The electroactive materials used in the counter electrode(CE)are of great concern as they influence the photovoltaic performances of dye-sensitized solar cells.The main functions of CE materials are collecting electro...The electroactive materials used in the counter electrode(CE)are of great concern as they influence the photovoltaic performances of dye-sensitized solar cells.The main functions of CE materials are collecting electrons from the external circuit and transferring them to the electrolyte and realizing the catalytic reduction of the redox species(I3^– or Co^3+)present in the electrolyte.The research hotspot of CE materials is seeking functional materials that display high efficiency,low cost,and good electrochemical stability and can substitute the benchmark platinum electrode.Chalcogen compounds of cobalt,nickel,and iron have been widely applied as CE materials and exhibit excellent electrocatalytic performances owing to their unique electrical properties,similar energies of adsorption of I atoms as platinum,excellent catalytic activities,and good chemical stabilities.In this review,we trace the developments and performances of chalcogen compounds of iron,cobalt,and nickel as CE materials and present the latest research directions for improving the electrocatalytic performances.We then highlight the optimization strategies for further improving their performances,such as fabrication of architectures,regulation of the components,synthesis of composites containing carbon materials,and elemental doping.展开更多
Gas phase carbonylation of methane is studied in the presence of molecular oxygen over pure carbon carriers and carbon supported rhodium chalcogen halides. Activated carbons and fullerene blacks have been used as carb...Gas phase carbonylation of methane is studied in the presence of molecular oxygen over pure carbon carriers and carbon supported rhodium chalcogen halides. Activated carbons and fullerene blacks have been used as carbon supports. XPS and IR-spectroscopy data show the formation of rhodium chalcogen halides in solids prepared by different methods. We have found that the productivity of acetic acid by carbon supported rhodium chalcogen halides depends strongly on the carbon carrier and the method of the catalyst preparation. Namely, the catalyst with highest productivity for the acetic acid is prepared by synthesizing the rhodium chalcogen halide over the carbon support followed by thermal destruction. We have also found that rhodium chalcogen halides over activated carbons are more active compared with fullerene supported catalysts.展开更多
We have reported a first principles study of structural, mechanical, electronic, and thermoelectric properties of the monoclinic ternary thallium chalcogenes Tl2MQ3(M = Zr, Hf;Q = S, Se, Te). The electronic band struc...We have reported a first principles study of structural, mechanical, electronic, and thermoelectric properties of the monoclinic ternary thallium chalcogenes Tl2MQ3(M = Zr, Hf;Q = S, Se, Te). The electronic band structure calculations confirm that all compounds exhibit semiconductor character. Especially, Tl2ZrTe3 and Tl2HfTe3 can be good candidates for thermoelectric materials, having narrow band gaps of 0.169 eV and 0.21 eV, respectively. All of the compounds are soft and brittle according to the second-order elastic constant calculations. Low Debye temperatures also support the softness. We have obtained the transport properties of the compounds by using rigid band and constant relaxation time approximations in the context of Boltzmann transport theory. The results show that the compounds could be considered for room temperature thermoelectric applications(ZT ~ 0.9).展开更多
The gas phase methane oxidative carbonylation was studied in the presence of molecular oxygen over silica materials including their mechanical mixtures with rhodium chalcogen chlorides obtained in non-aqueous inorgani...The gas phase methane oxidative carbonylation was studied in the presence of molecular oxygen over silica materials including their mechanical mixtures with rhodium chalcogen chlorides obtained in non-aqueous inorganic media. The formation of Rh4SCl7, Rh4S9Cl2, Rh4SesCl3 and Rh3Se3Cl solids was confirmed by elemental analysis, IR absorption spectroscopy, XPS and X-ray diffraction. Silica, vanadium-, and molybdenum-containing mesoporous molecular sieves have been used as supports. It was found that productivity of oxygenates （methanol, methyl acetate and acetic acid） depends mainly on the method of the catalyst preparation and the type of the support.展开更多
Artificial membrane transporters that either use chalcogen bonds to facilitate transmembrane flux of anions or show high selectivity toward perchlorate anions are rare.In this work,we report on one such novel monopept...Artificial membrane transporters that either use chalcogen bonds to facilitate transmembrane flux of anions or show high selectivity toward perchlorate anions are rare.In this work,we report on one such novel monopeptide-based transporter system,featuring both chalcogen bonds for highly efficient anion transport and high transport selectivity toward ClO_(4)^(-) anions.Structurally,these monopeptide molecules associate with each other via H-bonds to produce H-bonded 1D stack that not only one dimensionally but also directionally aligns the terminal bicyclic thiophene motifs to the same side.Functionally,these well-aligned thiophenes create a sulfur-rich transmembrane pathway,combinatorially fine-tunable to enable anions to efficiently cross the membrane in the increasing activity of Cl^(-)<Br^(-)<NO_(3)^(-)<ClO_(4)^(-) via chalcogen bonds,with EC_(50)values of 0.75,0.40,0.37 and 0.093μmol/L(0.3 mol%relative to lipid molecules),respectively.展开更多
