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1.
Hans‐Jürgen Holdt Holger Müller Alexandra Kelling Hans‐Joachim Drexler Thomas Müller Thomas Schwarze Uwe Schilde Ines Starke 《无机化学与普通化学杂志》2006,632(1):114-122
Mercury(II) Chloride and Iodide Complexes of Dithia‐ and Tetrathiacrown Ethers The complexes [(HgCl2)2((ch)230S4O6)] ( 1 ), [HgCl2(mn21S2O5)] ( 2 ), [HgCl2(ch18S2O4)] ( 3 ) and [HgI(meb12S2O2)]2[Hg2I6] ( 4 ) have been synthesized, characterized and their crystal structures were determined. In [(HgCl2)2((ch)230S4O6)] two HgCl2 units are discretely bonded within the ligand cavity of the 30‐membered dichinoxaline‐tetrathia‐30‐crown‐10 ((ch)230S4O6) forming a binuclear complex. HgCl2 forms 1 : 1 “in‐cavity” complexes with the 21‐membered maleonitrile‐dithia‐21‐crown‐7 (mn21S2O5) ligand and the 18‐membered chinoxaline‐dithia‐18‐crown‐6 (ch18S2O4) ligand, respectively. The 12‐membered 4‐methyl‐benzo‐dithia‐12‐crown‐4 (meb12S2O2) ligand gave with two equivalents HgI2 the compound [HgI(meb12S2O2)]2[Hg2I6]. In the cation [HgI(meb12S2O2)]+ meb12S2O2 forms with the cation HgI+ a half‐sandwich complex. 相似文献
2.
3.
Natalia Tiessen Dr. Nico Schwarze Mira Keßler Beate Neumann Dr. Hans-Georg Stammler Prof. Dr. Berthold Hoge 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(43):11041-11044
While alkyl-substituted siloxanes are widely known, virtually nothing is known about perfluoroalkyl siloxanes and their congener species, the silanols and silanolates. We recently reported on the tris(pentafluoroethyl)silanide ion, [Si(C2F5)3]−, which features Lewis amphoteric character deriving from the pentafluoroethyl substituents and their strong electron-withdrawing properties. Transferring this knowledge, we investigated the Lewis amphoteric behavior of the tris(pentafluoroethyl)silanolate, [Si(C2F5)3O]−. In order to examine such Lewis amphoteric behavior, we first developed a strategy for the synthesis of the corresponding silanol Si(C2F5)3OH, which readily condenses at room temperature to the hexakis(pentafluoroethyl)disiloxane, (C2F5)3SiOSi(C2F5)3. Deprotonation of Si(C2F5)3OH employing a sterically demanding phosphazene base allows the characterization of the first example of a dimeric triorganosilanolate: the dianionic hexakis(pentafluoroethyl)disilanolate, [{Si(C2F5)3O}2]2−, implies Lewis amphoteric character of the monomeric [Si(C2F5)3O]− anion. 相似文献
4.
W. Krämer R. Weber K. -P. Kistner J. Schwarze 《Mathematical Methods of Operations Research》1980,24(8):B275-B278
Ohne Zusammenfassung 相似文献
5.
Thomas Schwarze Wulfhard Mickler Dr. Carsten Dosche Dr. Roman Flehr Tillmann Klamroth Dr. Hans‐Gerd Löhmannsröben Prof. Dr. Peter Saalfrank Prof. Dr. Hans‐Jürgen Holdt Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(6):1819-1825
Fluoroionophores of fluorophore–spacer–receptor format were prepared for detection of PdCl2 by fluorescence enhancement. The fluorescent probes 1 – 13 consist of a fluorophore group, an alkyl spacer and a dithiomaleonitrile PdCl2 receptor. First, varying the length of the alkylene spacer (compounds 1 – 3 ) revealed a dominant through‐space pathway for oxidative photoinduced electron transfer (PET) in CH2‐bridged dithiomaleonitrile fluoroionophores. Second, fluorescent probes 4 – 9 containing two anthracene or pyrene fragments connected through CH2 bridges to the dithiomaleonitrile unit were synthesized. Modulation of the oxidation potential (EOx) through electron‐withdrawing or ‐donating groups on the anthracene moiety regulates the thermodynamic driving force for oxidative PET (ΔGPET) in bis(anthrylmethylthio)maleonitriles and therefore the fluorescence quantum yields (Φf), too. The new concept was confirmed and transferred to pyrenyl ligands, and fluorescence enhancements (FE) greater than 3.2 in the presence of PdCl2 were achieved by 7 and 8 (FE=5.4 and 5.2). Finally, for comparison, monofluorophore ligands 10 – 13 were synthesized. 相似文献
6.
