Catalytic domino amination and oxidative coupling of gold acetylides and isolation of key vinylene digold intermediates as a new class of ditopic N-heterocyclic carbene complexes

2017 ◽  
Vol 53 (78) ◽  
pp. 10835-10838 ◽  
Author(s):  
Haifeng Chen ◽  
Jiwei Wang ◽  
Zejun Hu ◽  
Sheng Xu ◽  
Min Shi ◽  
...  
Keyword(s):  
Oxidative Coupling ◽  
Gold Complexes ◽  
Carbene Complexes ◽  
New Class

A catalytic domino amination and oxidative coupling of in situ prepared gold acetylides has been developed for the synthesis of abnormal NHC (aNHC) gold complexes, and key vinylene digold intermediates are isolated.

Mechanochemical changes on cyclometalated Ir(iii) acyclic carbene complexes – design and tuning of luminescent mechanochromic transition metal complexes

2020 ◽  
Vol 7 (3) ◽  
pp. 786-794 ◽  
Author(s):  
Jingqi Han ◽  
Kin-Man Tang ◽  
Shun-Cheung Cheng ◽  
Chi-On Ng ◽  
Yuen-Kiu Chun ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Carbene Complexes ◽  
New Class

A new class of luminescent cyclometalated Ir(iii) complexes with readily tunable mechanochromic properties derived from the mechanically induced trans-to-cis isomerization have been developed.

scholarly journals Phase Transitions in Borohydride Perovskites

2014 ◽  
Vol 70 (a1) ◽  
pp. C73-C73
Author(s):  
Pascal Schouwink ◽  
Radovan Cerny
Keyword(s):  
Phase Transitions ◽  
Volume Expansion ◽  
Host Lattice ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
New Class ◽  
Structural Distortions ◽  
Complex Hydrides ◽  
Type Lattice

A series of complex hydrides based on the highly dynamic tetrahydroborate anion BH4-and crystallizing in theABX3type lattice has recently been discovered. They present a rare case of a family of iono-covalent hydrides that has a genuine tunable host lattice, making them an interesting new class of host compounds for not only the design of hydrogen storage materials but also hydride-properties related to heavy metals. Amongst these, preliminary results onREE-based luminescence will be discussed in the neat and doped compounds, the Ln2+excited states surprisingly not being subject to significant quenching by B-H vibrations. Unlike oxide- or halide-perovskites some members of theAB(BH4)3group do not evolve to higher symmetries as a function of temperature. We show by means ofin-situsynchrotron X-ray powder diffraction, vibrational spectroscopy andab initiocalculations in the solid state, that temperature-induced structural distortions in perovskite-typeACa(BH4)3(A= K, Rb, Cs) have their origin in close hydridic di-hydrogen contacts of repulsive nature. Coupling between internal B-H vibrations and phonons results in lattice distortions that are identical in symmetry to well-known instabilities (soft modes) in perovskites, which generally condense to lower temperatures. Anion-substitution BH4-<->X-(X= Halide) calculated on ordered models can relax distortions caused by repulsive effects. High temperature phase-transitions inACa(BH4)3can be of first or second-order, including 2-fold superlattices, simple cubic-cubic transitions accompanied by volume expansion or complex modulated superstructures accompanied by negative volume expansion, as is the case in RbCa(BH4)3. Close di-hydrogen contacts may be suggested as a tool to tailor the crystal symmetry in complex hydride perovskites in the future.

In situ intercalative polymerization of pyrrole in Fe0Cl: a new class of layered, conducting polymer-inorganic hybrid materials

1987 ◽  
Vol 109 (12) ◽  
pp. 3797-3799 ◽  
Author(s):  
M. G. Kanatzidis ◽  
L. M. Tonge ◽  
T. J. Marks ◽  
H. O. Marcy ◽  
C. R. Kannewurf
Keyword(s):  
Conducting Polymer ◽  
Hybrid Materials ◽  
Inorganic Hybrid ◽  
New Class ◽  
Intercalative Polymerization

scholarly journals Twistable electronics with dynamically rotatable heterostructures

Science ◽  
2018 ◽  
Vol 361 (6403) ◽  
pp. 690-693 ◽  
Author(s):  
Rebeca Ribeiro-Palau ◽  
Changjian Zhang ◽  
Kenji Watanabe ◽  
Takashi Taniguchi ◽  
James Hone ◽  
...  
Keyword(s):  
Rotation Angle ◽  
Electronic Devices ◽  
Long Wavelength ◽  
New Class ◽  
On Demand ◽  
Device Architecture ◽  
Two Dimensional Materials ◽  
Electronic Response ◽  
Small Rotation

