In situ ortho-lithiation/functionalization of pentafluorosulfanyl arenes

2022 ◽  
Author(s):  
Thanh V. Le ◽  
Olafs Daugulis
Keyword(s):  
General Method

A general method for ortho-functionalization of pentafluorosulfanyl arenes has been developed.

Reductive Cleavage of Secondary Sulfonamides: Converting Terminal Functional Groups into Versatile Synthetic Handles

2019 ◽  
Author(s):  
Patrick Fier ◽  
Suhong Kim ◽  
Kevin M. Maloney
Keyword(s):  
Functional Groups ◽  
Late Stage ◽  
Reductive Cleavage ◽  
Bioactive Molecules ◽  
General Method

Sulfonamides are pervasive in drugs and agrochemicals, yet are typically considered as terminal functional groups rather than synthetic handles. To enable the general late-stage functionalization of secondary sulfonamides, we have developed a mild and general method to reductively cleave the N-S bonds of sulfonamides to generate sulfinates and amines, components which can further react <i>in-situ</i> to access a variety of other medicinally relevant functional groups. The utility of this platform is highlighted by the selective manipulation of several complex bioactive molecules.

scholarly journals Facile Synthesis of Pd@PtM (M = Rh, Ni, Pd, Cu) Multimetallic Nanorings as Efficient Catalysts for Ethanol Oxidation Reaction

2021 ◽  
Vol 9 ◽  
Author(s):  
Xingqiao Wu ◽  
Xiao Li ◽  
Yucong Yan ◽  
Sai Luo ◽  
Jingbo Huang ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Epitaxial Growth ◽  
Oxidation Reaction ◽  
Ethanol Oxidation ◽  
Hollow Structure ◽  
Ethanol Oxidation Reaction ◽  
Hollow Nanostructures ◽  
Oxidative Etching ◽  
General Method

Pt-based multimetallic nanorings with a hollow structure are attractive as advanced catalysts due to their fantastic structure feature. However, the general method for the synthesis of such unique nanostructures is still lack. Here we report the synthesis of Pd@PtM (M = Rh, Ni, Pd, Cu) multimetallic nanorings by selective epitaxial growth of Pt alloyed shells on the periphery of Pd nanoplates in combination with oxidative etching of partial Pd in the interior. In situ generation of CO and benzoic acid arising from interfacial catalytic reactions between Pd nanoplates and benzaldehyde are critical to achieve high-quality Pt-based multimetallic nanorings. Specifically, the in-situ generated CO promotes the formation of Pt alloyed shells and their epitaxial growth on Pd nanoplates. In addition, the as-formed benzoic acid and residual oxygen are responsible for selective oxidative etching of partial Pd in the interior. When evaluated as electrocatalysts, the Pd@PtRh nanorings exhibit remarkably enhanced activity and stability for ethanol oxidation reaction (EOR) compared to the Pd@PtRh nanoplates and commercial Pt/C due to their hollow nanostructures.

scholarly journals Core–shell zeolite@aqueous miscible organic-layered double hydroxides

2016 ◽  
Vol 7 (2) ◽  
pp. 1457-1461 ◽  
Author(s):  
Chunping Chen ◽  
Coral F. H. Byles ◽  
Jean-Charles Buffet ◽  
Nicholas H. Rees ◽  
Yue Wu ◽  
...  
Keyword(s):  
Layered Double Hydroxide ◽  
Hybrid Materials ◽  
Layered Double Hydroxides ◽  
Coprecipitation Method ◽  
Core Shell ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Microporous Zeolite ◽  
General Method

We report a general method for the synthesis of core–shell hybrid materials containing a microporous zeolite core with an aqueous miscible organic-layered double hydroxide (AMO-LDH) shell using a simplein situcoprecipitation method.

scholarly journals A General Method for Estimating Bulk 2D Projections of Ice Particle Shape: Theory and Applications

2019 ◽  
Vol 76 (1) ◽  
pp. 305-332 ◽  
Author(s):  
Edwin L. Dunnavan ◽  
Zhiyuan Jiang
Keyword(s):  
Aspect Ratio ◽  
Particle Shape ◽  
Ratio Distribution ◽  
Aspect Ratios ◽  
Shape Uncertainty ◽  
Aspect Ratio Distribution ◽  
Spheroidal Geometry ◽  
Orientation Parameters ◽  
General Method

