Reduction of Diaryldiselenides by System of Cp_2TiCl_2/Bu^iMgBr/THF and Its Application in Synthesis of Unsymmetrical Diaryl Selenides

Reduction of diaryldiselenides by the system of Cp2TiCl2/Bu'MgBr/THF gave the nucleophilic arylselenium complex. They reacted with diaryl iodonium salts to afford unsymmetrical diaryl selenides in high yields.

Stereoselective Synthesis of δd-Selanyl Allylic Alcohols by Hydrozirconation of Propargyl Selenides

Hydrozirconation of propargyl selenides afford (E)-3-selanyl vinylzirconocenes chlorides 2. Intermediates 2 reacted with aldehydes to obtain d-selanyl allylic alcohols.

Two-in-one shell configuration for bimetal selenides toward fast sodium storage within broadened voltage windows

The shell structure design has been recognized as a highly efficient strategy to buffer the severe volume expansion and consecutive pulverization of conversion-type anodes.Nevertheless,construction of a functional shell with a stabilized structure that meets the demands of both high electronic conductivity and feasible pathways for Na^(+)ions has been a challenge so far.Herein,we design a two-in-one shell configuration for bimetal selenides to achieve fast sodium storage within broadened voltage windows.The hybridized shell,which benefits from the combination of titanium dioxide quantum dots and amorphous carbon,can not only effectively buffer the strain and maintain structural integrity but also allow facile and reversible transport of electrons and Na^(+)uptake for electrode materials during sodiation/desodiation processes,resulting in increased reaction kinetics and diffusion of sodium ions,conferring many benefits to the functionality of conversion-type electrode materials.As a representative material,Ni-CoSe_(2) with such structural engineering shows a reversible capacity of 515 mAh g^(−1)at 0.1 A g^(−1)and a stable capacity of 416 mAh g^(−1)even at 6.4 A g^(−1);more than 80%of the capacity at 0.1 A g^(−1)could be preserved,so that this strategy holds great promise for designing fast-charging conversion-type anodes in the future.

Bismuth Mediated Organic Reaction: A Convenient Method for the Synthesis of Allylic (Benzylic) Selenides and α-Organylselenocarbonyl Compounds in Aqueous Media

In the presence of BiCl3/Al or BiCl3/Fe, in THF-H2O, allylic (benzylic) bromides or α-bromoketones react with diorganyl diselenides to give allylic (benzylic) selenides orα-organylselenocarbonyl compounds respectively in moderate to good yields.

A Novel Stereoseletive Approach to (E)-Vinylic Selenides

The insertion of elemental selenium into the Csp(2)-Zr bond of alkenylchloro-zirconocenes affords (E)-vinylseleno zirconocenes, which were trapped by alkyl halides giving (E)-vinylic selenides in moderate to good yields.

Novel Synthesis of Benzotriazol-1-yl Methyl Selenides and Tellurides

Benzotriazol-1-yl methyl selenides and tellurides 4a-h can be simply synthesized by the reaction of 2a-b with 3 in good yields.

A Superaerophobic Bimetallic Selenides Heterostructure for Efficient Industrial-Level Oxygen Evolution at Ultra-High Current Densities

Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction(OER)are critical to the energy crisis and environmental pollution.Herein,we report a superaerophobic three dimensional(3D)heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy(NiSe2/NiFe2Se4@NiFe)prepared by a thermal selenization procedure.In this unique 3D heterostructure,numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~100 nm are grown on NiFe alloy in a uniform manner.Profiting by the large active surface area and high electronic conductivity,the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media,outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm^−2,respectively,which is among the most active Ni/Fe-based selenides,and even superior to the benchmark Ir/C catalyst.The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.

A one-pot stereoselective synthesis of 1,4-dienyl selenides by hydrostannylation-Stille tandem reaction of acetylenic selenides with Bu_3SnH and allylic bromides

1,4-Dienyl selenides can be stereoselectively synthesized in one pot under mild conditions in good yields by the palladiumcatalyzed hydrostannylation of acetylenic selenides, followed by Stille coupling with allylic bromides.

High-entropy selenides: A new platform for highly selective oxidation of glycerol to formate and energy-saving hydrogen evolution in alkali-acid hybrid electrolytic cell

Glycerol oxidation reaction(GOR)coupled with hydrogen generation simultaneously is a promising strategy for developing sustainable energy conversion technologies,but the complexity of glycerol oxidation products and the high coupling hydrogen evolution potential limit its wide application.In this paper,a self-supported high-entropy selenide electrode can be fabricated via a simple hydrothermal process.Then,the prepared electrode as an advanced catalyst displays optimal catalytic activity(1.20 V at 10 mA·cm^(−2))and high selectivity for the formation of formate in GOR.The results show that the lattice distortion effect of high entropy materials composed of multiple elements is mainly responsible for the greatly improved catalytic activity and selectivity for GOR.Moreover,an advanced alkali-acid hybrid electrolytic cell was assembled that enables efficient energy-saving hydrogen generation and GOR simultaneously.Herein,the electrolyzer requires only 0.5 V applied voltage to reach 10 mA·cm^(−2) for hydrogen generation and maintains long-term operation stability.