Increasing risks of incidental and occupational exposures to two-dimensional transition metal dichalcogenides(2D TMDCs)due to their broad application in various areas raised their public health concerns.While the comp...Increasing risks of incidental and occupational exposures to two-dimensional transition metal dichalcogenides(2D TMDCs)due to their broad application in various areas raised their public health concerns.While the composition-dependent cytotoxicity of 2D TMDCs has been well-recognized,how the outer chalcogenide atoms and inner transition metal atoms differentially contribute to their perturbation on cell homeostasis at non-lethal doses remains to be identified.In the present work,we compared the autophagy induction and related mechanisms in response to WS_(2),NbS_(2),WSe_(2)and Nb Se_(2)nanosheets exposures in MH-S murine alveolar macrophages.All these 2D TMDCs had comparable physicochemical properties,overall cytotoxicity and capability in triggering autophagy in MH-S cells,but showed outer chalcogen-dependent subcellular localization and activation of autophagy pathways.Specifically,WS_(2)and NbS_(2)nanosheets adhered on the cell surface and internalized in the lysosomes,and triggered m TOR-dependent activation of autophagy.Meanwhile,WSe_(2)and Nb Se_(2)nanosheets had extensive distribution in cytoplasm of MH-S cells and induced autophagy in an m TOR-independent manner.Furthermore,the 2D TMDCs-induced perturbation on autophagy aggravated the cytotoxicity of respirable benzo[a]pyrene.These findings provide a deeper insight into the potential health risk of environmental 2D TMDCs from the perspective of homeostasis perturbation.展开更多
This paper presents a versatile method for synthesizing electron-rich polynuclear transition metal clusters with chalcogen bridges and phosphine ligands.The reactions of transition metal complexes(R3P)2MX2(M=Co,Ni;R=P...This paper presents a versatile method for synthesizing electron-rich polynuclear transition metal clusters with chalcogen bridges and phosphine ligands.The reactions of transition metal complexes(R3P)2MX2(M=Co,Ni;R=Ph,Bu,Et;X=Cl,Br) with bridging reagents Na2Ex (E=S,Se;x=1.2) are described.The geometric and electronic structures of a series of polynuclear transition metal clusters with trianglar M3 units are also discussed.展开更多
The in-situ generated oxyanions at electrochemically reconstructed catalysts from metal-based nonoxide compounds have been proven to significantly accelerate oxygen evolution reaction(OER)kinetics.However,it remains a...The in-situ generated oxyanions at electrochemically reconstructed catalysts from metal-based nonoxide compounds have been proven to significantly accelerate oxygen evolution reaction(OER)kinetics.However,it remains a challenge to retain these self-released oxyanions at reconstructed catalysts,hindering its utilization as a tool to develop efficient OER catalysts.Here,we demonstrate a versatile selftransformed carbonate regulation strategy to efficiently retain the self-released chalcogenate at Co oxyhydroxides reconstructed from carbon-incorporated Co selenides under OER conditions.These selftransformed CO_(3)^(2-)can induce electron accumulation and narrow d bond at Co sites to facilitate the Co3d-O 2p orbital hybridization between Co sites and SeO_(x)^(2-)for enhanced SeO_(x)^(2-)retention,which can accelerate the rate-limiting step for^(*)OOH formation during OER.Relative to CoOOH-SeO_(x)^(2-)with limited SeO_(x)^(2-)residues,CoOOH-CO_(3)^(2-)/SeO_(x)^(2-)with elevated SeO_(x)^(2-)retention by CO_(3)^(2-)regulation exhibited a 5.6-fold increase in current density and a remarkable lower Tafel slope towards OER.This strategy paves a rational avenue to design efficient catalysts for electrooxidation reactions through finely regulating self-released oxyanions at reconstructed structures.展开更多
The electronic configuration of central metal atoms in single-atom catalysts(SACs)is pivotal in electrochemical CO_(2) reduction reaction(eCO_(2)RR).Herein,chalcogen heteroatoms(e.g.,S,Se,and Te)were incorporated into...The electronic configuration of central metal atoms in single-atom catalysts(SACs)is pivotal in electrochemical CO_(2) reduction reaction(eCO_(2)RR).Herein,chalcogen heteroatoms(e.g.,S,Se,and Te)were incorporated into the symmetric nickel-nitrogen-carbon(Ni-N_(4)-C)configuration to obtain Ni-X-N_(3)-C(X:S,Se,and Te)SACs with asymmetric coordination presented for central Ni atoms.Among these obtained Ni-X-N_(3)-C(X:S,Se,and Te)SACs,Ni-Se-N_(3)-C exhibited superior eCO_(2)RR activity,with CO selectivity reaching~98% at-0.70 V versus reversible hydrogen electrode(RHE).The Zn-CO_(2) battery integrated with Ni-Se-N_(3)-C as cathode and Zn foil as anode achieved a peak power density of 1.82 mW cm^(-2) and maintained remarkable rechargeable stability over 20 h.In-situ spectral investigations and theoretical calculations demonstrated that the chalcogen heteroatoms doped into the Ni-N_(4)-C configuration would break coordination symmetry and trigger charge redistribution,and then regulate the intermediate behaviors and thermodynamic reaction pathways for eCO_(2)RR.Especially,for Ni-Se-N_(3)-C,the introduced Se atoms could significantly raise the d-band center of central Ni atoms and thus remarkably lower the energy barrier for the rate-determining step of ^(*)COOH formation,contributing to the promising eCO_(2)RR performance for high selectivity CO production by competing with hydrogen evolution reaction.展开更多
