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351.
Stamatatos TC Poole KM Foguet-Albiol D Abboud KA O'Brien TA Christou G 《Inorganic chemistry》2008,47(15):6593-6595
The S = 11 ground states of the Mn 7 family of mixed-valence complexes with a metal-centered hexagonal topology have been found by density functional theory calculations to arise by spin frustration involving small differences in the magnitudes of the two weakest interactions controlling the alignment of the central spin. Targeted structural perturbation has allowed a complex with the central spin flipped to be discovered, which thus possesses the maximum S = 16 ground state. 相似文献
352.
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354.
Identification of emissive lanthanide complexes suitable for cellular imaging that resist quenching by endogenous anti-oxidants 总被引:1,自引:0,他引:1
Poole RA Montgomery CP New EJ Congreve A Parker D Botta M 《Organic & biomolecular chemistry》2007,5(13):2055-2062
Excited state quenching by urate and ascorbate of selected europium and terbium(III) macrocyclic complexes has been assessed and related to the ease of complex visualisation by optical microscopy inside various living cells, e.g. CHO, COS and NIH 3T3. It is the relative insensitivity of certain sterically encumbered complexes to dynamic quenching by urate that favours their usage for in cellulo applications. Non-covalent binding of the complex by protein also shields the excited lanthanide(III) ion from collisional quenching; this effect is most marked for a cationic triamide complex, [Ln.1](3+), consistent with its ease of visualisation by luminescence microscopy. 相似文献
355.
Qian J Wani R Klomsiri C Poole LB Tsang AW Furdui CM 《Chemical communications (Cambridge, England)》2012,48(34):4091-4093
β-ketoesters are robust probes for labeling sulfenic acid (-SOH) proteins allowing quantitative cleavage of the tag for improved analysis of the labeled peptides by MS. 相似文献
356.
The solvation parameter model is used to characterize the separation properties of the polar stationary phases EC-Wax and PAG with a poly(ethylene oxide) backbone (substituted with propylene oxide in the case of PAG) and the cyanopropyl-substituted polysilphenylene-siloxane stationary phase BPX90 at five equally spaced temperatures between 60 and 140 degrees C. The separation characteristics of these stationary phases are compared to four PEG and two poly(cyanopropylsiloxane) stationary phases (HP-20M, HP-Innowax, SolGel-Wax, DB-WAXetr, HP-88, and SP-2340) characterized in the same way. The database of system constants for these polar stationary phases is used to provide insight into the separation mechanism for fatty acid methyl esters and to determine selectivity differences that can be expected for generically similar stationary phase types. The discussion is not structured to indicate which stationary phase should be used for a particular separation but to provide a general framework to demonstrate the relationship between the retention mechanism and stationary phase chemistry. 相似文献
357.
Alexander J. Patton Laura A. Poole‐Warren Rylie A. Green 《Macromolecular bioscience》2016,16(8):1103-1121
Traditionally, conductive materials for electrodes are based on high modulus metals or alloys. Development of bioelectrodes that mimic the mechanical properties of the soft, low modulus tissues in which they are implanted is a rapidly expanding field of research. Many polymers exist that more closely match tissue mechanics than metals; however, the majority do not conduct charge. Integrating conductive properties via incorporation of metals and other conductors into nonconductive polymers is a successful approach to producing polymers that can be used in electrical interfacing devices. When combining conductive materials with nonconductive polymer matrices, there is often a tradeoff between the electrical and mechanical properties. This review analyzes the advantages and disadvantages of approaches involving coating or layer formation, composite formation via dispersion of conductive inclusions through polymer matrices, and in situ growth of a conductive network within polymers.
358.
Chromatographic methods dominate the field of organic analysis. However, many samples are too dilute, too complex or incompatible with the chromatographic system to render separation or detection possible without preliminary matrix simplification and/or preconcentration. A broad selection of the most common, recent and emerging isolation, clean-up and concentration techniques used to prepare samples for chromatographic separations are reviewed. 相似文献
359.
Control over Electrochemical Water Oxidation Catalysis by Preorganization of Molecular Ruthenium Catalysts in Self‐Assembled Nanospheres 下载免费PDF全文
Dr. Fengshou Yu David Poole III Dr. Simon Mathew Dr. Ning Yan Joeri Hessels Nicole Orth Prof. Ivana Ivanović‐Burmazović Prof. Joost N. H. Reek 《Angewandte Chemie (International ed. in English)》2018,57(35):11247-11251
Oxygen formation through water oxidation catalysis is a key reaction in the context of fuel generation from renewable energies. The number of homogeneous catalysts that catalyze water oxidation at high rate with low overpotential is limited. Ruthenium complexes can be particularly active, especially if they facilitate a dinuclear pathway for oxygen bond formation step. A supramolecular encapsulation strategy is reported that involves preorganization of dilute solutions (10?5 m ) of ruthenium complexes to yield high local catalyst concentrations (up to 0.54 m ). The preorganization strategy enhances the water oxidation rate by two‐orders of magnitude to 125 s?1, as it facilitates the diffusion‐controlled rate‐limiting dinuclear coupling step. Moreover, it modulates reaction rates, enabling comprehensive elucidation of electrocatalytic reaction mechanisms. 相似文献
360.
The solvation parameter model is used to characterize the retention properties of the bis(cyanopropylsiloxane)-co-methylsilarylene, HP-88, and poly(siloxane), Rtx-440, stationary phases over the temperature range 60-140 degrees C. HP-88 is among the most cohesive, dipolar/polarizable and hydrogen-bond basic of stationary phases for open-tubular column gas chromatography. It has no hydrogen-bond acidity or capacity for electron lone pair interactions. It exhibits similar selectivity to the poly(cyanopropylsiloxane) stationary phase SP-2340. Rtx-440 is a low-polarity, low-cohesion stationary phase with a moderate capacity for dipolar/polarizable and hydrogen-bond base interactions. It has no hydrogen-bond acidity and possesses weak electron lone pair interactions. It has unique selectivity when compared against a system constants database for 28 common stationary phase compositions. Cluster analysis indicated that the poly(cyanopropylphenyldimethylsiloxane) stationary phase containing 6% cyanopropylphenylsiloxane monomer, DB-1301, the poly(dimethyldiphenylsiloxane) stationary phase containing 20% diphenylsiloxane monomer, Rtx-20, the poly(siloxane) stationary phase of unknown composition, DB-624, and DX-1 [a mixture of poly(dimethylsiloxane) and poly(ethylene glycol) 9:1] are the closest selectivity matches in the database. The selectivity of DB-1301 and Rtx-440 are very similar for solutes with weak hydrogen-bond acidity allowing one stationary phase to be substituted for the other with likely success. For strong hydrogen-bond acids, such as phenols, DB-1301 and Rtx-440 exhibit different selectivity. 相似文献