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1.
A Series of Diamagnetic Pyridine Monoimine Rhenium Complexes with Different Degrees of Metal‐to‐Ligand Charge Transfer: Correlating 13C NMR Chemical Shifts with Bond Lengths in Redox‐Active Ligands 下载免费PDF全文
Dr. Daniel Sieh Prof. Dr. Clifford P. Kubiak 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(30):10638-10650
A set of pyridine monoimine (PMI) rhenium(I) tricarbonyl chlorido complexes with substituents of different steric and electronic properties was synthesized and fully characterized. Spectroscopic (NMR and IR) and single‐crystal X‐ray diffraction analyses of these complexes showed that the redox‐active PMI ligands are neutral and that the overall electronic structure is little affected by the choices of the substituent at the ligand backbone. One‐ and two‐electron reduction products were prepared from selected starting compounds and could also be characterized by multiple spectroscopic methods and X‐ray diffraction. The final product of a one‐electron reduction in THF is a diamagnetic metal–metal‐bonded dimer after loss of the chlorido ligand. Bond lengths in and NMR chemical shifts of the PMI ligand backbone indicate partial electron transfer to the ligand. Two‐electron reduction in THF also leads to the loss of the chlorido ligand and a pentacoordinate complex is obtained. The comparison with reported bond lengths and 13C NMR chemical shifts of doubly reduced free pyridine monoaldimine ligands indicates that both redox equivalents in the doubly reduced rhenium complex investigated here are located in the PMI ligand. With diamagnetic complexes varying over three formal reduction stages at the PMI ligand we were, for the first time, able to establish correlations of the 13C NMR chemical shifts with the relevant bond lengths in redox‐active ligands over a full redox series. 相似文献
2.
We present an abstract characterization of various types of Menger algebras of n-place functions allowing certain permutations of variables. 相似文献
3.
Reduction of phenyl-substituted pyridinium methoiodides with sodium borohydride in water afforded besides the desired tetrahydropyridines substantial amounts of amine-borane complexes. Reduction in methanol afforded tetrahydropyridines in high yield, with almost no amine-boranes formed. 相似文献
4.
Martowicz Adam Bryła Jakub Staszewski Wieslaw J. Ruzzene Massimo Uhl Tadeusz 《Nonlinear dynamics》2019,97(3):1911-1935
Nonlinear Dynamics - The work is primarily devoted to the peridynamic model elaborated for a solid body made of shape memory alloys (SMAs). The superelasticity effect is taken into consideration as... 相似文献
5.
R. Kubiak T. Muller T. Maurer K. W. Eichhorn 《International journal of environmental analytical chemistry》2013,93(1-4):349-358
Abstract Comparative volatilization experiments were carried out using isoproturon and parathion-methyl sprayed on French beans in field experiments and on plant stands (0.5 m2) in the volatilization chamber developed by the SLFA Neustadt using both compounds 14C-labelled. The experimental conditions in the field experiments concerning wind speed, temperature and humidity fluctuations were simulated in the volatilization chamber. The laboratory experiment reflected the actual outdoor situation, showing only a negligible amount of volatile isoproturon directly measured in air samples, and providing no reduction of the A.I. residues in plants compared with the initial value in the corresponding field experiment. 77.2% of the parathion-methyl applied to the plants were volatilized and measured directly in air samples in the volatilization chamber while a reduction by 74.7% was found for the corresponding field experiment by residue analysis of the plants after 24 h. No details could be given concerning the nature of the evaporated portions in the field experiment. 相似文献
6.
We give an abstract characterization of algebras of partial functions from A n to A endowed with the operations of the Menger superposition and the set-theoretic difference of functions as subsets of A n+1. 相似文献
7.
8.
The aim of this work was construction of the new wavelet function and verification that a continuous wavelet transform with a specially defined dedicated mother wavelet is a useful tool for precise detection of end-point in a potentiometric titration. The proposed algorithm does not require any initial information about the nature or the type of analyte and/or the shape of the titration curve. The signal imperfection, as well as random noise or spikes has no influence on the operation of the procedure.The optimization of the new algorithm was done using simulated curves and next experimental data were considered. In the case of well-shaped and noise-free titration data, the proposed method gives the same accuracy and precision as commonly used algorithms. But, in the case of noisy or badly shaped curves, the presented approach works good (relative error mainly below 2% and coefficients of variability below 5%) while traditional procedures fail. Therefore, the proposed algorithm may be useful in interpretation of the experimental data and also in automation of the typical titration analysis, specially in the case when random noise interfere with analytical signal. 相似文献
9.
Damian Kubiak 《Journal of Mathematical Analysis and Applications》2009,349(1):291-296
The condition δ2 in Cesàro-Orlicz sequence spaces equipped with the Luxemburg norm is discussed. The comparison theorem for these spaces is presented. Some counterexamples are provided. 相似文献
10.