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1.
The reaction of [ReOCl3(PPh3)2] with 5,6-diphenyl-3-(2-pyridyl)-1,2,4-trazine (dppt) has been examined and [ReCl3(OPPh3)(dppt)] has been obtained. The triphenylphosphine oxide can be easily replaced by PPh3 in the reaction of [ReCl3(OPPh3)(dppt)] with an excess of triphenylphosphine. The [ReCl3(OPPh3)(dppt)] and [ReCl3(PPh3)(dppt)] complexes have been structurally and spectroscopically characterized. Their molecular orbital diagrams have been calculated with the density functional theory (DFT) method, and their electronic spectra have been discussed on the basis of time-dependent DFT calculations. The compound [ReCl3(OPPh3)(dppt)] has been studied additionally by magnetic measurement. The magnetic behavior is characteristic of mononuclear complexes with d4 low-spin octahedral Re(III) complexes (3T1g ground state) and arise because of the large spin–orbit coupling (ζ = 2500 cm−1), which gives diamagnetic ground state. 相似文献
2.
A novel transport phenomenon is identified that is induced by inertial Brownian particles which move in simple one-dimensional, symmetric periodic potentials under the influence of both a time periodic and a constant, biasing driving force. Within tailored parameter regimes, thermal equilibrium fluctuations induce the phenomenon of absolute negative mobility (ANM), which means that the particle noisily moves backwards against a small constant bias. When no thermal fluctuations act, the transport vanishes identically in these tailored regimes. ANM can also occur in the absence of fluctuations on grounds which are rooted solely in the complex, inertial deterministic dynamics. The experimental verification of this new transport scheme is elucidated for the archetype symmetric physical system: a convenient setup consisting of a resistively and capacitively shunted Josephson junction device. 相似文献
3.
J. Rymarczyk D. Machura J. Ilczuk 《The European physical journal. Special topics》2008,154(1):187-190
Bi5Ti3FeO15 (BTF) is an example
of bifferoic Aurivillius phase with perovskite layered structure. Materials
on the basis BTF are of substantial interest for new types of
magnetoelectric device applications. In this review we discuss technology of
preparation biferroic ceramic with composition Bi5Ti3FeO15.
The ferroelectric layered Bi5Ti3FeO15 (BTF) Aurivillius
phases were synthesized by solid-phase synthesis reaction from the
conventional mixture of oxides, viz. Bi2O3, Fe2O3,
TiO2. Thermal analysis and mass change efect were used to investigate
synthesis effects in the stoichiometric mixture of powders. The crystalline
structure was checked by X-ray diffraction method at room temperature.
Microstructure was investigated by scanning electron microscopy. 相似文献
4.
We study subgroups of ℤℕ which possess group theoretic properties analogous to properties introduced by Menger (1924), Hurewicz (1925), Rothberger
(1938), and Scheepers (1996). The studied properties were introduced independently by Kočinac and Okunev. We obtain purely
combinatorial characterizations of these properties, and combine them with other techniques to solve several questions of
Babinkostova, Kočinac, and Scheepers.
The first author was supported by the EU Research and Training Network HPRN-CT-2002-00287.
The second author was partially supported by the Koshland Center for Basic Research. 相似文献
5.
The reaction of [ReOBr3(AsPh3)2] with 8-hydroxy-2-methylquinoline-7-carboxylic acid (Hhmquin-7-COOH) has been examined and the [ReOBr2(hmquin-7-COOH)(AsPh3)] complex has been obtained. It was characterized by IR, UV–vis spectroscopy, and single crystal X-ray analysis. The nature
of the frontier orbitals and the electronic transitions involved in the absorption spectrum have been studied by means of
density functional and time-dependent density functional calculations. 相似文献
6.
B. Machura A. ?witlicka D. Tabak J. Polański 《Journal of organometallic chemistry》2011,696(3):731-738
The molecular structure of 7-acetamido-2-methyl-quinoline-5,8-dione has been determined and the reactivity of 7-acetamido-2-methyl-quinoline-5,8-dione (1) and 6-acetamido-2-methyl-quinoline-5,8-dione (2) towards Re(CO)5Cl has been examined. Two novel tricarbonyl rhenium complexes, fac-[Re(CO)3(7-acetamido-2-methyl-quinoline-5,8-dione)Cl]·CHCl3 (3·CHCl3) and fac-[Re(CO)3(6-acetamido-2-methyl-quinoline-5,8-dione)Cl]2·CHCl3 (4·CHCl3), have been synthesized and characterized spectroscopically and structurally. The electronic spectrum of 3 was investigated at the TDDFT level employing B3LYP functional in combination with LANL2DZ. 相似文献
7.
The reactions of [ReX3(MeCN)(PPh3)2] (X = Cl or Br) with 1-(2-pyridylazo)-2-naphthol (HPAN) have been examined and the [ReBr(PAN)2] · 2CHCl3 (1) and [ReCl(PAN)2] (2) complexes have been obtained. The both complexes have been structurally and spectroscopically characterized, and compound 1 has been additionally studied by magnetic measurements. The magnetic behavior is characteristic of mononuclear seven-coordinated Re(III) complex with d4 low-spin configuration, which gives diamagnetic ground state. 相似文献
8.
[ReCl3(MeCN)(PPh3)2] reacts with bis(3,5-dimethypyrazol-1-yl)methane (bdmpzm) in acetone to give [ReCl3(bdmpzm)(PPh3)]. The compound has been studied by IR, UV–Vis spectroscopy and X-ray crystallography. The molecular orbital diagram of [ReCl3(bdmpzm)(PPh3)] has been calculated with the density functional theory (DFT) method. 相似文献
9.
10.
B. Machura M. Jaworska P. Lodowski J. Kusz R. Kruszynski Z. Mazurak 《Polyhedron》2009,28(13):2571-2578
The paper presents a combined experimental and computational study of novel tricarbonyl complex – fac-[Re(CO)3(tp)2Cl] (tp = 1,2,4-triazolo-[1,5-a]pyrimidine). The compound has been characterized spectroscopically and structurally (by single-crystal X-ray diffraction). The absorption and emission spectra of the complex have been discussed on the basis of DFT and time-dependent (TD)DFT calculations. 相似文献