Growing interest in non-covalent interactions involving chalcogen atoms has been ascribed to their importance in crystal engineering, molecular recognition and macromolecular edifices. The present study is dealing wit...Growing interest in non-covalent interactions involving chalcogen atoms has been ascribed to their importance in crystal engineering, molecular recognition and macromolecular edifices. The present study is dealing with chalcogen bonds involving divalent Sulphur, Selenium and Tellurium atoms, acting as sigma-hole donors, in small-molecule compounds using the Cambridge Structural Database (CSD) in conjunction with ab initio calculations. Results derived from CSD surveys and computational study revealed that nucleophiles formed complexes with the chalcogen-bond donors R1-X-R2 (X = S, Se or Te). The main forces stabilizing the complexes were chalcogen bonds, enhanced by dispersion interactions. Complexation pattern and energetics show that nucleophile bonding at divalent S, Se and Te atoms is a relatively strong and directed interaction. The bond consists of a charge transfer from a nucleophile atom lone pair to an X-R1 or X-R2 antibonding orbital.展开更多
Upon irradiation by blue LED(λ>460 nm),the tricyano osmium nitrido complex[Os^(VI)(N)(L)(CN)_(3)]^(-)(OsN)in its excited state readily abstracts chalcogen atoms from the anions NCE^(-)(E=O,S,Se)to give the corresp...Upon irradiation by blue LED(λ>460 nm),the tricyano osmium nitrido complex[Os^(VI)(N)(L)(CN)_(3)]^(-)(OsN)in its excited state readily abstracts chalcogen atoms from the anions NCE^(-)(E=O,S,Se)to give the corresponding metal chalcogenonitrosyls[Os^(Ⅱ)(NuE)(L)(CN)_(3)]^(-)(OsNE)and CN^(-).A similar S atom abstraction also occurs in the photoreaction of OsN with organic sulfide,such as diisopropyl sulfide.展开更多
The solid-state structures of co-crystals of chalcogenadiazoles(ChDAs)with planar half-lantern Pt_(2)^(Ⅱ) and mononuclear Pt^(Ⅱ)complexes exhibit short Ch…Pt^(Ⅱ)(Ch=Se,Te)contacts that occur between a metal site a...The solid-state structures of co-crystals of chalcogenadiazoles(ChDAs)with planar half-lantern Pt_(2)^(Ⅱ) and mononuclear Pt^(Ⅱ)complexes exhibit short Ch…Pt^(Ⅱ)(Ch=Se,Te)contacts that occur between a metal site and the ChDA.The structures demonstrate a unique geometric feature whereby the two deepσ-holes of ChDA are turned away from a d_(z^(2))-nucleophilic PtII site.展开更多
The interactions of tripleσ-(Q^(IV))-hole donating chalconium cations([Q(bPh)R]^(+),when Q=S,Se,and Te)with nucleophilic beta-octamolybdate([β-Mo_(8)O_(26)]^(4-))result in supramolecular association.The main focus o...The interactions of tripleσ-(Q^(IV))-hole donating chalconium cations([Q(bPh)R]^(+),when Q=S,Se,and Te)with nucleophilic beta-octamolybdate([β-Mo_(8)O_(26)]^(4-))result in supramolecular association.The main focus of such assembly is onσ-(Q^(IV))-hole recognition by the molybdate in cations with a biphenyl aromatic fragment.This leads to a remarkable diversity of the association patterns producing:(i)neutral 4:1{[Q(bPh)R]^(4)[β-Mo_(8)O_(26)]}complexes with cations stacked byπ-πinteractions;(ii)(Bu_(4)N)^(+),[Q(bPh)R]^(+)and[β-Mo_(8)O_(26)]^(4-)complexes of 2:2:1 stoichiometry withπ-πinteractions;(iii)(Bu4N)+,[Q(bPh)R]+and[β-Mo_(8)O_(26)]^(4-)complexes of a 2:2:1 stoichiometry withoutπ-πinteractions;and(iv){[Q(bPh)R]_(2)}_(2)[β-Mo_(8)O_(26)]salts withπ-πstacked cations but lacking any(Q^(IV))…O interactions.Moreover,interactions in the system can drive the reorganization of[β-Mo_(8)O_(26)]4-into[α-Mo_(8)O_(26)]^(4-).The halogen-bonded(Q^(IV))…O{(Q(bPh)R)_(x)[β-Mo_(8)O_(26)]^(4-)}(x=2 and 4)assemblies,π-πstacked cationic dimers{(Q(bPh)R)_(2)}^(2+)and complicated associates based on both types of interactions have been the subjects of crystallographic and computational studies.展开更多
The dichalcogenides Ph_(2)Ch_(2)(Ch=S,Se,Te)were cocrystallized with perfluorinated chalcogen bond donors Tol_(2)^(F)Te and Py_(2)^(F)Te(Tol^(F)=4-CF_(3)C_(6)F_(4),PyF=4-NC_(5)F_(4))to obtain the 1:1 cocrystals Tol_(2...The dichalcogenides Ph_(2)Ch_(2)(Ch=S,Se,Te)were cocrystallized with perfluorinated chalcogen bond donors Tol_(2)^(F)Te and Py_(2)^(F)Te(Tol^(F)=4-CF_(3)C_(6)F_(4),PyF=4-NC_(5)F_(4))to obtain the 1:1 cocrystals Tol_(2)^(F)Te·Ph_(2)Ch_(2)(Ch=S 1,Se 2,Te 3)and Py_(2)^(F)Te·Ph_(2)Se_(2)(4).In the X-ray structures of 1-4,heterovalent Te^(Ⅱ)…Ch^(Ⅰ)(Ch=S,Se,Te)chalcogen bonding was identified on consideration of the geometrical parameters and,in addition,based on the results of appropriate density functional theory(DFT)calculations including quantum theory of atoms-in-molecules(QTAIM),noncovalent interaction plot(NCIplot)analysis,molecular electrostatic potential surfaces(MEP),and atoms-in-molecules(AIM)charge analysis.The binding energy in the dimeric structure is in the range between -9.7 and -12.9 kcal mol^(-1),where the contribution of the heterovalent chalcogen bonding ranges from -4.7 to -6.5 kcal mol^(-1).In the Te^(Ⅱ)…Ch^(Ⅰ) moiety,the Te^(Ⅱ) center plays the role of an electrophilic partner,while the chalcogens in the lower oxidation state,1+,exhibit nucleophilic properties.The heterovalent Te^(Ⅱ)…Ch^(Ⅰ)(Ch=Se,Te)chalcogen bonding was thus used for the targeted noncovalent integration of two Ch centers in different oxidation states.展开更多
