共查询到20条相似文献,搜索用时 334 毫秒
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Dr. Shenglai Yao Dr. Peter Hrobárik Dipl.‐Chem. Florian Meier Dipl.‐Chem. Robert Rudolph Dr. Eckhard Bill Dr. Elisabeth Irran Prof. Dr. Martin Kaupp Prof. Dr. Matthias Driess 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(4):1246-1253
A unique heterobimetallic disulfur monoradical, complex 2 , with a diamond‐shaped {NiS2Pt} core has been synthesized by two‐electron reduction of a supersulfido‐(nacnac)nickel(II) complex (nacnac=β‐diketiminato) with [Pt(Ph3P)2(η2‐C2H4)] as a platinum(0) source and isolated in 82 % yield. Strikingly, the results of DFT calculations in accordance with spectroscopic (EPR, paramagnetic NMR) and structural features of the complex revealed that the bonding situation of the S2 ligand is between the elusive “half‐bonded” S2 radical trianion (${{\rm S}{{{{\bullet}}3- \hfill \atop 2\hfill}}}$ ) and two separated S2? ligands. Accordingly, the NiII center is partially oxidized, whereas the PtII site is redox innocent. The complex can be reversibly oxidized to the corresponding Ni,Pt‐disulfido monocation, compound 3 , with a S? S single bond, and reacts readily with O2 to form the corresponding superoxonickel(II) and disulfidoplatinum(II) ( 4 ) complexes. These compounds have been isolated in crystalline form and fully characterized, including IR and multi‐nuclear NMR spectroscopy as well as ESI mass spectrometry. The molecular structures of compounds 2 – 4 have been confirmed by single‐crystal X‐ray crystallography. 相似文献
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A solid‐state electrochemiluminescence (ECL) biosensor based on special ferrocene‐labeled molecular beacon (Fc‐MB) for highly sensitive detection of promyelocytic leukemia/retinoic acid receptor alpha (PML/RARα) fusion gene was developed successfully using Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$ /2‐(dibutylamino)ethanol (DBAE) as detecting pattern. Such a special sensor involves two main parts, an ECL substrate and an ECL intensity switch. The ECL substrate was made by modifying the complex of Ruthenium (II) tris‐(bipyridine) and Au nanoparticles (Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$ ‐AuNPs) onto the Au electrode (AuE) surface. The molecular beacon probe in which the ferrocene tag could effectively quench the ECL of the Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$ acted as ECL intensity switch. The molecular beacon probe was designed with special base sequence, which could hybridize with its complementary target DNA. In the absence of a target, the hairpin structure of the probe forced the ferrocene (Fc) into close proximity with the ECL substrate, thus reducing ECL intensity. Target binding allowed the Fc away from the ECL substrate and resulted in an obvious increment in ECL intensity due to the decreased Fc quenching effect. The effect of the amount of Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$ and the mixing procedure of Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$ and AuNPs solution on the fabrication of ECL film had been investigated. As a result, the change of ECL intensity had a direct relationship with the logarithm of PML/RARα fusion gene concentration in the range of 0.05–500 pM with a detection limit of 7 fM, and the developed biosensor possessed good molecular recognizability in human serum. Thus, the approach holds promise for the early diagnostics and prognosis monitoring of APL and other diseases. 相似文献
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The γ-distonic radical ions R$ \mathop {\rm O}\limits^ + $CHR′CH2?HR″ and their molecular ion counterparts R$ \mathop {\rm O}\limits^{{\rm + } \cdot } $CHR′CH2CH2R″ have been studied by isotopic labelling and collision-induced dissociation, applying a potential to the collision cell in order to separate activated from spontaneous decompositions. The stability of CH3$ \mathop {\rm O}\limits^ + $HCH(CH3)CH2?HCH3, C2H5$ \mathop {\rm O}\limits^ + $HCH(CH3)CH2?HCH3, CH3$ \mathop {\rm O}\limits^ + $HCH(CH3)CH2?H2, CH3$ \mathop {\rm O}\limits^ + $HCH2CH2?HCH3 and C2H5$ \mathop {\rm O}\limits^ + $HCH2CH2?HCH3, has been demonstrated and their characteristic decomposition, alcohol loss, identified. For all these γ-distonic ions, the 1,4-H abstraction leading to their molecular ion counterpart exhibits a primary isotope effect. 相似文献
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《Electroanalysis》2006,18(10):993-1000