In heterostructures of two-dimensional materials, electronic properties can vary dramatically with relative interlayer angle. This effect makes it theoretically possible to realize a new class of twistable electronics in which properties can be manipulated on demand by means of rotation. We demonstrate a device architecture in which a layered heterostructure can be dynamically twisted in situ. We study graphene encapsulated by boron nitride, where, at small rotation angles, the device characteristics are dominated by coupling to a long-wavelength moiré superlattice. The ability to investigate arbitrary rotation angle in a single device reveals features of the optical, mechanical, and electronic response in this system not captured in static rotation studies. Our results establish the capability to fabricate twistable electronic devices with dynamically tunable properties.

The aryl iodine-catalyzed organic transformation via hypervalent iodine species generated in situ

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xuemin Li ◽  
Guangchen Li ◽  
Yifu Cheng ◽  
Yunfei Du
Keyword(s):  
Organic Synthesis ◽  
Oxidative Coupling ◽  
Hypervalent Iodine ◽  
Organic Transformations ◽  
Aryl Iodide ◽  
Oxidative Reaction ◽  
Iodine Species ◽  
Iodine Chemistry

Abstract The application of hypervalent iodine species generated in situ in organic transformations has emerged as a useful and powerful tool in organic synthesis, allowing for the construction of a series of bond formats via oxidative coupling. Among these transformations, the catalytic aryl iodide can be oxidized to hypervalent iodine species, which then undergoes oxidative reaction with the substrates and the aryl iodine regenerated again once the first cyclic cycle of the reaction is completed. This review aims to systematically summarize and discuss the main progress in the application of in situ-generated hypervalent iodine species, providing references and highlights for synthetic chemists who might be interested in this field of hypervalent iodine chemistry.

In-Situ Oxidative Degradation of Emerging Contaminants in Soil and Groundwater Using a New Class of Stabilized MnO2 Nanoparticles

2016 ◽  
pp. 112-136
Author(s):  
Bing Han ◽  
Wen Liu ◽  
Dongye Zhao
Keyword(s):  
Organic Contaminants ◽  
Emerging Contaminants ◽  
Low Cost ◽  
Oxidative Degradation ◽  
In Situ Remediation ◽  
New Class ◽  
Mno2 Nanoparticles ◽  
In Situ Degradation ◽  
Trace Concentrations

Emerging Organic Contaminants (EOCs) such as steroidal estrogen hormones are of growing concern in recent years, as trace concentrations of these hormones can cause adverse effects on the environmental and human health. While these hormones have been widely detected in soil and groundwater, effective technology has been lacking for in-situ degradation of these contaminants. This chapter illustrates a new class of stabilized MnO2 nanoparticles and a new in-situ technology for oxidative degradation of EOCs in soil and groundwater. The stabilized nanoparticles were prepared using a low-cost, food-grade Carboxymethyl Cellulose (CMC) as a stabilizer. The nanoparticles were then characterized and tested for their effectiveness for degradation of both aqueous and soil-sorbed E2 (17ß-estradiol). Column tests confirmed the effectiveness of the nanoparticles for in-situ remediation of soil sorbed E2. The nanoparticle treatment decreased both water leachable and soil-sorbed E2, offering a useful alternative for in-situ remediation of EOCs in the subsurface.

scholarly journals In situ X-ray diffraction computed tomography studies examining the thermal and chemical stabilities of working Ba0.5Sr0.5Co0.8Fe0.2O3−δ membranes during oxidative coupling of methane

2020 ◽  
Vol 22 (34) ◽  
pp. 18964-18975
Author(s):  
Dorota Matras ◽  
Antonis Vamvakeros ◽  
Simon D. M. Jacques ◽  
Vesna Middelkoop ◽  
Gavin Vaughan ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Solid State ◽  
Oxidative Coupling ◽  
Structural Changes ◽  
Oxidative Coupling Of Methane ◽  
Membrane Reactors ◽  
Solid State Chemistry ◽  
X Ray Diffraction ◽  
X Ray

In situ XRD-CT and post-reaction SEM/EDX were used to study the solid-state chemistry and structural changes of Ba0.5Sr0.5Co0.8Fe0.2O3−δ membrane reactors during the oxidative coupling of methane reaction.

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