排序方式: 共有14条查询结果,搜索用时 15 毫秒
1.
Wera Myller-Lebedeff 《Mathematische Annalen》1907,64(3):388-416
Ohne Zusammenfassung 相似文献
2.
3.
A series of vanadium(V) complexes with unsymmetrical tridentate Schiff base ligands, obtained by the single condensation of R(−)-1,2-diaminopropane with salicylaldehyde and its derivatives, 2-hydroxy-1-naphthaldehyde, 2-hydroxyacetophenone, 1-hydroxy-2-acetonaphthone and 2-hydroxybenzophenone, were prepared. The complexes were characterized by elemental analysis and by their IR, CD, UV–Vis, 1D (1H, 51V) and 2D (COSY, NOESY, gHSQC) NMR spectra. Crystal structures of the mononuclear complex {R(−)-2-amino-1-N-[(2′-oxido-κO-4′,6′-dimethoxyphenyl)methylene]aminopropane-κ2N}dioxidovanadium(V), VO2(C12H17N2O3), 4, and of the dinuclear complex, di-μ-oxido-bis({R(−)-2-[1-(2-aminopropylimino)ethyl]-4-methylphenolato-κ3N,N′,O}oxidovanadium(V)), V2O4(C11H15N2O)2, 5, have been obtained by X-ray diffraction studies. The structure of 4 was revealed to be a distorted trigonal–bipyramidal coordination geometry, rarely encountered in VO2(tridentate Schiff base) complexes. Complexes 2 and 3 have the ability to catalyze the oxidation of prochiral sulfide substrates PhSR (R = Me, Bz) utilizing hydrogen peroxide or cumene hydroperoxide (CHPO) as the oxidant. 相似文献
4.
Ilia E. SerdiukMicha? Wera Alexander D. RoshalPawe? Sowiński Beata ZadykowiczJerzy B?a?ejowski 《Tetrahedron letters》2011,52(21):2737-2740
According to computational predictions 1,1′,1″-(2,4,6-trihydroxybenzene-1,3,5-triyl)triethanone (triacetylphloroglucinol) (TTT, form a) can exist in five tautomeric forms, among which 2,4,6-tris(1-hydroxyethylidene)-1,3,5-cyclohexanetrione (form e) exhibits thermodynamic stability comparable to that of form a. X-ray investigations reveal that the compound exists in form a in the crystalline solid phase. Analysis of the arrangement of atoms involved in the three intramolecular H-bonds, responsible for the stabilization of tautomer a by 55.4 kcal/mol, suggests that there could be fast H atom (proton) transfer within the hydrogen bonds, bringing about the transformation of a into e and vice versa. Such an effect could explain the unique behaviour and spectral properties of TTT in solutions. 相似文献
5.
Gaowa Naren Wera Larsson Carlos Benitez-Martin Shiming Li Ezequiel Prez-Inestrosa Bo Albinsson Joakim Andrasson 《Chemical science》2021,12(20):7073
A water soluble diarylethene (DAE) derivative that displays exceptionally intense fluorescence from the colorless open form has been synthesized and characterized using UV/vis spectroscopy and fluorescence microscopy. We show that the bright emission from the open form can be rapidly switched using amplitude modulated red light, that is, by light at wavelengths longer than those absorbed by the fluorescent species. This is highly appealing in any context where undesired background fluorescence disturbs the measurement, e.g., the autofluorescence commonly observed in fluorescence microscopy. We show that this scheme is conveniently applicable using lock-in detection, and that robust amplitude modulation of the probe fluorescence is indeed possible also in cell studies using fluorescence microscopy.A water soluble diarylethene derivative displaying exceptionally bright fluorescence in the open isomeric form has been used for emission amplitude-modulation. We apply this scheme in fluorescence microscopy, aiming to suppress undesired background. 相似文献
6.
Wera Myller-Lebedeff 《Mathematische Annalen》1910,70(1):87-93
Ohne Zusammenfassung 相似文献
7.
Dariusz Wyrzykowski Michał Wera Artur Sikorski Dagmara Jacewicz Lech Chmurzyński 《Central European Journal of Chemistry》2011,9(6):1096-1101
The crystal structure of 2-methylpyridinium tetrachloroferrate(III) was determined. The iron cation is tetracoordinated by
chloride anions, and it adopts a slightly distorted tetrahedral coordination with three angles smaller, two almost equal and
one larger than the tetrahedral. The compound is isostructural with its 3-, and 4-methylpyridinium analogues. The thermal
properties of 2-, 3- and 4-methylpyridinium tetrachloroferrates(III) have been studied using TG and DSC techniques. The compounds
exhibit a high stability in the melt.
相似文献
8.
Preparation of Thermocleavable Conjugates Based on Ansamitocin and Superparamagnetic Nanostructured Particles by a Chemobiosynthetic Approach
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Lena Mancuso Dr. Tobias Knobloch Jessica Buchholz Jan Hartwig Dr. Lena Möller Katja Seidel Wera Collisi Dr. Florenz Sasse Prof. Dr. Andreas Kirschning 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(52):17541-17551
A combination of mutasynthesis, precursor‐directed biosynthesis and semisynthesis provides access to new ansamitocin derivatives including new nanostructured particle–drug conjugates. These conjugates are based on the toxin ansamitocin and superparamagnetic iron oxide–silica core shell particles. New ansamitocin derivatives that are functionalized either with alkynyl‐ or azido groups in the ester side chain at C‐3 are attached to nanostructured iron oxide core–silica shell particles. Upon exposure to an oscillating electromagnetic field these conjugates heat up and the ansamitocin derivatives are released by a retro‐Diels–Alder reaction. For example, one ansamitocin derivative exerts strong antiproliferative activity against various cancer cell lines in the lower nanomolar range while the corresponding nanostructured particle‐drug conjugate is not toxic. Therefore, these new conjugates can serve as dormant toxins that can be employed simultaneously in hyperthermia and chemotherapy when external inductive heating is applied. 相似文献
9.
Wera Myller-Lebedeff 《Mathematische Annalen》1908,66(3):325-330
Ohne Zusammenfassung 相似文献
10.