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101.
Lize de Jager Benita Barton Eric C. Hosten 《Journal of inclusion phenomena and macrocyclic chemistry》2018,92(1-2):181-194
The behaviour of two closely related xanthone-derived host compounds, N,N’-bis(9-phenyl-9-xanthenyl)ethylenediamine and N,N′-bis(9-phenyl-9-thioxanthenyl)ethylenediamine, which formed complexes with CH2Cl2, CH2Br2 and CH2I2 after recrystallization from each of these solvents, was compared when subjected to these guest and guest mixtures in the vapour phase. Surprisingly, these hosts displayed entirely different behaviours under these conditions, with only the thioxanthenyl derivative possessing the ability to clathrate these guests (or guest mixtures) from the gas phase; this ability was entirely absent in the xanthenyl host. All novel complexes were subjected to single crystal diffraction analyses in order to investigate the interactions present, as well as thermal and Hirshfeld surface experiments. The host selectivity and host–guest interactions were correlated with the differences observed in the recrystallization and vapour experiments. Furthermore, data obtained for the novel complexes by employing various analytical techniques were related back to the observed selectivity order. 相似文献
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The site-specific recognition of abasic sites and single base bulges in duplex DNA by sterically expansive rhodium metalloinsertors has been investigated. Through DNA photocleavage experiments, Rh(bpy)2(chrysi)3+ is shown to bind both abasic sites and single base bulges site-specifically and, upon irradiation, to cleave the backbone of the defect-containing DNA. Photocleavage titrations reveal that the metal complex binds DNA containing an abasic site with high affinity (2.6(5) x 106 M-1), comparably to the metalloinsertor and a CC mismatch. The complex binds single base bulge sites with lower affinity (approximately 105 M-1). Analysis of cleavage products and the correlation of affinities with helix destabilization suggest that Rh(bpy)2(chrysi)3+ binds both lesions via metalloinsertion, as observed for Rh binding at mismatched sites, a binding mode in which the mismatched or unpaired bases are extruded from the helix and replaced in the base stack by the sterically expansive ligand of the metalloinsertor. 相似文献
104.
On‐Surface Domino Reactions: Glaser Coupling and Dehydrogenative Coupling of a Biscarboxylic Acid To Form Polymeric Bisacylperoxides 下载免费PDF全文
Philipp Alexander Held Dr. Hong‐Ying Gao Lacheng Liu Dr. Christian Mück‐Lichtenfeld Alexander Timmer Dr. Harry Mönig Dennis Barton Prof. Dr. Johannes Neugebauer Prof. Dr. Harald Fuchs Prof. Dr. Armido Studer 《Angewandte Chemie (International ed. in English)》2016,55(33):9777-9782
Herein we report the on‐surface oxidative homocoupling of 6,6′‐(1,4‐buta‐1,3‐diynyl)bis(2‐naphthoic acid) (BDNA) via bisacylperoxide formation on different Au substrates. By using this unprecedented dehydrogenative polymerization of a biscarboxylic acid, linear poly‐BDNA with a chain length of over 100 nm was prepared. It is shown that the monomer BDNA can be prepared in situ at the surface via on‐surface Glaser coupling of 6‐ethynyl‐2‐naphthoic acid (ENA). Under the Glaser coupling conditions, BDNA directly undergoes polymerization to give the polymeric peroxide (poly‐BDNA) representing a first example of an on‐surface domino reaction. It is shown that the reaction outcome varies as a function of surface topography (Au(111) or Au(100)) and also of the surface coverage, to give branched polymers, linear polymers, or 2D metal–organic networks. 相似文献
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Junjie Zhao Dennis T. Lee Robert W. Yaga Morgan G. Hall Heather F. Barton Ian R. Woodward Christopher J. Oldham Howard J. Walls Gregory W. Peterson Prof. Gregory N. Parsons 《Angewandte Chemie (International ed. in English)》2016,55(42):13224-13228
The threat associated with chemical warfare agents (CWAs) motivates the development of new materials to provide enhanced protection with a reduced burden. Metal–organic frame‐works (MOFs) have recently been shown as highly effective catalysts for detoxifying CWAs, but challenges still remain for integrating MOFs into functional filter media and/or protective garments. Herein, we report a series of MOF–nanofiber kebab structures for fast degradation of CWAs. We found TiO2 coatings deposited via atomic layer deposition (ALD) onto polyamide‐6 nanofibers enable the formation of conformal Zr‐based MOF thin films including UiO‐66, UiO‐66‐NH2, and UiO‐67. Cross‐sectional TEM images show that these MOF crystals nucleate and grow directly on and around the nanofibers, with strong attachment to the substrates. These MOF‐functionalized nanofibers exhibit excellent reactivity for detoxifying CWAs. The half‐lives of a CWA simulant compound and nerve agent soman (GD) are as short as 7.3 min and 2.3 min, respectively. These results therefore provide the earliest report of MOF–nanofiber textile composites capable of ultra‐fast degradation of CWAs. 相似文献
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A simple water soluble diselenide derivative 1 shows radical scavenger properties towards alkyl and hydroxyl radicals (k3 (0°C)=6.8×108 M−1 s−1) in Fenton-type chemistry. The reaction rate between produceded alkyl radicals 2 and the diselenide overwhelms self-termination and halogen transfer reactions. 相似文献
110.
I. E. Barton 《国际流体数值方法杂志》1997,25(6):633-644
The study investigates the entrance effect for flow over a backward-facing step by comparing predictions that set the inlet boundary at various locations upstream of the sudden expansion. Differences are most significant in the sudden expansion region. If the geometry has an inlet channel, then shorter reattachment and separation lengths are predicted. Comparisons with experimental data indicate that better agreement is found using a long inlet channel, but only for low Reynolds numbers where the experimental error is less significant. For certain cases, predictions with a high expansion number are perturbed by the entrance effect more than low-expansion-number predictions; however, the effect is localized in the sudden expansion region. Channels with low expansion numbers always experience a greater entrance effect after some distance upstream and downstream of the sudden expansion. The boundary layer growth in the inlet channel was examined using a uniform inlet velocity profile. © 1997 John Wiley & Sons, Ltd. 相似文献