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1.
Reactions occurring at surfaces and interfaces necessitate the creation of well-designed surface and interfacial structures. To achieve a combination of bulk material (i.e., framework) and void spaces, a meticulous process of “nano-architecting” of the available space is necessary. Conventional porous materials such as mesoporous silica, zeolites, and metal–organic frameworks lack advanced cooperative functionalities owing to their largely monotonous pore geometries and limited conductivities. To overcome these limitations and develop functional structures with surface-specific functions, the novel materials space-tectonics methodology has been proposed for future materials synthesis. This review summarizes recent examples of materials synthesis based on designing building blocks (i.e., tectons) and their hybridization, along with practical guidelines for implementing materials syntheses and state-of-the-art examples of practical applications. Lastly, the potential integration of materials space-tectonics with emerging technologies, such as materials informatics, is discussed.  相似文献   

2.
An analysis is presented for a simple, universal equation for the computation of attenuation lengths (L) for any material, necessary for quantifying layer thicknesses in Auger electron spectroscopy (AES) and X‐ray photoelectron spectroscopy (XPS). Attenuation lengths for selected materials may be computed from the inelastic mean free path (λOpt) computed, in turn, from optical data. The computation of L involves the transport mean free path and gives good L values where values of λOpt are available. However, λOpt values are not available for all materials. Instead, λ may be calculated from the TPP‐2M relation, but this requires the accurate estimation of a number of materials parameters that vary over a wide range. Although these procedures are all soundly based, they are impractical in many analytical situations. L is therefore simply reexpressed, here, in terms of the average Z of the layer which may be deduced from the AES or XPS analysis, the average atomic size a (varies in a small range) and the kinetic energy E of the emitted electron. For strongly bonded materials, such as oxides and alkali halides, a small extra term is included for the heat of formation. A new equation, S3, is established with a root mean square (RMS) deviation of 8% compared with the values of attenuation length calculated from λOpt available for elements, inorganic compounds, and organic compounds. This excellent result is suitable for practical analysis. In many films, an average value of a of 0.25 nm is appropriate, and then L may be expressed only in terms of the average Z and E. Then, L expressed in monolayers, equation S4, exhibits an RMS deviation of 9% for many elements. These results are valid for the energy range 100 to 30 000 eV and for angles of emission up to 65°. Copyright © 2012 Crown copyright.  相似文献   

3.
A metrological background for the selection and use of proficiency testing (PT) schemes for a limited number N of laboratories-participants (less than 20–30) is discussed. The following basic scenarios are taken into account: (1) adequate matrix certified reference materials (CRM) or in-house reference materials (IHRM) with traceable property values are available for PT use as test items; (2) no appropriate matrix CRM is available, but a CRM or IHRM with traceable property values can be applied as a spike or similar; (3) only an IHRM with limited traceability is available. The discussion also considers the effect of a limited population of PT participants N p on statistical assessment of the PT results for a given sample of N responses from this population. When N p is finite and the sample fraction N/N p is not negligible, a correction to the statistical parameters may be necessary. Scores suitable for laboratory performance assessment in such PT schemes are compared. Presented at the 3rd International Conference on Metrology, November 2006, Tel Aviv, Israel.  相似文献   

4.
An efficient method for cis-hydroxylation of vinylsilanes under very mild and practical conditions using ozone in water as well as aqueous solvents is described.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.  相似文献   

5.
No reference materials are currently available to study thermoanalytical kinetic methods, apparatus, or software. The ASTM International Committee E27 on Hazard Potential of Chemicals seeks to identify possible calorimetric reference materials for evaluating kinetic parameters, including activation energy (E), log pre-exponential factor (log Z), and reaction orders (m and n), as well as reaction enthalpy (H). Six candidate materials are examined including di-tertiary-butyl peroxide (DTBP), trityl azide, azobenzene, azobisisobutyronitrile (ABIN), cumene hydroperoxide (CHP), and phenytetrazolthiol. No single material appears to meet all needs. The merits and applicability of each candidate are discussed and recommended kinetic reference values are presented.  相似文献   

