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1.
KL Britton HF Rogers Y Asano T Dairi Y Kato TJ Stillman DW Rice 《Acta crystallographica. Section D, Biological crystallography》1998,53(4):124-126
The novel NAD+-linked opine dehydrogenase from a soil isolate Arthrobacter sp. strain 1C belongs to an enzyme superfamily whose members exhibit quite diverse substrate specificites. Crystals of this opine dehydrogenase, obtained in the presence or absence of co-factor and substrates, have been shown to diffract to beyond 1.8 ? resolution. X-ray precession photographs have established that the crystals belong to space group P21212, with cell parameters a = 104.9, b = 80.0, c = 45.5 ? and a single subunit in the asymmetric unit. The elucidation of the three-dimensional structure of this enzyme will provide a structural framework for this novel class of dehydrogenases to enable a comparison to be made with other enzyme families and also as the basis for mutagenesis experiments directed towards the production of natural and synthetic opine-type compounds containing two chiral centres. 相似文献
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Prof. Polly L. Arnold Dr. Alessandro Prescimone Dr. Joy H. Farnaby Dr. Stephen M. Mansell Prof. Simon Parsons Prof. Nikolas Kaltsoyannis 《Angewandte Chemie (International ed. in English)》2015,54(23):6735-6739
The diuranium(III) compound [UN′′2]2(μ‐η6:η6‐C6H6) (N′′=N(SiMe3)2) has been studied using variable, high‐pressure single‐crystal X‐ray crystallography, and density functional theory . In this compound, the low‐coordinate metal cations are coupled through π‐ and δ‐symmetric arene overlap and show close metal? CH contacts with the flexible methyl CH groups of the sterically encumbered amido ligands. The metal–metal separation decreases with increasing pressure, but the most significant structural changes are to the close contacts between ligand CH bonds and the U centers. Although the interatomic distances are suggestive of agostic‐type interactions between the U and ligand peripheral CH groups, QTAIM (quantum theory of atoms‐in‐molecules) computational analysis suggests that there is no such interaction at ambient pressure. However, QTAIM and NBO analyses indicate that the interaction becomes agostic at 3.2 GPa. 相似文献
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Polly L. Arnold Alessandro Prescimone Joy H. Farnaby Stephen M. Mansell Simon Parsons Nikolas Kaltsoyannis 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(23):6839-6843
The diuranium(III) compound [UN′′2]2(μ‐η6:η6‐C6H6) (N′′=N(SiMe3)2) has been studied using variable, high‐pressure single‐crystal X‐ray crystallography, and density functional theory . In this compound, the low‐coordinate metal cations are coupled through π‐ and δ‐symmetric arene overlap and show close metal CH contacts with the flexible methyl CH groups of the sterically encumbered amido ligands. The metal–metal separation decreases with increasing pressure, but the most significant structural changes are to the close contacts between ligand CH bonds and the U centers. Although the interatomic distances are suggestive of agostic‐type interactions between the U and ligand peripheral CH groups, QTAIM (quantum theory of atoms‐in‐molecules) computational analysis suggests that there is no such interaction at ambient pressure. However, QTAIM and NBO analyses indicate that the interaction becomes agostic at 3.2 GPa. 相似文献
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Stephen M. Mansell Michael Green Richard J. Kilby Martin Murray Christopher A. Russell 《Comptes Rendus Chimie》2010,13(8-9):1073-1081
Me3SiCP may be prepared by dehydrochlorination of Me3SiCH2PCl2 at room temperature in aromatic solvents using DABCO in the presence of AgOTf. Reaction of Me3SiCP with a selection of s-block metals, s-block metal salts and ytterbium effects conversion to a mixture of di- and triphospholide anions. This mixture of anions was subsequently reacted with FeCl2 to yield a mixture of tetra-, penta- and hexaphosphaferrocenes. 相似文献
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Wonsook Ha Robert S. Mansell Dilip Shinde Nam-Ho Kim Husein A. Ajwa Craig D. Stanley 《Transport in Porous Media》2009,78(1):77-99
Pre-plant application of toxic fumigants to soil beds covered by plastic film is commonly used in agriculture to control soil-borne
pathogens. Plastic mulch covers tend to physically suppress the emissive loss of gaseous fumigant to the atmosphere. When
liquid fumigant metham sodium (MS) is applied in irrigation water to field soil, it is rapidly transformed to the gaseous