Fluoroalkene and 1,2-enedichalcogenide represent two classes of valuable structures with wide applications, yet methods for their direct integration remain unknown. Herein, we report a dehalogenative 1,2-dichalcogenat...Fluoroalkene and 1,2-enedichalcogenide represent two classes of valuable structures with wide applications, yet methods for their direct integration remain unknown. Herein, we report a dehalogenative 1,2-dichalcogenation reaction of internal fluoroalkyl alkenes and readily available disulfides, thiols, or diselenides for the synthesis of diverse fluoroalkenyl 1,2-enedichalcogenides. Multiple carbon-halogen bonds in perfluoroalkyl-containing alkenyl iodides can be selectively cleaved under mild and transition-metal-free conditions. This protocol features a broad substrate scope, good scalability, and the ability to modify complex molecules. Mechanistic studies revealed that the key step in the reaction is the formation of a reactive fluoroallene, which is readily attacked by nucleophilic thiolate anions to achieve an unconventional defluorinative chalcogenation.展开更多
Luminescent lanthanide cerium(III) compounds have gathered increasing research interest in both inorganic phosphors and functional molecular complexes. Cerium(III) exhibits broad double-peak emission originating from ...Luminescent lanthanide cerium(III) compounds have gathered increasing research interest in both inorganic phosphors and functional molecular complexes. Cerium(III) exhibits broad double-peak emission originating from 5d excited state 2D3/2 to 4f ground states 2F7/2 and 2F5/2. It is vital to adjust the bandwidth of the emission for different applications like lighting and display, while no regulation between these two peaks in Ce(III) emitters has been reported hitherto. In this work, novel heavy-atom-induced narrow emission is observed in luminescent Ce(III) complexes by adopting imidodiphosphinate ligand with different chalcogen-coordinating sites from O to S, Se, and Te. Not only a new Ce(III) complex with orange–red emission beyond the traditional emission color regions of Ce(III) was obtained, but also the ratio of the two peaks was systematically tuned to achieve the narrowest emission from Ce(III) with a full width at half maximum of 42 nm. Time-dependent density functional theory calculations ascribe the tuning of emission spectra to centroid shift and simultaneously provide the orbital contribution values of different chalcogen atoms to the emission excited state. By extending the coordination atoms from classic oxygen and nitrogen to heavier and softer elements, these results give new insight into luminescence properties and mechanisms of Ce(III) emission.展开更多
Cross-coupling reactions between aryl halides and thiolates or selenolates typically require transition metals,photocatalysts,strong bases,or/and malodorous thiols/selenols,with various mechanisms proposed.This study ...Cross-coupling reactions between aryl halides and thiolates or selenolates typically require transition metals,photocatalysts,strong bases,or/and malodorous thiols/selenols,with various mechanisms proposed.This study aims to leverage a new application of neutral ChB to address these challenges and enable a very simple photoinduced cross-electrophile C—S/Se coupling using readily available chalcogen electrophiles.Mechanistic investigations have revealed the important role of neutral ChB in facilitating single electron transfer processes,thereby enabling the generation of thiolates/selenolates from stable chalcogen electrophiles andα-aminoalkyl radicals,which possess the capability to abstract halogen atoms from aryl iodides.Moreover,the study provided support for the radical nucleophilic substitution mechanism.展开更多
The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodol...The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodology to achieve oxy-, thio-, and seleno-trifluoromethylation remains elusive yet highly desirable. In this study, we report a triarylamine-catalyzed three-component vicinal chalcogen-trifluoromethylation of alkenes under blue light irradiation without the need of transition metal catalyst. This reaction is broadly applicable to oxy, thio, and seleno nucleophiles, facilitating modular access to a diverse array of β-trifluoromethyl alcohols, ethers, thioethers, thiocyanates, and selenocyanates with good yields and predictable regioselectivities (61 examples). Additionally, we demonstrate its application in the late-stage modification of natural products and pharmaceutical compounds. Preliminary mechanistic studies suggest that a catalytic electron donor-acceptor (EDA) complex between triarylamine and the Umemoto reagent is key to enabling the radical/polar crossover process.展开更多
