhibiting axial–equatorial ligation mode have been obtained as well for comparison purposes. Elemental analysis revealed 1 : 1 complex stoichiometry of all complexes. The 15N CPMAS NMR spectra of all new complexes consist of one narrow signal, indicating regular uniform structures. Benzidine forms a heterogeneous material, probably containing linear oligomers and products of further reactions. The complexes were characterized by the parameter complexation shift Δδ (Δδ = δcomplex ? δligand). This parameter ranged from around ?40 to ?90 ppm in the case of heteroaromatic ligands, from around ?12 to ?22 ppm for diamines and from ?16 to ?31 ppm for the complexes of molybdenum tetracarboxylates with 4,4′‐bipyridine. The experimental results have been supported by a density functional theory computation of 15N NMR chemical shifts and complexation shifts at the non‐relativistic Becke, three‐parameter, Perdew‐Wang 91/[6‐311++G(2d,p), Stuttgart] and GGA–PBE/QZ4P levels of theory and at the relativistic scalar and spin‐orbit zeroth order regular approximation/GGA–PBE/QZ4P level of theory. Nucleus‐independent chemical shifts have been calculated for the selected compounds. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
102.
Taras O. Banakh Fedor A. Bogomolov Andrij I. Gatalevych Ihor J. Guran Yurij B. Ishchuk Mykola Ya. Komarnytskyi Igor S. Kuz Ivanna O. Melnyk Vasyl M. Petrychkovych Yaroslav G. Prytula Oleh M. Romaniv Oleh B. Skaskiv Ludmyla L. Stakhiv Georgiy T. Sullym Bohdan V. Zabavskyi Volodymir P. Zelisko Mykhajlo M. Zarichnyi 《Central European Journal of Mathematics》2013,11(9):1547-1551
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Thermal decarboxylation converts 1,2-dimethylindazolium-3-carboxylate into indazol-3-ylidene, which reacts in situ with ketones to form stable 1:1 adducts. When the reaction is conducted with aromatic aldehydes in alcohols, redox esterifications to benzoates are observed. Model reactions such as redox esterifications of aromatic aldehydes with sodium alcoholates in the presence of 1,2-dimethylindazolium salt and oxidations of sodium benzylates by 1,2-dimethylindazolium salt to aldehydes lend support to a Cannizzaro-type mechanism of this reaction. 相似文献
107.
We propose a non-equilibrium framework for modelling the evolution of cities, which describes intra-urban migration as an irreversible diffusive process. We validate this framework using the actual migration data for the Australian capital cities. With respect to the residential relocation, the population is shown to be composed of two distinct groups, exhibiting different relocation frequencies. In the context of the developed framework, these groups can be interpreted as two components of a binary fluid mixture, each with its own diffusive relaxation time. Using this approach, we obtain long-term predictions of the cities’ spatial structures, which define their equilibrium population distribution. 相似文献
108.
Bohdan Zapeka Andriy Say Oxana Vlokh Myroslav Kostyrko Iryna Martynyuk-Lototska 《Phase Transitions》2015,88(2):192-200
We have studied special points that appear on the (x, T)-phase diagram of mixed K2xRb2(1?x)Cd2(SO4)3 crystals. This phase diagram has been constructed issuing from the changes in domain structure occurring in the course of phase transitions. We have found that two triple points on the (x, T)-phase diagram of the above solid solutions are very close to each other in the phase space and can change their places or transform into a quadruple point. These special points are associated with disappearance of ferroelectric phases with the symmetries P1 and P21 taking place when Rb2+ are substituted with K2+ ions. 相似文献
109.
Krzysztof Komodziński Joanna Nowak Jolanta Lepczyńska Jan Milecki Bohdan Skalski 《Tetrahedron letters》2012,53(18):2316-2318
In aqueous solution, 6-azido-9-β-d-ribofuranosylpurine undergoes an efficient photoinduced purine ring expansion to give a novel imidazole-fused 1,3,5-triazepinone nucleoside and partial conversion into adenosine. The structure of the major product was established as 1-(β-d-ribofuranosyl)-4,6-dihydroimidazo[4,5-f][1,3,5]triazepin-5(1H)-one based on HRMS and NMR spectral data. 相似文献
110.
The total, effective, low energy lagrangian for K→π+ pseudoscalar decays has been derived for any model involving light elementary pseudoscalars. As an illustration, branching ratios for those decays have been calculated for a two-Higgs doublet model in which only one Higgs doublet couples to quarks. Experimentally allowed regions in the parameter space have been found. 相似文献