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31.
Hubert Schmidbaur Sybille Lauteschläger Beatrix Milewski-Mahrla 《Journal of organometallic chemistry》1983,254(1):59-68
Reaction of lithiated bis(diphenylphosphino)amine, [(C6H5)2P]2N? Li+, with K2PtCl4 or PdCl2 (in the presence of trimethylphosphine) yields the homoleptic bis[bis(diphenylphosphino)amide] complexes I and II, respectively. With NiCl2/(CH3)3P the chloro-bridged dinuclear complex III is obtained. A symmetrical bonding of the Ph2P-·N-·PPh2 anion to the metal through the phosphorus atoms is indicated for these diamagnetic, deep-yellow (I, II) or red (III) complexes by 31P NMR spectroscopy (J(PtP) 1812 Hz for I). I and II are dissolved in CF3COOH with protonation at the nitrogen atoms to give bis(diphenylphosphino)amine complexes IV and V, respectively (J(PtP) 2080 Hz for IV). IV and V are 1:2 electrolytes in CH3NO2. Methylation of I-III with CH3OSO2F leads to the bis(diphenylphos-phino)methylamine complexes VI-VIII, of which the palladium compound VII has been structurally characterized by single crystal X-ray diffraction. VII contains a planar CNP2PdP2NC skeleton and is thus based on planar ligand arrays both at Pd and at the two N atoms. 相似文献
32.
Hans Gantner 《Fresenius' Journal of Analytical Chemistry》1977,284(1):39-40
33.
Beatrix C. Hiesmayr 《Foundations of Physics Letters》2001,14(3):231-245
First, a generalized Bell inequality for different times and for different quasi-spin states is developed. We focus on special quasi-spin eigenstates and times. The inequality based on a local realistic theory is violated by the CP-violating parameter [1] if the quantum theory is used to recalculate the probabilities. Next, the quantum mechanical probabilities are modified by the decoherence approach, which enables the initial state to factorize spontaneously. In this way we get a lower limit for the decoherence parameter , which measures the degree of decoherence. This result is compared with the experimental value [2, 3] of the decoherence parameter deduced from the data of the CPLEAR experiment [4]. 相似文献
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Summary The suitability of laser Raman spectrometry in process control is demonstrated by comparing results obtained under standard measuring conditions and with special optical fibers. The applicability of capillary tubes which can improve sensitivity in remote sensing is investigated and possible distortions of Raman spectra sampled with optical fibers are described. In preliminary experiments with U(VI) solutions it could be shown that internal standardization using the 1650 cm–1 water band is possible in the process control of aqueous solutions. 相似文献
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38.
Silica monoliths modified with trans-(1S,2S)-2-(N-4-allyloxy-3,5-dichlorobenzoyl)amino cyclohexanesulfonic acid were tested for enantioselective separations of various chiral bases by aqueous and nonaqueous CEC as well as nano-HPLC. The optimization of the immobilization procedure showed that an intermediate selector (SO) coverage, as does result from a single static immobilization cycle in the capillary at 60 degrees C with an 8% (m/v) SO solution in methanol, affords maximal EOF and optimal enantioselectivity values, while a second immobilization cycle does not lead to any improvements. Furthermore, the mobile phase composition was examined regarding the effectiveness of aqueous phases (ACN/water and methanol/water) compared to nonaqueous eluents (ACN/methanol) in terms of separation selectivity and efficiency. Additionally, different acids of varying strengths were tested as co-ions in the ion-exchange process, including formic acid, acetic acid, methanesulfonic acid, and TFA (pK(a) from 4.75 to 0.5). It turned out that the effects regarding EOF and enantioselectivity were largely negligible. The chromatographic efficiencies of the new capillary columns were compelling and remarkable for bases. H-u curves established for mefloquine revealed a C-term contribution (resistance to mass transfer) by a factor of about six lower in CEC than in nano-HPLC and an A-term (flow maldistribution) about three times lower in the CEC mode. Theoretical plate heights as low as around 3-5 mum could be obtained in CEC over a wide flow range (0.5-1.5 mm/s). Run-to-run repeatabilities like in HPLC and excellent system stability promise the practical usefulness of the novel monolithic capillary column for enantiomeric composition analysis of pharmaceuticals by CEC. 相似文献
39.
Fabrizio Colombo Jonathan Gantner Tim Janssens 《Mathematical Methods in the Applied Sciences》2016,39(18):5582-5606
In this paper, we introduce the Schatten class and the Berezin transform of quaternionic operators. The first topic is of great importance in operator theory, but it is also necessary to study the second one, which requires the notion of trace class operators, a particular case of the Schatten class. Regarding the Berezin transform, we give the general definition and properties. Then we concentrate on the setting of weighted Bergman spaces of slice hyperholomorphic functions. Our results are based on the S‐spectrum of quaternionic operators, which is the notion of spectrum that appears in the quaternionic version of the spectral theorem and in the quaternionic S‐functional calculus. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
40.
A series of different N-heterocyclic carbenes (NHCs) were reacted with 3,6-bis(3',5'-dimethylpyrazolyl)-tetrazine in the presence of an inorganic carbonate to provide access to a hitherto unprecedented compound class. The formed tetrazine derivatives bearing the NHC in the 3-position and an oxygen in the 6-position show a quinoidal-like structure, according to physical examinations and X-ray crystallography. 相似文献