Chalcogen elements,such as sulfur(S),selenium(Se),tellurium(Te)and the interchalcogen compounds,have been studied extensively as cathode materials for the next-generation rechargeable lithium/sodium(Li/Na)batteries.Th...Chalcogen elements,such as sulfur(S),selenium(Se),tellurium(Te)and the interchalcogen compounds,have been studied extensively as cathode materials for the next-generation rechargeable lithium/sodium(Li/Na)batteries.The high energy output of the Li/Na-chalcogen battery originates from the two-electron conversion reaction between chalcogen cathode and alkali metal anode,through which both electrodes are able to deliver high theoretical capacities.The reaction also leads to parasitic reactions that deteriorate the chemical environment in the battery,and different cathode-anode combinations show their own features.In this article,we intend to discuss the fundamental conversion electrochemistry between chalcogen elements and alkali metals and its potential influence,either positive or negative,on the performance of batteries.The strategies to improve the conversion electrochemistry of chalcogen cathode are also reviewed to offer insights into the reasonable design of rechargeable Li/Nachalcogen batteries.展开更多
基金supported by the National Science Fund for Distinguished Young Scholars(21425729)from the National Natural Science Foundation of Chinathe National Special S&T Project on Water Pollution Control and Treatment(2017ZX07107002)+1 种基金China Postdoctoral Science Foundation(2018M640209)the Tianjin Science and Technology Support Key Projects(18YFZCSF00500)~~
文摘The electroactive materials used in the counter electrode(CE)are of great concern as they influence the photovoltaic performances of dye-sensitized solar cells.The main functions of CE materials are collecting electrons from the external circuit and transferring them to the electrolyte and realizing the catalytic reduction of the redox species(I3^– or Co^3+)present in the electrolyte.The research hotspot of CE materials is seeking functional materials that display high efficiency,low cost,and good electrochemical stability and can substitute the benchmark platinum electrode.Chalcogen compounds of cobalt,nickel,and iron have been widely applied as CE materials and exhibit excellent electrocatalytic performances owing to their unique electrical properties,similar energies of adsorption of I atoms as platinum,excellent catalytic activities,and good chemical stabilities.In this review,we trace the developments and performances of chalcogen compounds of iron,cobalt,and nickel as CE materials and present the latest research directions for improving the electrocatalytic performances.We then highlight the optimization strategies for further improving their performances,such as fabrication of architectures,regulation of the components,synthesis of composites containing carbon materials,and elemental doping.
文摘Gas phase carbonylation of methane is studied in the presence of molecular oxygen over pure carbon carriers and carbon supported rhodium chalcogen halides. Activated carbons and fullerene blacks have been used as carbon supports. XPS and IR-spectroscopy data show the formation of rhodium chalcogen halides in solids prepared by different methods. We have found that the productivity of acetic acid by carbon supported rhodium chalcogen halides depends strongly on the carbon carrier and the method of the catalyst preparation. Namely, the catalyst with highest productivity for the acetic acid is prepared by synthesizing the rhodium chalcogen halide over the carbon support followed by thermal destruction. We have also found that rhodium chalcogen halides over activated carbons are more active compared with fullerene supported catalysts.
文摘We have reported a first principles study of structural, mechanical, electronic, and thermoelectric properties of the monoclinic ternary thallium chalcogenes Tl2MQ3(M = Zr, Hf;Q = S, Se, Te). The electronic band structure calculations confirm that all compounds exhibit semiconductor character. Especially, Tl2ZrTe3 and Tl2HfTe3 can be good candidates for thermoelectric materials, having narrow band gaps of 0.169 eV and 0.21 eV, respectively. All of the compounds are soft and brittle according to the second-order elastic constant calculations. Low Debye temperatures also support the softness. We have obtained the transport properties of the compounds by using rigid band and constant relaxation time approximations in the context of Boltzmann transport theory. The results show that the compounds could be considered for room temperature thermoelectric applications(ZT ~ 0.9).
基金supported by funds from scientific research programs of National Academy of Sciences of Ukraine and Ministry of Education and Science of Ukraine
文摘The gas phase methane oxidative carbonylation was studied in the presence of molecular oxygen over silica materials including their mechanical mixtures with rhodium chalcogen chlorides obtained in non-aqueous inorganic media. The formation of Rh4SCl7, Rh4S9Cl2, Rh4SesCl3 and Rh3Se3Cl solids was confirmed by elemental analysis, IR absorption spectroscopy, XPS and X-ray diffraction. Silica, vanadium-, and molybdenum-containing mesoporous molecular sieves have been used as supports. It was found that productivity of oxygenates （methanol, methyl acetate and acetic acid） depends mainly on the method of the catalyst preparation and the type of the support.
