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111.
Let T f be a Toeplitz operator on the Segal–Bargmann space or the standard weighted Bergman space over a bounded symmetric domain \({\Omega \subset {\bf C}^n}\) with possibly unbounded symbol f. Combining recent results in Bauer et al. (J. Funct. Anal. 259:57–78, 2010), Bauer et al. (J. reine angew. Math. doi: 10.1515/crelle-2015-0016), Issa (Integr. Equ. Oper. Theory 70:569–582, 2011) we show that in the case of uniformly continuous symbols f with respect to the Euclidean metric on C n and the Bergman metric on \({\Omega}\), respectively, the operator T f is bounded if and only if f is bounded. Moreover, T f is compact if and only if f vanishes at the boundary of \({\Omega.}\) This observation substantially extends a result in Coburn (Indiana Univ. Math. J. 23:433–439, 1973). 相似文献
112.
A Novel Bismuth‐Based Metal–Organic Framework for High Volumetric Methane and Carbon Dioxide Adsorption 下载免费PDF全文
Mathew Savage Dr. Sihai Yang Dr. Mikhail Suyetin Prof. Dr. Elena Bichoutskaia Dr. William Lewis Prof. Dr. Alexander J. Blake Sarah A. Barnett Prof. Dr. Martin Schröder 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(26):8024-8029
Solvothermal reaction of H4L (L=biphenyl‐3,3′,5,5′‐tetracarboxylate) and Bi(NO3)3 ? (H2O)5 in a mixture of DMF/MeCN/H2O in the presence of piperazine and nitric acid at 100 °C for 10 h affords the solvated metal–organic polymer [Bi2(L)1.5(H2O)2] ? (DMF)3.5 ? (H2O)3 (NOTT‐220‐solv). A single crystal X‐ray structure determination confirms that it crystallises in space group P2/c and has a neutral and non‐interpenetrated structure comprising binuclear {Bi2} centres bridged by tetracarboxylate ligands. NOTT‐220‐solv shows a 3,6‐connected network having a framework topology with a {4 ? 62}2{42 ? 65 ? 88}{62 ? 8} point symbol. The desolvated material NOTT‐220a shows exceptionally high adsorption uptakes for CH4 and CO2 on a volumetric basis at moderate pressures and temperatures with a CO2 uptake of 553 g L?1 (20 bar, 293 K) with a saturation uptake of 688 g L?1 (1 bar, 195 K). The corresponding CH4 uptake was measured as 165 V(STP)/V (20 bar, 293 K) and 189 V(STP/V) (35 bar, 293 K) with a maximum CH4 uptake for NOTT‐220a recorded at 20 bar and 195 K to be 287 V(STP)/V, while H2 uptake of NOTT‐220a at 20 bar, 77 K is 42 g L?1. These gas uptakes have been modelled by grand canonical Monte Carlo (GCMC) and density functional theory (DFT) calculations, which confirm the experimental data and give insights into the nature of the binding sites of CH4 and CO2 in this porous hybrid material. 相似文献
113.
The Ketimide Ligand is Not Just an Inert Spectator: Heteroallene Insertion Reactivity of an Actinide–Ketimide Linkage in a Thorium Carbene Amide Ketimide Complex 下载免费PDF全文
Dr. Erli Lu Dr. William Lewis Prof. Alexander J. Blake Prof. Stephen T. Liddle 《Angewandte Chemie (International ed. in English)》2014,53(35):9356-9359
The ketimide anion R2C?N? is an important class of chemically robust ligand that binds strongly to metal ions and is considered ideal for supporting reactive metal fragments due to its inert spectator nature; this contrasts with R2N? amides that exhibit a wide range of reactivities. Here, we report the synthesis and characterization of a rare example of an actinide ketimide complex [Th(BIPMTMS){N(SiMe3)2}(N?CPh2)] [ 2 , BIPMTMS=C(PPh2NSiMe3)2]. Complex 2 contains Th?Ccarbene, Th? Namide and Th? Nketimide linkages, thereby presenting the opportunity to probe the preferential reactivity of these linkages. Importantly, reactivity studies of 2 with unsaturated substrates shows that insertion reactions occur preferentially at the Th? Nketimide bond rather than at the Th?Ccarbene or Th? Namide bonds. This overturns the established view that metal‐ketimide linkages are purely inert spectators. 相似文献
114.
Parks Conor D. Gaieb Zied Chiu Michael Yang Huanwang Shao Chenghua Walters W. Patrick Jansen Johanna M. McGaughey Georgia Lewis Richard A. Bembenek Scott D. Ameriks Michael K. Mirzadegan Tara Burley Stephen K. Amaro Rommie E. Gilson Michael K. 《Journal of computer-aided molecular design》2020,34(2):99-119
Journal of Computer-Aided Molecular Design - The Drug Design Data Resource (D3R) aims to identify best practice methods for computer aided drug design through blinded ligand pose prediction and... 相似文献
115.