methyl isothiocyanate (MITC). The gaseous MITC is a potential atmospheric contaminant, and any untransformed MS is a potential
contaminant of underlying groundwater due to the high water solubility of MS. A finite element numerical model was developed
to investigate two-dimensional MITC fate/transport under non-isothermal soil conditions. Directional solar heating on soil
beds, coupled heat and water flow in the soil, and non-isothermal chemical transport were included in the model. Field soil
data for MITC distribution, soil water content, meteorological data, and laboratory data were used to verify the model for
soil beds covered with plastic mulch. Four possible scenarios were considered: low and high drip-irrigation rates and low
and high water contents. The movement of the center of MITC mass in the soil profile was effectively simulated. The lower
drip-irrigation rate of MS yielded more extensive coverage of MITC in the plastic-covered soil bed. The lower soil air contents
due to higher soil water contents for the higher irrigation rate resulted in high concentrations of soil MITC. NRMSE (normalized
root mean square error) calculations further verified that the model predicted fumigant fate/transport well under these non-isothermal
field conditions. 相似文献
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Mansell D Rattray N Etchells LL Schwalbe CH Blake AJ Bichenkova EV Bryce RA Barker CJ Díaz A Kremer C Freeman S 《Chemical communications (Cambridge, England)》2008,(41):5161-5163
Natural myo-inositol phosphate antioxidants containing the 1,2,3-trisphosphate motif bind Fe(3+) in the unstable penta-axial conformation. 相似文献
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The synthesis and X-ray crystal structures of five N-heterocyclic stannylenes are reported. These compounds, containing a variety of backbones, were prepared by the salt metathesis of the appropriate dilithiated diamide with SnCl(2) and show a high degree of thermal stability compared to the corresponding species with unsaturated backbones. If bulky diisopropylphenyl groups are attached to the nitrogen centers then the structures are monomeric, but when the less bulky mesityl groups are employed the solid-state structure was shown to be dimeric. 相似文献
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Interplay of spin–orbit coupling and superconducting correlations in germanium telluride thin films 下载免费PDF全文
Vijay Narayan Thuy‐Anh Nguyen Rhodri Mansell David Ritchie Gregor Mussler 《固体物理学:研究快报》2016,10(3):253-259
There is much current interest in combining superconductivity and spin–orbit coupling in order to induce the topological superconductor phase and associated Majorana‐like quasiparticles which hold great promise towards fault‐tolerant quantum computing. Experimentally these effects have been combined by the proximity‐coupling of super‐conducting leads and high spin–orbit materials such as InSb and InAs, or by controlled Cu‐doping of topological insu‐lators such as Bi2Se3. However, for practical purposes, a single‐phase material which intrinsically displays both these effects is highly desirable. Here we demonstrate coexisting superconducting correlations and spin–orbit coupling in molecular‐beam‐epitaxy‐grown thin films of GeTe. The former is evidenced by a precipitous low‐temperature drop in the electrical resistivity which is quelled by a magnetic field, and the latter manifests as a weak antilocalisation (WAL) cusp in the magnetotransport. Our studies reveal several other intriguing features such as the presence of two‐dimensional rather than bulk transport channels below 2 K, possible signatures of topological superconductivity, and unexpected hysteresis in the magnetotransport. Our work demonstrates GeTe to be a potential host of topological SC and Majorana‐like excitations, and to be a versatile platform to develop quantum information device architectures. (© 2016 The Authors. Phys. Status Solidi RRL published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
10.
Xie X Haddow MF Mansell SM Norman NC Russell CA 《Chemical communications (Cambridge, England)》2011,47(13):3748-3750
The new polycyclic borazines B(2){1,2-N(2)C(6)H(4)}(2){B(2)(NMe(2))(2)}(2), B(2){1,8-N(2)naph}(2){B(2)(NMe(2))(2)}(2) and B(2)(NPh)(4){B(2)(NMe(2))(2)}(2) have been prepared from diborate(4) anions and two equivalents of B(2)Cl(2)(NMe(2))(2) and have been structurally characterised. Aspects of their structure and bonding are discussed and comparison made with corresponding polycyclic aromatic hydrocarbons. 相似文献