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231.
Caroline L. Foster Colin A. Kilner Mark Thornton‐Pett Malcolm A. Halcrow 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):319-320
In the title compound, [Cu(C20H24N2)2]BF4, the complex cation adopts a distorted tetrahedral structure, the dihedral angle between the least‐squares planes of the chelating ligand backbones being 51.1 (2)°. This flattening of the tetrahedral coordination sphere may be driven by the presence of intramolecular π–π stacking interactions between mesityl groups on adjacent ligands. 相似文献
232.
Dr. Stephanie A. Boer Dr. Keith F. White Benjamin Slater Adrian J. Emerson Dr. Gregory P. Knowles Dr. William A. Donald Dr. Aaron W. Thornton Prof. Bradley P. Ladewig Dr. Toby D. M. Bell Prof. Matthew R. Hill Prof. Alan L. Chaffee Prof. Brendan F. Abrahams Dr. David R. Turner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(36):8489-8493
A chiral, octahedral M12L12 cage, which is charge neutral and contains an internal void of about 2000 Å3, is reported. The cage was synthesised as an enantiopure complex by virtue of amino-acid-based dicarboxylate ligands, which assemble around copper paddlewheels at the vertices of the octahedron. The cage persists in solution with retention of the fluorescence properties of the parent acid. The solid-state structure contains large pores both within and between the cages, and displays permanent porosity for the sorption of gases with retention of crystallinity. Initial tests show some enantioselectivity of the cage towards guests in solution. 相似文献
233.
Dr. Cher Hon Lau Dr. Kristina Konstas Dr. Aaron W. Thornton Dr. Amelia C. Y. Liu Dr. Stephen Mudie Dr. Danielle F. Kennedy Dr. Shaun C. Howard Dr. Anita J. Hill Dr. Matthew R. Hill 《Angewandte Chemie (International ed. in English)》2015,54(9):2669-2673
Porosity loss, also known as physical aging, in glassy polymers hampers their long term use in gas separations. Unprecedented interactions of porous aromatic frameworks (PAFs) with these polymers offer the potential to control and exploit physical aging for drastically enhanced separation efficiency. PAF‐1 is used in the archetypal polymer of intrinsic microporosity (PIM), PIM‐1, to achieve three significant outcomes. 1) hydrogen permeability is drastically enhanced by 375 % to 5500 Barrer. 2) Physical aging is controlled causing the selectivity for H2 over N2 to increase from 4.5 to 13 over 400 days of aging. 3) The improvement with age of the membrane is exploited to recover up to 98 % of H2 from gas mixtures with N2. This process is critical for the use of ammonia as a H2 storage medium. The tethering of polymer side chains within PAF‐1 pores is responsible for maintaining H2 transport pathways, whilst the larger N2 pathways gradually collapse. 相似文献
234.
A. Gunther M. Khoury S. Mili
i D. Vasileska T. Thornton S. M. Goodnick 《Superlattices and Microstructures》2000,27(5-6)
We report on the transport properties of novel Si quantum dot structures with controllable electron number through both top and side gates. Quantum dots were fabricated by a split-gate technique within a standard MOSFET process. Four-terminal dc electrical measurements were performed at 4.2 K in a liquid helium cryostat. Strong oscillations in the conductance through the dot are observed as a function of both the top gate bias and of the plunger bias. An overall monotonic and quasi-periodic movement of the peak conductance is observed which is believed to be associated with the bare level structure of the electronic states in the dot coupled with the Coulomb charging energy. Crossing behavior is observed as well, suggestive of either many-body effects or symmetry breaking of the dot states by the applied bias. 相似文献
235.
Paul D. Thornton Shah M. Reduwan Billah Neil R. Cameron 《Macromolecular rapid communications》2013,34(3):257-262
The generation of a range of star‐shaped block copolymers composed of a biocompatible poly(ethylene glycol) (PEG) core tethered to a polyalanine (PAla) shell that possesses the capability to (reversibly) self‐assemble in water is described. The hydrogels formed offer a hydrophilic environment ideal for biological processes involving proteins and are able to withhold albumin for prolonged periods before its triggered release following the targeted material degradation by the proteolytic enzyme elastase. Consequently, the materials formed offer significant promise for the delivery of proteins, and possibly inhibitors, in response to a proteolytic enzyme overexpressed in chronic wounds. 相似文献
236.
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238.
O. L. Barnebey R. M. Isham A. Rosenheim O. Schütte T. R. Ball G. Mc P. Smith J. Waddell W. Trautmann H. König Percy H. Walker W. M. Thornton Cathrein Ch. Grandjean A. Marinot Carnot Goutal Earl M. Anger A. Cavazzi F. Ferrari H. I. Winch V. L. Chandratreya E. Griffiths-Jones E. Blanck W. Geilmann Ch. E. Wait und L. E. Barton 《Fresenius' Journal of Analytical Chemistry》1924,65(9):367-376
Ohne Zusammenfassung 相似文献
239.
The impact of the quantum mechanical tunneling effect on the operation of MESFET device structure has been investigated. Due to the presence of a Schottky barrier in a highly doped semiconductor, the depletion region is so narrow that electrons can tunnel through the barrier and contribute to the gate leakage current. This, in turn, facilitates current gain of the Schottky junction transistor (SJT) in the subthreshold region. In a simulation of a SJT we have used 2D Monte Carlo particle-based simulations. Quantum mechanical tunneling effects have been accounted for by using the Airy function transfer matrix approach, valid for piecewise linear potential barriers. 相似文献
240.