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401.
402.
Ilia Kochetygov Anita Justin Mehrdad Asgari Shuliang Yang Vikram Karve Till Schertenleib Dragos Stoian Emad Oveisi Mounir Mensi Wendy L. Queen 《Chemical science》2022,13(21):6418
Using azolium-based ligands for the construction of metal–organic frameworks (MOFs) is a viable strategy to immobilize catalytically active N-heterocyclic carbenes (NHC) or NHC-derived species inside MOF pores. Thus, in the present work, a novel copper MOF referred to as Cu-Sp5-BF4, is constructed using an imidazolinium ligand, H2Sp5-BF4, 1,3-bis(4-carboxyphenyl)-4,5-dihydro-1H-imidazole-3-ium tetrafluoroborate. The resulting framework, which offers large pore apertures, enables the post-synthetic modification of the C2 carbon on the ligand backbone with methoxide units. A combination of X-ray diffraction (XRD), solid-state nuclear magnetic resonance (ssNMR) and electron microscopy (EM), are used to show that the post-synthetic methoxide modification alters the dimensionality of the material, forming a turbostratic phase, an event that further improves the accessibility of the NHC sites promoting a second modification step that is carried out via grafting iridium to the NHC. A combination of X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) methods are used to shed light on the iridium speciation, and the catalytic activity of the Ir–NHC containing MOF is demonstrated using a model reaction, stilbene hydrogenation.A new MOF with a saturated N-heterocyclic carbene ligand undergoes a series of structural transformations to produce a turbostratic material, which serves as a better support for an iridium hydrogenation catalyst, when compared to the parent material. 相似文献
403.
Yarmoshenko Ilia Vasilyev Aleksey Ekidin Aleksey Pyshkina Maria Malinovsky Georgy Onishchenko Aleksandra Zhukovsky Michael 《Journal of Radioanalytical and Nuclear Chemistry》2021,328(2):727-737
Journal of Radioanalytical and Nuclear Chemistry - To control the specific activity of 226Ra in building materials of operated buildings, a non-destructive in situ method consisted in measurements... 相似文献
404.
Adriana Popa Lavinia Macarie Ecaterina S. Dragan Viorica Parvulescu Gheorghe Ilia 《International Journal of Polymer Analysis and Characterization》2020,25(6):457-466
Abstract The chlorometylated styrene–divinylbenzene copolymer with different percent of divinylbenzene (code: S-6.7 DVB, S-12DVB, and S-15DVB) was functionalized with 3-hydroxybenzaldehyde for obtaining intermediated polymers. The aminotrimethoxysilanphosphonate groups were grafted by one-pot reactions in tetrahydrofuran using three components: polymers grafted with aldehyde groups (code: CHO-6.7, CHO-12, and CHO-15), 3-aminopropyltrimethoxysilane, diethylphosphite. The aminotrimethoxysilanphosphonate groups functionalized onto styrene-(6.7, 12, and 15%) divinylbenzene copolymer (code: PAF-6.7, PAF-12, and PAF-15) and evolution of the reaction were evidenced by FT-IR spectroscopy and porous structure by N2 adsorption-desorption, SEM microscopy. The thermal behavior of aldehydes and materials: PAF-6.7, PAF-12, and PAF-15 are different than initial polymer supports. 相似文献
405.
Sergey A. Rzhevskiy Maxim A. Topchiy Vasilii N. Bogachev Lidiya I. Minaeva Ilia R. Cherkashchenko Konstantin V. Lavrov Grigorii K. Sterligov Mikhail S. Nechaev Andrey F. Asachenko 《Mendeleev Communications》2021,31(3):409-411
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406.
