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151.
Suely L. Galdino Maria C. A. Lima Alexandre J. S. Góes Ivan R. Pitta Cuong Luu-Duc 《光谱学快报》2013,46(7-8):1013-1021
In the present investigation, a study of the electron impact mass spectrometry data is reported for seven compounds of a series of some 3-(4-chlorobenzyl)-5-benzylidene-imidazolidine-2, 4-diones and 3-(4-fluoro or chlorobenzyl)-5-benzylidene-thiazolidine-2, 4-diones previously synthesized. 相似文献
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153.
Ivan M. Kumanyaev Margarita A. Lapitskaya Ljudmila L. Vasiljeva Kasimir K. Pivnitsky 《Mendeleev Communications》2012,22(3):129-131
The stable pyridinium salt of o-iodoxybenzoic acid (PIBX) that is easy to obtain can serve as a convenient substitute of IBX as an oxidant. PIBX is safer, has neutral properties behaves as an equivalent to IBX in the oxidation of alcohols to ketones or aldehydes in polar solvents (DMF, DMSO), and provides higher oxidation rate in THF due to better solubility. 相似文献
154.
Ivan S. Lonin Mikhail A. Grin Anna A. Lakhina Andrey F. Mironov 《Mendeleev Communications》2012,22(3):157-158
Chlorophyll a glycoconjugates were obtained by cross-metathesis between olefin moieties of chlorophyll derivatives and allylβ-galactopyranoside tetraacetate. 相似文献
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156.
We prove a Lifshitz tail bound on the integrated density of states of random breather Schrödinger operators. The potential is composed of translated single-site potentials. The single-site potential is an indicator function of the set tA where t is from the unit interval and A is a measurable set contained in the unit cell. The challenges of this model are that, since A is not assumed to be star-shaped, the dependence of the potential on the parameter t is not monotone. It is also non-linear and not differentiable. 相似文献
157.
Dr. Emilio Brunetti Dr. Lionel Marcelis Dr. Fedor E. Zhurkin Prof. Michel Luhmer Prof. Ivan Jabin Prof. Olivia Reinaud Prof. Kristin Bartik 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(55):13730-13738
In this study, the ligand exchange mechanism at a biomimetic ZnII centre, embedded in a pocket mimicking the possible constrains induced by a proteic structure, is explored. The residence time of different guest ligands (dimethylformamide, acetonitrile and ethanol) inside the cavity of a calix[6]arene-based tris(imidazole) tetrahedral zinc complex was probed using 1D EXchange SpectroscopY NMR experiments. A strong dependence of residence time on water content was observed with no exchange occurring under anhydrous conditions, even in the presence of a large excess of guest ligand. These results advocate for an associative exchange mechanism involving the transient exo-coordination of a water molecule, giving rise to 5-coordinate ZnII intermediates, and inversion of the pyramid at the ZnII centre. Theoretical modelling by DFT confirmed that the associative mechanism is at stake. These results are particularly relevant in the context of the understanding of kinetic stability/lability in Zn proteins and highlight the key role that a single water molecule can play in catalysing ligand exchange and controlling the lability of ZnII in proteins. 相似文献
158.
Gheorghe Ivan 《印度理论与应用数学杂志》2013,44(1):77-93
In this paper we present various geometrical and dynamical properties of the Euler top system in general form. Also the stability problem for the equilibrium states of them are discussed. 相似文献
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