基金supported by the construct program of applied characteristic discipline in Hunan University of Science and Engineering,the Technology Plan of Guangdong Province(No. 2019A050510042)the Natural Science Foundation of Hunan Province of China (No. 2021JJ30291)Northwestern Polytechnical University。
文摘Artificial membrane transporters that either use chalcogen bonds to facilitate transmembrane flux of anions or show high selectivity toward perchlorate anions are rare.In this work,we report on one such novel monopeptide-based transporter system,featuring both chalcogen bonds for highly efficient anion transport and high transport selectivity toward ClO_(4)^(-) anions.Structurally,these monopeptide molecules associate with each other via H-bonds to produce H-bonded 1D stack that not only one dimensionally but also directionally aligns the terminal bicyclic thiophene motifs to the same side.Functionally,these well-aligned thiophenes create a sulfur-rich transmembrane pathway,combinatorially fine-tunable to enable anions to efficiently cross the membrane in the increasing activity of Cl^(-)<Br^(-)<NO_(3)^(-)<ClO_(4)^(-) via chalcogen bonds,with EC_(50)values of 0.75,0.40,0.37 and 0.093μmol/L(0.3 mol%relative to lipid molecules),respectively.
基金supported by the Special Scientific Research Fund for Talents Introduced of Hebei Agricultural University (No.YJ2019030)the National Natural Science Foundation of China (Nos.22276042,21906035)the Pearl River Young Talents Program of Guangdong Province (No.2017GC010269)。
文摘Increasing risks of incidental and occupational exposures to two-dimensional transition metal dichalcogenides(2D TMDCs)due to their broad application in various areas raised their public health concerns.While the composition-dependent cytotoxicity of 2D TMDCs has been well-recognized,how the outer chalcogenide atoms and inner transition metal atoms differentially contribute to their perturbation on cell homeostasis at non-lethal doses remains to be identified.In the present work,we compared the autophagy induction and related mechanisms in response to WS_(2),NbS_(2),WSe_(2)and Nb Se_(2)nanosheets exposures in MH-S murine alveolar macrophages.All these 2D TMDCs had comparable physicochemical properties,overall cytotoxicity and capability in triggering autophagy in MH-S cells,but showed outer chalcogen-dependent subcellular localization and activation of autophagy pathways.Specifically,WS_(2)and NbS_(2)nanosheets adhered on the cell surface and internalized in the lysosomes,and triggered m TOR-dependent activation of autophagy.Meanwhile,WSe_(2)and Nb Se_(2)nanosheets had extensive distribution in cytoplasm of MH-S cells and induced autophagy in an m TOR-independent manner.Furthermore,the 2D TMDCs-induced perturbation on autophagy aggravated the cytotoxicity of respirable benzo[a]pyrene.These findings provide a deeper insight into the potential health risk of environmental 2D TMDCs from the perspective of homeostasis perturbation.
文摘This paper presents a versatile method for synthesizing electron-rich polynuclear transition metal clusters with chalcogen bridges and phosphine ligands.The reactions of transition metal complexes(R3P)2MX2(M=Co,Ni;R=Ph,Bu,Et;X=Cl,Br) with bridging reagents Na2Ex (E=S,Se;x=1.2) are described.The geometric and electronic structures of a series of polynuclear transition metal clusters with trianglar M3 units are also discussed.
基金supported by the National Natural Science Foundation of China (22002046 and 22379119)the Qin Chuangyuan High-level Innovative and Entrepreneurial Talent Program of Shaanxi Province (QCYRCXM-2023-045)+1 种基金the Youth Talent Support Program of Xi’an Association for Science and Technology (959202313070)the Young Top-notch Talent Program of Xi’an Jiaotong University (HG6J028)。
文摘The in-situ generated oxyanions at electrochemically reconstructed catalysts from metal-based nonoxide compounds have been proven to significantly accelerate oxygen evolution reaction(OER)kinetics.However,it remains a challenge to retain these self-released oxyanions at reconstructed catalysts,hindering its utilization as a tool to develop efficient OER catalysts.Here,we demonstrate a versatile selftransformed carbonate regulation strategy to efficiently retain the self-released chalcogenate at Co oxyhydroxides reconstructed from carbon-incorporated Co selenides under OER conditions.These selftransformed CO_(3)^(2-)can induce electron accumulation and narrow d bond at Co sites to facilitate the Co3d-O 2p orbital hybridization between Co sites and SeO_(x)^(2-)for enhanced SeO_(x)^(2-)retention,which can accelerate the rate-limiting step for^(*)OOH formation during OER.Relative to CoOOH-SeO_(x)^(2-)with limited SeO_(x)^(2-)residues,CoOOH-CO_(3)^(2-)/SeO_(x)^(2-)with elevated SeO_(x)^(2-)retention by CO_(3)^(2-)regulation exhibited a 5.6-fold increase in current density and a remarkable lower Tafel slope towards OER.This strategy paves a rational avenue to design efficient catalysts for electrooxidation reactions through finely regulating self-released oxyanions at reconstructed structures.