A composite film modified electrode containing a Keggin‐type heteropolyanion, H3(PMo12O40)?H2O, was fabricated with 3‐aminopropyltrimethoxysilane (APMS) attached on an electrochemically activated glassy carbon (GC) electrode through the formation of C? O? Si bond. PMo12O was then complexed with APMS through the electrostatic interaction between the phosphate groups of PMo12O and amine groups of APMS (PMo12O ‐APMS). XPS and cyclic voltammetry were employed for characterization of the composite film. The PMo12O ‐APMS modified electrode showed three reversible redox pairs with smaller peak‐separation and was stable in the larger pH range compared with that in a solution phase. The catalytic properties of the modified electrode for the reduction of ClO , BrO , and IO were studied and the modified electrode exhibited good electrocatalytic activities for the three anions. The experimental parameters, such as pH, temperature, and the applied potential were optimized. The detection limits were determined to be 7.0±0.35 μM, 4.0±0.17 μM, and 0.1±0.04 μM for ClO , BrO , and IO , respectively. The modified electrode was applied to natural water samples for the detection of ClO , BrO , and IO . 相似文献
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J Prinz R Gaspari CA Pignedoli J Vogt P Gille M Armbrüster H Brune O Gröning D Passerone R Widmer 《Angewandte Chemie (International ed. in English)》2012,51(37):9339-9343
Scratching the surface: The high selectivity of PdGa catalysts towards the partial hydrogenation of acetylene was previously attributed to the separation of Pd atomic sites at the surfaces. The atomic structures of PdGa surfaces are determined by means of a combined experimental and computational approach, allowing investigation of the catalytic dissociation of hydrogen. The two opposite (111) and ${{\left( {\bar 1\bar 1\bar 1} \right)}}$ surfaces show a very different arrangement of catalytic centers. 相似文献
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Gamma Ray Radiation Effect on \begin{document}$\rm{{Bi}}_{2}$\end{document} W\begin{document}$\rm{{O}}_{6}$\end{document} Photocatalyst 下载免费PDF全文
The development of \begin{document}$\rm{Bi}_2$\end{document} W\begin{document}$\rm{O}_6$\end{document} -based materials has become one of research hotspots due to the increasing demands on high-efficient photocatalyst responding to visible light. In this work, the effect of high energy radiation (\begin{document}$\gamma$\end{document} -ray) on the structure and the photocatalytic activity of \begin{document}$\rm{Bi}_2$\end{document} W\begin{document}$\rm{O}_6$\end{document} nanocrystals was first studied. No morphological change of \begin{document}$\rm{Bi}_2$\end{document} W\begin{document}$\rm{O}_6$\end{document} nanocrystals was observed by SEM under \begin{document}$\gamma$\end{document} -ray radiation. However, the XRD spectra of the irradiated \begin{document}$\rm{Bi}_2$\end{document} W\begin{document}$\rm{O}_6$\end{document} nanocrystals showed the characteristic 2\begin{document}$\theta$\end{document} of (113) plane shifts slightly from 28.37\begin{document}$^{\rm{o}}$\end{document} to 28.45\begin{document}$^{\rm{o}}$\end{document} with the increase of the absorbed dose, confirming the change in the crystal structure of \begin{document}$\rm{Bi}_2$\end{document} W\begin{document}$\rm{O}_6$\end{document} . The XPS results proved the crystal structure change was originated from the generation of oxygen vacancy defects under high-dose radiation. The photocatalytic activity of \begin{document}$\rm{Bi}_2$\end{document} W\begin{document}$\rm{O}_6$\end{document} on the decomposition of methylene blue (MB) in water under visible light increases gradually with the increase of absorbed dose. Moreover, the improved photocatalytic performance of the irradiated \begin{document}$\rm{Bi}_2$\end{document} W\begin{document}$\rm{O}_6$\end{document} nanocrystals remained after three cycles of photocatalysis, indicating a good stability of the created oxygen vacancy defects. This work gives a new simple way to improve photocatalytic performance of \begin{document}$\rm{Bi}_2$\end{document} W\begin{document}$\rm{O}_6$\end{document} through creating oxygen vacancy defects in the crystal structure by \begin{document}$\gamma$\end{document} -ray radiation. 相似文献
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《Electroanalysis》2003,15(2):145-150
Nanomolar concentrations of dissolved sulfide have been observed in O2‐ bearing natural waters. The sulfide consists of oxidation‐resistant, unknown chemical components that might include metal‐sulfide complexes, elemental sulfur in various forms or organic sulfur compounds. Here we show that thioanions are also plausible components. Tetrathiomolybdate and tetrathioantimonate ions deposit respectively 3 and 4 equivalents of HgS at mercury electrodes. In cathodic stripping voltammetry, a common method to quantify nanomolar sulfide in nature, MoS and SbS would therefore contribute to “total dissolved sulfide.” Limited evidence suggests that thioanions may be powerful complexing agents that would be capable of affecting trace metal speciation and bioavailability in natural waters. 相似文献
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Intra- and Intermolecular Rovibrational States of HCl-H\begin{document}$ _\textbf{2} $\end{document} O and DCl-H\begin{document}$ _\textbf{2} $\end{document} O Dimers from Full-Dimensional and Fully Coupled Quantum Calculations 下载免费PDF全文