6.
Accurate determinations of stable isotope ratios require a calibration using at least two reference materials with different isotopic compositions to anchor the isotopic scale and compensate for differences in machine slope. Ideally, the δ values of these reference materials should bracket the isotopic range of samples with unknown δ values. While the practice of analyzing two isotopically distinct reference materials is common for water (VSMOW‐SLAP) and carbonates (NBS 19 and L‐SVEC), the lack of widely available organic reference materials with distinct isotopic composition has hindered the practice when analyzing organic materials by elemental analysis/isotope ratio mass spectrometry (EA‐IRMS). At present only L‐glutamic acids USGS40 and USGS41 satisfy these requirements for δ13C and δ15N, with the limitation that L‐glutamic acid is not suitable for analysis by gas chromatography (GC). We describe the development and quality testing of (i) four nicotine laboratory reference materials for on‐line (i.e. continuous flow) hydrogen reductive gas chromatography‐isotope ratio mass‐spectrometry (GC‐IRMS), (ii) five nicotines for oxidative C, N gas chromatography‐combustion‐isotope ratio mass‐spectrometry (GC‐C‐IRMS, or GC‐IRMS), and (iii) also three acetanilide and three urea reference materials for on‐line oxidative EA‐IRMS for C and N. Isotopic off‐line calibration against international stable isotope measurement standards at Indiana University adhered to the ‘principle of identical treatment’. The new reference materials cover the following isotopic ranges: δ2Hnicotine ?162 to ?45‰, δ13Cnicotine ?30.05 to +7.72‰, δ15Nnicotine ?6.03 to +33.62‰; δ15Nacetanilide +1.18 to +40.57‰; δ13Curea ?34.13 to +11.71‰, δ15Nurea +0.26 to +40.61‰ (recommended δ values refer to calibration with NBS 19, L‐SVEC, IAEA‐N‐1, and IAEA‐N‐2). Nicotines fill a gap as the first organic nitrogen stable isotope reference materials for GC‐IRMS that are available with different δ15N values. Comparative δ13C and δ15N on‐line EA‐IRMS data from 14 volunteering laboratories document the usefulness and reliability of acetanilides and ureas as EA‐IRMS reference materials. Published in 2009 by John Wiley & Sons, Ltd.  相似文献   

7.
Abstract

Utilizing phosphorus version of the Fritsch-Buttenberg-Wiechell (FBW) reaction, arylphosphaalkynes are prepared from 2,2-dihalo-1-aryl-1-phosphaalkenes, and theoretical calculations were carried out to obtain some basic insight into intramolecular rearrangement in the phosphorus system of interest.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Density functional theory (DFT) and ab initio MP2 calculations.]

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon for the following free supplemental files: Additional tables, figures, and references.]  相似文献   

8.
A facile and effective synthesis of N‐vinylpyrroles had been explored. The synthetic approach was practicable for preparation of N‐vinylpyrroles for the mild reaction conditions and readily available materials, compared with previously inaccessible N‐vinylpyrroles with electron‐withdrawing groups, especially these pyrroles bearing alkaline sensitive substitution groups.  相似文献   

9.
Sigvart Evjen 《合成通讯》2017,47(15):1392-1399
We have developed improved general simple methods for large-scale preparation of polyalkylated imidazoles by improved multicomponent synthesis from commercially available starting materials. A large range of NH- and N-alkyl-polyalkylimidazoles (40 in total, including novel compounds) has been synthesized.  相似文献   

10.
The syntheses of various types of 1,2,3-triazole-based dendrimers 14 with sugar pyranosylazides and N-ethyl and N-heptylazides as a surface unit and benzene-1,3,5-tricorboxlyic amide as core unit through click chemistry approach are described.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.  相似文献   

11.
5-Ethyl-3-methyl-2′,4′:3′,5′-di-O-methylenedioxyriboflavinium perchlorate (1, DMRFlEt+ClO4 ), derived readily from commercially available vitamin B2 (riboflavin), exhibits high catalytic activity for the oxidation of organic sulfides with hydrogen peroxide. The reaction provides an efficient and selective method for the oxidative transformation of organic sulfides to the corresponding sulfoxides under mild conditions.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]  相似文献   