Low-cost and environmentally benign selenides as promising thermoelectric materials

Developing high-efficiency materials with earth-abundant and low-toxicity elements has become a popular trend in the field of thermoelectrics.Among these compounds,oxides and sulfides,the lighter,cheaper and green analogies of tellurides,have been extensively investigated and summarized as well defined classes.Nonetheless,the vast family of selenides with better electrical performance,lower thermal conductivity and higher thermoelectric efficiency have not been specially discussed.Here in this review,we present recent advances in binary and multinary selenide thermoelectric materials,covering traditional PbSe,liquid-like Cu_(2)Se,layered SnSe,diamond-like and disordered multinary compounds.The features of selenides are discussed based on both environmental concerns and from the perspective of chemical bonding,transport properties and performance.Emphasis is put on the“compositionstructure-processing-performance”relationship,and some interesting issues are addressed.Finally,challenges for thermoelectric selenides are discussed,and possible optimization strategies are also suggested.

Phase boundary engineering of metal-organic-framework-derived carbonaceous nickel selenides for sodium-ion batteries

Nano Research volume 13,pages2289–2298(2020)Cite this article 347 Accesses 1 Altmetric Metrics details Abstract Sodium-ion batteries(SIBs)are promising power sources due to the low cost and abundance of battery-grade sodium resources,while practical SIBs suffer from intrinsically sluggish diffusion kinetics and severe volume changes of electrode materials.Metal-organic framework(MOFs)derived carbonaceous metal compound offer promising applications in electrode materials due to their tailorable composition,nanostructure,chemical and physical properties.Here,we fabricated hierarchical MOF-derived carbonaceous nickel selenides with bi-phase composition for enhanced sodium storage capability.As MOF formation time increases,the pyrolyzed and selenized products gradually transform from a single-phase Ni3Se4 into bi-phase NiSex then single-phase NiSe2,with concomitant morphological evolution from solid spheres into hierarchical urchin-like yolk-shell structures.As SIBs anodes,bi-phase NiSex@C/CNT-10h(10 h of hydrothermal synthesis time)exhibits a high specific capacity of 387.1 mAh/g at 0.1 A/g,long cycling stability of 306.3 mAh/g at a moderately high current density of 1 A/g after 2,000 cycles.Computational simulation further proves the lattice mismatch at the phase boundary facilitates more interstitial space for sodium storage.Our understanding of the phase boundary engineering of transformed MOFs and their morphological evolution is conducive to fabricate novel composites/hybrids for applications in batteries,catalysis,sensors,and environmental remediation.

A novel synthesis of allyl and benzyl selenides via Sm/SbCl_3 system in aqueous media

Allyl and benzyl selenides were synthesized via reactions of allyl and benzyl bromides and diselenides promoted by Sm/Sb-Cl3 system in aqueous media in moderate to good yields.

Rational design of heterostructured core-shell Co-Zn bimetallic selenides for improved sodium-ion storage

Bimetallic selenide with core-shell structure(CoSe_(2)/ZnSe/NC@ZnSe/NC)has been successfully prepared through facile carbonization and selenization processes of its core-shell metal-organic framework precursors,in which the precursor is synthesized by epitaxial growth of zinc-based zeolite imidazolate framework(ZIF-8)on the surface of cobalt-based and zinc-based zeolite imidazolate framework(ZIF-67@ZIF-8).The coreshell structure has the advantage of alleviating the volume expansion during repeated insertion and extraction of sodium ions which can effectively avoid structural collapse.Additionally,bimetallic selenides and heterostructure are effective strategies to greatly improve the rate capability of the material.Therefore,the core-shell structural CoSe2/ZnSe/NC@ZnSe/NC material can maintain the original dodecahedron structure and delivers a specific capacity of 308.6 mAh·g^(-1)at 1.0 A·g^(-1)after 300 cycles with the desirable capacity retention of 90%.With the synergistic effects of heterostructure and core-shell structure,CoSe_(2)/ZnSe/NC@ZnSe/NC exhibits better electrochemical performance than CoSe_(2)/ZnSe/NC and CoSe_(2)/NC.These prove that both core-shell structure and heterostructure have positive effects on improving the electrochemical properties of materials.

Cesium hydroxide-catalyzed hydrothiolation of alkynyl selenides to highly stereo- and regioselectively synthesize(Z)-1-organoseleno-2-arylthio-1-alkenes

In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive（Z）-1-organoseleno-2-arylthio-1-alkene in excellent yields.It could provide a new and expedient way for the preparation of（Z）-1-arylseleno-2-arylthio-1-alkene.

Chiral Cobalt(Ⅱ)Complex Catalyzed Asymmetric[2,3]-Sigmatropic Rearrangement of Allylic Selenides withα-Diazo Pyrazoleamides

Organoselenium compounds,due to their high structural diversity,special function,and biological activities,have drawn attention in synthetic chemistry.Herein,a novel example of chiral N,N′-dioxide/cobalt(Ⅱ)complex catalyzed asymmetric[2,3]-sigmatropic rearrangement of allylic selenides withα-diazo pyrazoleamides is disclosed,which represents a highly efficient approach to optically active selenides bearing a quaternary C–Se stereocenter.Most of the reactions proceed with 0.5–2 mol%catalyst loading in an inert-free gas atmosphere,and a wealth of chiral selenides are obtained in up to 99% yield and 97%enantiomeric excess(ee).The control experiments demonstrate the high reactivity of allylic selenides,as well as the conspicuous superiority of chiral N,N′-dioxide ligand andα-diazo pyrazoleamide in[2,3]-sigmatropic rearrangement.The mechanism studies reveal that the key to asymmetric rearrangement of allylic selenium ylides is the transfer of chirality from the stable chiral selenium to the carbon of the product.A feasible catalytic cycle is proposed as well.