J. Schwarze 《Mathematical Methods of Operations Research》1989,33(4):240-240
7.
Dr. Thomas Schwarze Janine Riemer Dr. Sascha Eidner Prof. Hans‐Jürgen Holdt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(32):11306-11310
A highly K+‐selective two‐photon fluorescent probe for the in vitro monitoring of physiological K+ levels in the range of 1–100 mM is reported. The two‐photon excited fluorescence (TPEF) probe shows a fluorescence enhancement (FE) by a factor of about three in the presence of 160 mM K+, independently of one‐photon (OP, 430 nm) or two‐photon (TP, 860 nm) excitation and comparable K+‐induced FEs in the presence of competitive Na+ ions. The estimated dissociation constant (Kd) values in Na+‐free solutions (KdOP=(28±5) mM and KdTP=(36±6) mM ) and in combined K+/Na+ solutions (KdOP=(38±8) mM and KdTP=(46±25) mM ) reflecting the high K+/Na+ selectivity of the fluorescent probe. The TP absorption cross‐section (σ2PA) of the TPEF probe+160 mM K+ is 26 GM at 860 nm. Therefore, the TPEF probe is a suitable tool for the in vitro determination of K+. 相似文献
8.
Schwarze M Keilitz J Nowag S Parapat RY Haag R Schomäcker R 《Langmuir : the ACS journal of surfaces and colloids》2011,27(10):6511-6518
Platinum and palladium nanoparticles, supported and stabilized by polymeric core-shell architectures, proved to be active catalysts for hydrogenation reactions. Here, two different reactions were used as probes to investigate the influence of the polymeric support: the hydrogenation of α-methyl styrene (AMS) to cumene and the partial hydrogenation of 1,5-cyclooctadiene (COD). We found that the stability of the nanoparticles and the rate of reaction are higher in the presence of a hydrophobic octadecyl shell within a three-shell polymer system. The kinetic study of AMS hydrogenation showed much higher activities for palladium nanoparticles than for platinum nanoparticles, and the obtained results (e.g., 35 kJ/mol for the activation energy) are of the same order of magnitude as reported earlier for palladium supported on alumina. A methanol/n-heptane biphasic mixture was tested for catalyst recycling and allowed for highly efficient catalyst separation with very low metal leaching. 相似文献
9.
Prof. Dr. J. Schwarze 《Mathematical Methods of Operations Research》1978,22(1):173-194
Zusammenfassung Bei der Netzplantechnik und ihren Anwendungen werden unterschiedliche Modelle und Verfahren behandelt. Unter Verwendung der Graphentheorie wird ein verallgemeinertes Netzplanmodell beschrieben, das die bekannten Modelle (Vorgangsknotennetzplan, Vorgangspfeilnetzplan, Ereignisknotennetzplan) als Sonderfälle enthält.
Summary In network-analysis and its applications one usually distinguishes between activity-on-arrow, activity-on-node and event-on-node networks. Using the theory of graphs, a generalized deterministic network model is described, containing the well known techniques as special cases.相似文献
10.
In this work, the simulation of earings in cup drawing by means of a recently developed anisotropic combined hardening material model is discussed. The model represents a multiplicative formulation of anisotropic elastoplasticity in the finite strain regime with nonlinear kinematic and isotropic hardening. Plastic anisotropy is described by the use of second-order structure tensors as additional arguments in the representation of the yield function and the plastic flow rule. The evolution equations are integrated by a form of the exponential map that preserves the plastic volume and the symmetry of the internal variables. Finite element simulations of cylindrical cup drawing processes are performed by means of ABAQUS/Standard where the discussed material model has been implemented into a user-defined reduced integration solid-shell element. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献