文摘The electronic configuration of central metal atoms in single-atom catalysts(SACs)is pivotal in electrochemical CO_(2) reduction reaction(eCO_(2)RR).Herein,chalcogen heteroatoms(e.g.,S,Se,and Te)were incorporated into the symmetric nickel-nitrogen-carbon(Ni-N_(4)-C)configuration to obtain Ni-X-N_(3)-C(X:S,Se,and Te)SACs with asymmetric coordination presented for central Ni atoms.Among these obtained Ni-X-N_(3)-C(X:S,Se,and Te)SACs,Ni-Se-N_(3)-C exhibited superior eCO_(2)RR activity,with CO selectivity reaching~98% at-0.70 V versus reversible hydrogen electrode(RHE).The Zn-CO_(2) battery integrated with Ni-Se-N_(3)-C as cathode and Zn foil as anode achieved a peak power density of 1.82 mW cm^(-2) and maintained remarkable rechargeable stability over 20 h.In-situ spectral investigations and theoretical calculations demonstrated that the chalcogen heteroatoms doped into the Ni-N_(4)-C configuration would break coordination symmetry and trigger charge redistribution,and then regulate the intermediate behaviors and thermodynamic reaction pathways for eCO_(2)RR.Especially,for Ni-Se-N_(3)-C,the introduced Se atoms could significantly raise the d-band center of central Ni atoms and thus remarkably lower the energy barrier for the rate-determining step of ^(*)COOH formation,contributing to the promising eCO_(2)RR performance for high selectivity CO production by competing with hydrogen evolution reaction.
文摘Growing interest in non-covalent interactions involving chalcogen atoms has been ascribed to their importance in crystal engineering, molecular recognition and macromolecular edifices. The present study is dealing with chalcogen bonds involving divalent Sulphur, Selenium and Tellurium atoms, acting as sigma-hole donors, in small-molecule compounds using the Cambridge Structural Database (CSD) in conjunction with ab initio calculations. Results derived from CSD surveys and computational study revealed that nucleophiles formed complexes with the chalcogen-bond donors R1-X-R2 (X = S, Se or Te). The main forces stabilizing the complexes were chalcogen bonds, enhanced by dispersion interactions. Complexation pattern and energetics show that nucleophile bonding at divalent S, Se and Te atoms is a relatively strong and directed interaction. The bond consists of a charge transfer from a nucleophile atom lone pair to an X-R1 or X-R2 antibonding orbital.
基金supported by the National Natural Science Foundation of China(21771026)the Excellent Discipline Cultivation Project by JHUN(2023XKZ038)+1 种基金the Natural Science Foundation of Jingzhou Science and Technology Bureau(2022CC54-05)“Laboratory for Synthetic Chemistry and Chemical Biology”under the Health@InnoHK Program launched by Innovation and Technology Commission,The Government of Hong Kong Special Administrative Region of the People’s Republic of China.KCL and TCL also acknowledge financial support from a NSFC_RGC Joint Research Scheme(N_CityU111/20)。
文摘Upon irradiation by blue LED(λ>460 nm),the tricyano osmium nitrido complex[Os^(VI)(N)(L)(CN)_(3)]^(-)(OsN)in its excited state readily abstracts chalcogen atoms from the anions NCE^(-)(E=O,S,Se)to give the corresponding metal chalcogenonitrosyls[Os^(Ⅱ)(NuE)(L)(CN)_(3)]^(-)(OsNE)and CN^(-).A similar S atom abstraction also occurs in the photoreaction of OsN with organic sulfide,such as diisopropyl sulfide.
基金support of the Russian Science Foundation(project 21-73-00056)is gratefully acknowledged.Physicochemical studies were performed at the Center for Magnetic Resonance,Center for X-ray Diffraction Studies and Center for Chemical Analysis and Materials Research,while theoretical calculations were performed at the Computational Center(all belonging to Saint Petersburg State University)M.L.K.thanks the Fundação para a Ciência e a Tecnologia(FCT),Portugal,projects UIDB/00100/2020 and UIDP/00100/2020 of Centro de Química Estrutural and LA/P/0056/2020 of the Institute of Molecular Sciences for putting facilities at his disposal.The authors express their gratitude to Dr A.V.Rozhkov for his kind assistance with glove-box manipulations.
文摘The solid-state structures of co-crystals of chalcogenadiazoles(ChDAs)with planar half-lantern Pt_(2)^(Ⅱ) and mononuclear Pt^(Ⅱ)complexes exhibit short Ch…Pt^(Ⅱ)(Ch=Se,Te)contacts that occur between a metal site and the ChDA.The structures demonstrate a unique geometric feature whereby the two deepσ-holes of ChDA are turned away from a d_(z^(2))-nucleophilic PtII site.
基金support(grant number 103922061)Physicochemical studies were performed at the Center for Magnetic Resonance,Center for X-ray Diffraction Studies,and Center for Chemical Analysis and Materials Research(all at Saint Petersburg State University)the RUDN University Scientific Projects Grant System(project no.021342-2-000).
