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The Reaction of Cs2[Tc(NO)F5] with BF3 in Acetonitrile: Formation and Structure of [{Tc(NO)(CH3CN)4}2(μ‐F)](BF4)3
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Samundeeswari Mariappan Balasekaran Adelheid Hagenbach Johann Spandl Ulrich Abram 《无机化学与普通化学杂志》2017,643(18):1146-1149
The deep blue, paramagnetic Cs2[TcII(NO)F5] is formed during reactions of pertechnetate, acetohydroxamic acid, and CsF in aqueous HF. A reaction of Cs2[Tc(NO)F5] with BF3 · MeOH in acetonitrile gives yellow blocks of the fluorido‐bridged dimer [{TcI(NO)(CH3CN)4}2F](BF4)3. The compound is stable as solid and in acetonitrile solutions. The complex cation contains a bent μ‐F– ligand and two linear nitrosyl groups. 相似文献
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Karmakar S Das O Ghosh S Zangrando E Johann M Rentschler E Weyhermüller T Khanra S Paine TK 《Dalton transactions (Cambridge, England : 2003)》2010,39(45):10920-10927
A new dicompartmental dioxime ligand (H(2)L) with m-xylyl spacer between the donor sites has been synthesised by Schiff-base condensation of α,α'-diamino-m-xylene and diacetyl monooxime. The ligand reacts with copper(ii) salts giving rise to hexanuclear tricationic copper(II) cage complexes [Cu(II)(6)(μ(3)-O···H···O-μ(3))L(3)(H(2)O)(6)]X(3) (X = BF(4), 1a; X = ClO(4), 1b). The complexes have been characterised by different analytical and spectroscopic techniques and confirmed the hexanuclear structure even in solution. Single crystal X-ray diffraction studies of both the complexes revealed a very similar core structure with three dicompartmental ligands supporting two triangular Cu(3)O cores that share a proton, located on their common threefold axis and involved in a strong hydrogen bond interaction (O···O distance of 2.517(2) ?). Two Cu(3)O units do not superimpose but are staggered and disposed with the formation of a helicate structure. However both the enantiomers are present in the centrosymmetric space group. The facing Cu(3)-planes in 1a are separated at a distance of 3.476 ?. The temperature dependence of the magnetic behaviour of the hexanuclear complex 1a clearly indicates an overall antiferromagnetic exchange interaction between the spin carriers in the cage having two Cu(3)O subunits and leaves a single unpaired electron in each triangular unit. The unpaired electrons in the two Cu(3)O units interact antiferromagnetically through hydrogen bonding giving rise to an overall singlet-spin ground state. 相似文献
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Nadine Werth Mathias S. Müller Johann Meier Alexander W. Koch 《Optics Communications》2011,284(9):2317-2322
Using Laser-based Speckle-Interferometers, the shape of optically rough surfaces can be measured precisely and contactlessly from variable measuring distances even in regions of difficult access. This work is concerned with the integration of a micromirror array (MMA) into an electronic Speckle-Pattern-Interferometer. With the adaptive optics, it is intended to adapt the phasefront of a reference wave to critical surface areas of the measurement object. Yet, due to the topography of the MMA, diffraction effects occur which affect the phase and intensity of the generated wavefront. We demonstrate how these diffraction effects can be efficiently modelled by a Fraunhofer diffraction method. We compare the results of this model to theoretical data obtained by a numerical Fresnel diffraction model and to measurement data obtained from a measurement setup incorporating a multi mirror array. 相似文献
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Harry J. Martin Dr. Thomas Magauer Dr. Johann Mulzer Prof. Dr. 《Angewandte Chemie (International ed. in English)》2010,49(33):5614-5626
Kendomycin is a novel polyketide having a unique quinone methide ansa structure and an impressive biological profile. Herein we provide a chronological overview of the synthetic work towards the title compound. Thus far, over a period of about eight years, eight groups worldwide have published on their synthetic efforts resulting in five total syntheses, one formal synthesis, and a number of fragment syntheses. Most approaches roughly mimic the biogenetic pathway, starting with an aromatic polyphenol subunit to which a polyketide chain is attached. Subsequent key steps include macrocyclization and the formation of the densely substituted tetrahydropyran ring, and then a late‐stage oxidation and lactol formation. 相似文献
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