Abstract The orientation of falling ice particles directly influences estimates of microphysical and radiative bulk quantities as well as in situ retrievals of size, shape, and mass. However, retrieval efforts and bulk calculations often incorporate very basic orientations or ignore these effects altogether. To address this deficiency, this study develops a general method for projecting bulk distributions of particle shape for arbitrary orientations. The Amoroso distribution provides the most general bulk aspect ratio distribution for gamma-distributed particle axis lengths. The parameters that govern the behavior of this aspect ratio distribution depend on the assumed relationship between mass, maximum dimension, and aspect ratio. Individual spheroidal geometry allows for eccentricity quantities to linearly map onto ellipse analogs, whereas aspect ratio quantities map nonlinearly. For particles viewed from their side, this analytic distinction leads to substantially larger errors in projected aspect ratio than for projected eccentricity. Distribution transformations using these mapping equations and numerical integration of projection kernels show that both truncation of size distributions and changes in Gaussian dispersion can alter the modality and shape of projection distributions. As a result, the projection process can more than triple the relative entropy between the spheroidal and projection distributions for commonly assumed model and orientation parameters. This shape uncertainty is maximized for distributions of highly eccentric particles and for particles like aggregates that are thought to fall with large canting-angle deviations. As a result, the methods used to report projected aspect ratios and the corresponding values should be questioned.

Application of modulation excitation-phase sensitive detection-DRIFTS for in situ/operando characterization of heterogeneous catalysts

2019 ◽  
Vol 4 (5) ◽  
pp. 862-883 ◽  
Author(s):  
Priya D. Srinivasan ◽  
Bhagyesha S. Patil ◽  
Hongda Zhu ◽  
Juan J. Bravo-Suárez
Keyword(s):  
Fourier Transform ◽  
Heterogeneous Catalysts ◽  
Diffuse Reflectance ◽  
Sensitive Detection ◽  
Phase Sensitive ◽  
Phase Sensitive Detection ◽  
Modulation Excitation ◽  
General Method

A new more general method and guidelines for the implementation of modulation excitation-phase sensitive detection-diffuse reflectance Fourier transform spectroscopy (ME-PSD-DRIFTS).

Origin of the ϕ ∼ ±9° peaks in YBa2Cu3O7−δ films grown on cubic zirconia substrates

1996 ◽  
Vol 11 (6) ◽  
pp. 1336-1348 ◽  
Author(s):  
D. G. Schlom ◽  
E. S. Hellman ◽  
E.H. Hartford ◽  
C.B. Eom ◽  
J. C. Clark ◽  
...  
Keyword(s):  
Reaction Layer ◽  
Growth Conditions ◽  
Ex Situ ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
Lattice Match ◽  
Cubic Zirconia ◽  
General Method

The c-axis oriented YBa2Cu3O7−δ films grown on (001) yttria-stabilized cubic zirconia (YSZ) substrates often contain domains whose in-plane alignment is rotated approximately 9° from the cube-on-cube epitaxial relationship, in addition to the more commonly observed 0° and 45° in-plane rotations. We have investigated the origin of this ∼9° orientation using in situ electron diffraction during growth and ex situ 4-circle x-ray diffraction. Our results indicate that the ∼9° orientation provides the most favorable lattice match between the interfacial (110)-oriented BaZrO3 epitaxial reaction layer, which forms between YBa2Cu3O7−δ and the YSZ substrate. If epitaxy occurs directly between YBa2Cu3O7−δ and the YSZ substrate, i.e., before the BaZrO3 epitaxial reaction layer is formed, the 0° and 45° domains have the most favorable lattice match. However, growth conditions that favor the formation of the BaZrO3 reaction layer prior to the nucleation of YBa2Cu3O7−δ lead to an increase in ∼9° domains. The observed phenomenon, which results from epitaxial alignment between the diagonal of a square surface net and the diagonal of a rectangular surface net, is a general method for producing in-plane misorientations, and has also been observed for the heteroepitaxial growth of other materials, including (Ba, K)BiO3/LaAlO3. The YBa2Cu3O7−δ/YSZ case involves epitaxial alignment between [111]BaZrO3 and [110]YSZ, resulting in an expected in-plane rotation of 11.3° to 9.7° for fully commensurate and for fully relaxed (110)BaZrO3 on (001)YSZ, respectively.

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