12.
Circularly polarized electroluminescence (CP-EL) is generally produced in organic light-emitting diodes (OLEDs) based on special CP luminescent (CPL) materials, while common achiral luminescent materials are rarely considered to be capable of direct producing CP-EL. Herein, near ultraviolet CPL materials with high photoluminescence quantum yields and good CPL dissymmetry factors are developed, which can induce blue to red CPL for various achiral luminescent materials. Strong near ultraviolet CP-EL with the best external quantum efficiencies (ηexts) of 9.0 % and small efficiency roll-offs are achieved by using them as emitters for CP-OLEDs. By adopting them as hosts or sensitizers, commercially available yellow-orange achiral phosphorescence, thermally activated delayed fluorescence (TADF) and multi-resonance (MR) TADF materials can generate intense CP-EL, with high dissymmetry factors and outstanding ηexts (30.8 %), demonstrating a simple and universal avenue towards efficient CP-EL.  相似文献   

13.
Albert Corominas 《合成通讯》2013,43(15):2062-2072
A method to generate carbonylic compounds from alkynes under mild and neutral conditions, with excellent functional group compatibility and good yields, is described. Hydration takes place under catalytic conditions by using 0.1 to 0.2 equivalents of the easily available and inexpensive mercury(II) p-toluensulfonamidate in a hydroalcoholic solution. After use, the catalyst is rendered inert and/or recycled.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.  相似文献   

14.
A novel synthetic route has been reported for the synthesis of nonenolide. The syntheses of fragments were initiated from commercially available and inexpensive starting materials. The synthesis involves key steps like Sharpless epoxidation, Jacobsen's resolution, lactonization, and cross‐metathesis.  相似文献   

15.
Abstract

A practical metal-free procedure for the synthesis of (E)-vinyl sulfones has been developed through the coupling of β-nitrostyrenes with sodium sulfinates under microwave irradiation. This methodology provides a convenient and efficient approach to various (E)-vinyl sulfones from readily available starting materials with excellent regioselectivity. The present oxidative reaction involves an efficient denitrative radical cross-coupling of β-nitrostyrenes with sodium sulfinates via using AcOH as an additive.  相似文献   

16.
A series of N-substituted phthalimides was synthesized by a thermal reaction between N,N′-disubstituted ureas and phthalic acid catalyzed by imidazole in solventless conditions. The products have been obtained in moderate to good yields (53–92%).

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.  相似文献   

17.
A practical and convenient synthesis of the fungicidal natural compound farinomalein is described starting from readily available ethyl 3-methyl-2-oxobutyrate and triethyl phosphonoacetate, employing a Horner–Wadsworth–Emmons condensation as the key step.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.  相似文献   

18.
A synthesis of functionalized N-arylsulfonyl pyrazoles from the multicomponent reaction of arylsulfonyl hydrazones and dialkyl acetylenedicarboxylates in the presence nucleophilic compounds such as pyridine, isoquinoline, or triphenylphosphine, in good yields, is described.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resources: Full experimental and spectral details.]  相似文献   

19.
The nucleophilic substitution reaction of carbohydrate imidazole-1-sulfonates with pyrrole and other nitrogen heterocyclic compounds is reported for the first time. Several novel N-carbohydrate-derived heterocyclic compounds have been prepared by this displacement reaction. The desired carbon-nitrogen bond formation proceeds under mild conditions to generate the coupling products in good yields with readily available and inexpensive reagents. This method is particularly suitable for carbohydrate imidazole-1-sulfonates of primary alcohols. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of Carbohydrate Chemistry to view the free supplemental file.  相似文献   

20.
A convenient and facile enantioselective synthesis of (?)-erinapyrone B from commercially available D-(+)-malic acid has been achieved in seven steps. One of the key steps in this synthesis was the one-pot reaction of palladium(II)-mediated Wacker-type oxidative cyclization in the presence of a catalytic amount of p-toluenesulphonic acid (p-TsOH) which has been found to be effective for the preparation of enantiopure 2,3-dihydro-4H-pyran-4-one from the corresponding enantiopure β-hydroxyenone via enantio-enriched diketohydroxy intermediate.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]  相似文献   

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