Matvey V. Kraposhin Matthias Banholzer Michael Pfitzner Ilia K. Marchevsky 《国际流体数值方法杂志》2018,88(2):79-99
This paper describes the implementation of a numerical solver that is capable of simulating compressible flows of nonideal single‐phase fluids. The proposed method can be applied to arbitrary equations of state and is suitable for all Mach numbers. The pressure‐based solver uses the operator‐splitting technique and is based on the PISO/SIMPLE algorithm: the density, velocity, and temperature fields are predicted by solving the linearized versions of the balance equations using the convective fluxes from the previous iteration or time step. The overall mass continuity is ensured by solving the pressure equation derived from the continuity equation, the momentum equation, and the equation of state. Nonphysical oscillations of the numerical solution near discontinuities are damped using the Kurganov‐Tadmor/Kurganov‐Noelle‐Petrova (KT/KNP) scheme for convective fluxes. The solver was validated using different test cases, where analytical and/or numerical solutions are present or can be derived: (1) A convergent‐divergent nozzle with three different operating conditions; (2) the Riemann problem for the Peng‐Robinson equation of state; (3) the Riemann problem for the covolume equation of state; (4) the development of a laminar velocity profile in a circular pipe (also known as Poiseuille flow); (5) a laminar flow over a circular cylinder; (6) a subsonic flow over a backward‐facing step at low Reynolds numbers; (7) a transonic flow over the RAE 2822 airfoil; and (8) a supersonic flow around a blunt cylinder‐flare model. The spatial approximation order of the scheme is second order. The mesh convergence of the numerical solution was achieved for all cases. The accuracy order for highly compressible flows with discontinuities is close to first order and, for incompressible viscous flows, it is close to second order. The proposed solver is named rhoPimpleCentralFoam and is implemented in the open‐source CFD library OpenFOAM®. For high speed flows, it shows a similar behavior as the KT/KNP schemes (implemented as rhoCentralFoam‐solver, Int. J. Numer. Meth. Fluids 2010), and for flows with small Mach numbers, it behaves like solvers that are based on the PISO/SIMPLE algorithm. 相似文献
407.
Binder Ilia Glucksam Adi Rojas Cristobal Yampolsky Michael 《Foundations of Computational Mathematics》2022,22(3):849-873
Foundations of Computational Mathematics - We study the question of constructive approximation of the harmonic measure $$\omega _x^\varOmega $$ of a bounded domain $$\varOmega $$ with respect to a... 相似文献
408.
The synthesis, characterization, and computational analysis of a series of low-valent, In(I) complexes bearing the bis(imino)pyridine scaffold, {Ar'N=CPh}(2)(NC(5)H(3)), is reported. A stepwise steric reduction of the aryl groups on the imine substituents around the coordination site, (Ar' = 2,5-(t)Bu(2)C(6)H(3), 2,6-(i)Pr(2)C(6)H(3), 2,6-(CH(3)CH(2))(2)C(6)H(3)) is explored through the spectroscopic and crystallographic examination of complexes [{Ar'N=CPh}(2)(NC(5)H(3))]In(+)(OTf)(-) (1-3). Compounds 1-3 displayed long In-N and In-OTf distances indicating only weak or no coordination. Application of the ligand with Ar' = 2,6-(CH(3))(2)C(6)H(3) led to an In(III) bis(imino)pyridine complex, [{2,6-Me(2)C(6)H(3)N=CPh}(2)(NC(5)H(3))]In(OTf)(2)Cl 4 with coordinated ligand, chloride, and triflate groups. Computational analysis of the interactions between the In cation and the ligands (orbital populations, bond order, and energy decomposition analysis) point to only minimal covalent interactions of the In(I) cation with the ligands. Although it features three N donor centers, the bis(imino)pyridine ligand provides little ligand-to-metal donation. A thorough electronic structure analysis revealed a correlation of compound stability with the reduced contribution of the In(I) 5s lone electron pair to the highest occupied molecular orbital (HOMO) of the cation. This effect, originating from non-bonding orbital interactions between the metal and the ligand, is more prominent in sterically crowded environments. The discovery of this correlation may help in designing new low-valent complexes. 相似文献
409.
Ilia Rodushkin Emma Engström Douglas C. Baxter 《Analytical and bioanalytical chemistry》2010,396(1):365-377
In theory, state of the art inductively coupled plasma mass spectrometry (ICP–MS) instrumentation has the prerequisite sensitivity
to carry out multi-elemental trace analyses at sub-ng L−1 to sub-pg L−1 levels in solution. In practice, constraints mainly imposed by various sources of contamination in the laboratory and the
instrument itself, and the need to dilute sample solutions prior to analysis ultimately limit detection capabilities. Here
we review these sources of contamination and, wherever possible, propose remedial strategies that we have found efficacious
for ameliorating their impact on the results of multi-elemental trace analyses by ICP–MS. We conclude by providing a list
of key points to consider when developing methods and preparing the laboratory to routinely meet the demands of multi-elemental
analyses at trace analytical levels by ICP–MS. 相似文献
410.
Ilia A. Guzei Lara C. Spencer Michael K. Ainooson James Darkwa 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(11):m336-m338
The title compound, [CoCl2(C11H20ClN2)2], forms two intramolecular hydrogen bonds [graph set S(5)] between the N atoms of the pyrazole ligands and the chloride ligands. This hydrogen‐bonding motif is uncommon among related compounds but occurs here because of the bulk of tert‐butyl substituents on the pyrazole ligands which shield the central metal atom to a significantly larger extent than pyrazole ligands with smaller 3,5‐substituents. 相似文献