Yasmine S. Zubi Bingqing Liu Yifan Gu Dipankar Sahoo Jared C. Lewis 《Chemical science》2022,13(5):1459
Visible light photocatalysis enables a broad range of organic transformations that proceed via single electron or energy transfer. Metal polypyridyl complexes are among the most commonly employed visible light photocatalysts. The photophysical properties of these complexes have been extensively studied and can be tuned by modifying the substituents on the pyridine ligands. On the other hand, ligand modifications that enable substrate binding to control reaction selectivity remain rare. Given the exquisite control that enzymes exert over electron and energy transfer processes in nature, we envisioned that artificial metalloenzymes (ArMs) created by incorporating Ru(ii) polypyridyl complexes into a suitable protein scaffold could provide a means to control photocatalyst properties. This study describes approaches to create covalent and non-covalent ArMs from a variety of Ru(ii) polypyridyl cofactors and a prolyl oligopeptidase scaffold. A panel of ArMs with enhanced photophysical properties were engineered, and the nature of the scaffold/cofactor interactions in these systems was investigated. These ArMs provided higher yields and rates than Ru(Bpy)32+ for the reductive cyclization of dienones and the [2 + 2] photocycloaddition between C-cinnamoyl imidazole and 4-methoxystyrene, suggesting that protein scaffolds could provide a means to improve the efficiency of visible light photocatalysts.Artificial metalloenzyme visible light photocatalysts possess enhanced optical properties and are competent towards single electron and energy transfer organic transformations. 相似文献
116.
William N. Setzer Shahrara Afshar Norman L. Burns Lucille A. Ferrante Amy M. Hester Edward J. Meehan Gregory J. Grant Saju M. Isaac Christopher P. Laudeman Charles M. Lewis Donald G. VanDerveer 《Heteroatom Chemistry》1990,1(5):375-387
The mesocyclic trithioethers, 1,4,7-trithiacyclodecane, 1,4,7-trithiacycloundecane, 1,4,8-trithiacycloundecane, and 1,5,9-trithiacyclododecane; the mesocyclic trithioether ketones, 1,4,7-trithiacyclodecan-9-one; 1,4,8-trithiacycloundecan-6-one, and 1,5,9-trithiacyclododecan-3-one; and the mesocyclic trithioether alcohols, 1,4,7-trithiacyclodecan-9-ol, 1,4,8-trithiacycloundecan-6-ol, and 1,5,9-trithiacyclododecan-3-ol, have been synthesized using the cesium dithiolate technique. In some cases, the corresponding macrocyclic hexathioether was isolated from the reaction mixture in addition to the mesocyclic trithioether; 1,4,7,11,14,17-hexathiacycloeicosane, 1,4,7,11,14,17-hexathiacycloeicosan-9,19-dione, 1,4,7,12,15,18-hexathiacyclodocosane, and 1,5,9,13,17,21-hexathiacyclotetracosane. Single-crystal X-ray structures have been determined for 1,5,9-trithiacyclododecan-3-ol and 1,4,7,12,15,18-hexathiacyclodocosane. For 1,5,9-trithiacyclododecane-3-ol, the compound crystallizes in the monoclinic space group, C2/c, with a = 10.5926( 9 ) Å, b = 15.582(2) Å, c = 13.6015(8) Å, β = 98.186(6)0, Z = 8, and R = 0.038. The macrocycle, 1,4,7,12,15,18-hexathiacyclodocosane, crystallizes in the orthorhombic space group, Pbca, with a = 21.406(5) Å, b = 9.810(2) Å, c = 10.225(2) Å, Z = 4, and R = 0.020. 相似文献
117.
The problem of phase change in the presence of natural convection has been investigated. A model has been proposed based on the treatment of the release/absorption of latent heat as a heat source/sink in combination with the standard Galerkin finite element method with a primitive variable formulation on a fixed grid. To demonstrate the capabilities of the model, three cases of phase change of an aluminium alloy in the presence of natural convection arc considered, i.e. solidification, melting and combined solidification and melting. The solidification of water in a square cavity is modelled as another example, taking into account the density extremum, and the results are compared with a previously published work. 相似文献
118.
Transport in Porous Media - We develop an analytical model describing the flow of NaCl– $$\hbox {H}_2\hbox {O}$$ in a saturated porous medium adjacent to a hot vertical wall and apply the... 相似文献
119.
120.
Gas hydrate single-crystal structure analyses 总被引:4,自引:0,他引:4
Kirchner MT Boese R Billups WE Norman LR 《Journal of the American Chemical Society》2004,126(30):9407-9412
The first single-crystal diffraction studies on methane, propane, methane/propane, and adamantane gas hydrates SI, SII, and SH have been performed. To circumvent the problem of very slow crystal growth, a novel technique of in situ cocrystallization of gases and liquids resulting in oligocrystalline material in a capillary has been developed. With special data treatment, termed oligo diffractometry, structural data of the gas hydrates of methane, acetylene, propane, a propane/ethanol/methane-mixture and an adamantane/methane-mixture were obtained. Cell parameters are in accord with reported values. Host network and guest are subject to extensive disorder, reducing the reliability of structural information. It was found that most cages are fully occupied by a guest molecule with the exception of the dodecahedral cage in the acetylene hydrate which is only filled to 60%. For adamantane in the icosahedral cage a disordered model is proposed. 相似文献