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101.
S Spirk F Belaj N Hurkes R Pietschnig 《Chemical communications (Cambridge, England)》2012,48(67):8398-8400
A high yield synthesis of the first silanedithiolate silanolate is reported which spontaneously assembles forming an inorganic rugby ball shaped 32 vertex polyhedral cluster stabilized by sterically demanding 2,6-dimesitylphenyl substituents and two LiCl units. 相似文献
102.
Fraga R Zacconi F Sussman F Ordóñez-Morán P Muñoz A Huet T Molnár F Moras D Rochel N Maestro M Mouriño A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(2):603-612
Based on the crystal structures of human vitamin D receptor (hVDR) bound to 1α,25-dihydroxy-vitamin D(3) (1,25 D) and superagonist ligands, we previously designed new superagonist ligands with a tetrahydrofuran ring at the side chain that optimize the aliphatic side-chain conformation through an entropy benefit. Following a similar strategy, four novel vitamin D analogues with aromatic furan side chains (3a, 3b, 4a, 4b) have now been developed. The triene system has been constructed by an efficient stereoselective intramolecular cyclization of an enol triflate (A-ring precursor) followed by a Suzuki-Miyaura coupling of the resulting intermediate with an alkenyl boronic ester (CD-side chain, upper fragment). The furan side chains have been constructed by gold chemistry. These analogues exhibit significant pro-differentiation effects and transactivation potency. The crystal structure of 3a in a complex with the ligand-binding domain of hVDR revealed that the side-chain furanic ring adopts two conformations. 相似文献
103.
Arumuganathan T Volpe M Harum B Wurm D Belaj F Mösch-Zanetti NC 《Inorganic chemistry》2012,51(1):150-156
The preparation and oxygen-atom-transfer (OAT) reactivity of oxoimido complexes [MoO(N-t-Bu)(t-Bu(2)-4-Rpz)(2)] [where R = H (1), Br (2), and Me (3); t-Bu(2)pz = 3,5-di-tert-butylpyrazolate] are reported. The reaction of the potassium salt of the respective pyrazolate ligands and the molybdenum oxoimido precursor, [MoO(N-t-Bu)Cl(2)(dme)] (dme = dimethoxyethane), in toluene afforded complexes 1-3 in good yields. The complexes were fully characterized by (1)H and (13)C NMR and IR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray crystallography. The solid-state structures reveal that, in each case, the molybdenum center is coordinated by one oxo, one N-t-Bu group, and two sterically demanding pyrazolate ligands via their two adjacent nitrogen atoms in an η(2) fashion. Coordination around the metal center is severely distorted from octahedral and might be seen as closely approaching a distorted trigonal-prismatic geometry, which is relevant to the active site of dimethyl sulfoxide reductase in its oxidized form. The potential utility of all of the complexes 1-3 for OAT reactivity toward PMe(3) at room temperature is examined, and plausible mechanistic pathways are explored by density functional theory calculations. Furthermore, the complexes reported here open a new and convenient entry into mixed oxoimidomolybdenum complexes. 相似文献
104.
Mareš Kamil Vavřinec Šebesta Ferdinand John Jan 《Journal of Radioanalytical and Nuclear Chemistry》2019,322(2):377-387
Journal of Radioanalytical and Nuclear Chemistry - A novel metal sulfide: potassium niobium sulfide (KNbS) was prepared by hydrothermal method. The morphology and composition of KNbS were... 相似文献
105.
Ferdinand Beckhoff 《Rendiconti del Circolo Matematico di Palermo》1997,46(3):451-464
The space Id(A) of closed two-sided ideals of a Banach algebra A carries the weak topology. IfA is separable Id(A) is expected to satisfy topological countability conditions. Some results concerning first and second countability are achieved. 相似文献
106.
Ferdinand Beckhoff 《Rendiconti del Circolo Matematico di Palermo》1988,37(3):469-473
Korovkin closures in commutative algebrasU can often be characterized by certain setsU(T, E, F), whereT?U is the set,E, F?U′. The example given here shows, that the conjectured generalization to non-commutativeC *-algebras does not hold. 相似文献
107.
H. D. Hochheimer E. Gmelin W. Bauhofer Ch. von Schnering-Schwarz H. G. von Schnering J. Ihringer W. Appel 《Zeitschrift für Physik B Condensed Matter》1988,73(2):257-263
The real part of the dielectric constant , the heat capacityc
p, the infrared reflectivity, and the X-ray diffraction of TlGaSe2 have been measured in the temperature range from 12 K (30K) to 300 K. Both andc
p show two anomalies at about 110 K and 120 K. A study of the hysteresis loop as well as an investigation of the dielectric dispersion in the microwave region show that the phase below 110 K is ferroelectric. The crystal structure remains nearly unchanged in the course of the phase transition. The loss of the
symmetry (C2/cCc) results from small positional shifts of the T1 atoms in the ab plane accompanied by a discontinuity in the axial ratios. We suggest, that the ferroelectricity is caused by the stereochemically active electron lone pair configuration of the Tl+ ion. Thus TlGaSe2 may provide the first example for ferroelectricity caused by this mechanism. 相似文献
108.
Ladislav Habala Ferdinand Devínsky Alexander E. Egger 《Journal of Coordination Chemistry》2018,71(7):907-940
Urease plays a significant role in the pathogenesis of several diseases and also has practical implications in other fields, such as agriculture or chemical analysis. Among the multitude of chemical species known to inhibit urease, metal complexes stand out as a special category due to their specific mechanism of action, distinct from purely organic substances. Their inhibitory activity seems to depend on the type of metal and its oxidation state as well as on the coordination environment of the central atom. Furthermore, the study of the interaction between metal ions and their complexes with urease renders valuable insights into detailed catalytic mechanisms of this enzyme. This brief survey attempts to provide an overview of the published research on urease inhibition by metal complexes. 相似文献
109.
110.
Ferdinand Beckhoff 《Proceedings of the American Mathematical Society》1997,125(10):2859-2866
Let the space of closed two-sided ideals of a Banach algebra carry the weak topology. We consider the following property called normality (of the family of finite subsets of : if the net in converges weakly to , then for all we have (e.g. -algebras, with compact . For a commutative Banach algebra normality is implied by spectral synthesis of all closed subsets of the Gelfand space , the converse does not always hold, but it does under the following additional geometrical assumption: .