文摘The interactions of tripleσ-(Q^(IV))-hole donating chalconium cations([Q(bPh)R]^(+),when Q=S,Se,and Te)with nucleophilic beta-octamolybdate([β-Mo_(8)O_(26)]^(4-))result in supramolecular association.The main focus of such assembly is onσ-(Q^(IV))-hole recognition by the molybdate in cations with a biphenyl aromatic fragment.This leads to a remarkable diversity of the association patterns producing:(i)neutral 4:1{[Q(bPh)R]^(4)[β-Mo_(8)O_(26)]}complexes with cations stacked byπ-πinteractions;(ii)(Bu_(4)N)^(+),[Q(bPh)R]^(+)and[β-Mo_(8)O_(26)]^(4-)complexes of 2:2:1 stoichiometry withπ-πinteractions;(iii)(Bu4N)+,[Q(bPh)R]+and[β-Mo_(8)O_(26)]^(4-)complexes of a 2:2:1 stoichiometry withoutπ-πinteractions;and(iv){[Q(bPh)R]_(2)}_(2)[β-Mo_(8)O_(26)]salts withπ-πstacked cations but lacking any(Q^(IV))…O interactions.Moreover,interactions in the system can drive the reorganization of[β-Mo_(8)O_(26)]4-into[α-Mo_(8)O_(26)]^(4-).The halogen-bonded(Q^(IV))…O{(Q(bPh)R)_(x)[β-Mo_(8)O_(26)]^(4-)}(x=2 and 4)assemblies,π-πstacked cationic dimers{(Q(bPh)R)_(2)}^(2+)and complicated associates based on both types of interactions have been the subjects of crystallographic and computational studies.
基金supported by the Russian Science Foundation(project 21-73-10030:synthetic experiments,project 19-13-00338:crystal engineering studies)funded by MICIU/AEI of Spain(project PID2020-115637GB-I00 FEDER funds).
文摘The dichalcogenides Ph_(2)Ch_(2)(Ch=S,Se,Te)were cocrystallized with perfluorinated chalcogen bond donors Tol_(2)^(F)Te and Py_(2)^(F)Te(Tol^(F)=4-CF_(3)C_(6)F_(4),PyF=4-NC_(5)F_(4))to obtain the 1:1 cocrystals Tol_(2)^(F)Te·Ph_(2)Ch_(2)(Ch=S 1,Se 2,Te 3)and Py_(2)^(F)Te·Ph_(2)Se_(2)(4).In the X-ray structures of 1-4,heterovalent Te^(Ⅱ)…Ch^(Ⅰ)(Ch=S,Se,Te)chalcogen bonding was identified on consideration of the geometrical parameters and,in addition,based on the results of appropriate density functional theory(DFT)calculations including quantum theory of atoms-in-molecules(QTAIM),noncovalent interaction plot(NCIplot)analysis,molecular electrostatic potential surfaces(MEP),and atoms-in-molecules(AIM)charge analysis.The binding energy in the dimeric structure is in the range between -9.7 and -12.9 kcal mol^(-1),where the contribution of the heterovalent chalcogen bonding ranges from -4.7 to -6.5 kcal mol^(-1).In the Te^(Ⅱ)…Ch^(Ⅰ) moiety,the Te^(Ⅱ) center plays the role of an electrophilic partner,while the chalcogens in the lower oxidation state,1+,exhibit nucleophilic properties.The heterovalent Te^(Ⅱ)…Ch^(Ⅰ)(Ch=Se,Te)chalcogen bonding was thus used for the targeted noncovalent integration of two Ch centers in different oxidation states.
基金the financial support from Natural Science Foundation of Gansu Province(25JRRF004)Jiangsu Provincial University Key Laboratory of Intelligent Medical Sensing Materials and Devicesthe Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX25_1703,recipient:C.Zhang).
文摘Fluoroalkene and 1,2-enedichalcogenide represent two classes of valuable structures with wide applications, yet methods for their direct integration remain unknown. Herein, we report a dehalogenative 1,2-dichalcogenation reaction of internal fluoroalkyl alkenes and readily available disulfides, thiols, or diselenides for the synthesis of diverse fluoroalkenyl 1,2-enedichalcogenides. Multiple carbon-halogen bonds in perfluoroalkyl-containing alkenyl iodides can be selectively cleaved under mild and transition-metal-free conditions. This protocol features a broad substrate scope, good scalability, and the ability to modify complex molecules. Mechanistic studies revealed that the key step in the reaction is the formation of a reactive fluoroallene, which is readily attacked by nucleophilic thiolate anions to achieve an unconventional defluorinative chalcogenation.
基金supported by the National Natural Science Foundation of China(U23A20593,12234001,22071003,62104013,and 92156016)the National Key R&D Program of China(2021YFB3501800,2021YFB3500400,2022YFB3503700,2022YFF0710001,and 2023YFB3506901).
文摘Luminescent lanthanide cerium(III) compounds have gathered increasing research interest in both inorganic phosphors and functional molecular complexes. Cerium(III) exhibits broad double-peak emission originating from 5d excited state 2D3/2 to 4f ground states 2F7/2 and 2F5/2. It is vital to adjust the bandwidth of the emission for different applications like lighting and display, while no regulation between these two peaks in Ce(III) emitters has been reported hitherto. In this work, novel heavy-atom-induced narrow emission is observed in luminescent Ce(III) complexes by adopting imidodiphosphinate ligand with different chalcogen-coordinating sites from O to S, Se, and Te. Not only a new Ce(III) complex with orange–red emission beyond the traditional emission color regions of Ce(III) was obtained, but also the ratio of the two peaks was systematically tuned to achieve the narrowest emission from Ce(III) with a full width at half maximum of 42 nm. Time-dependent density functional theory calculations ascribe the tuning of emission spectra to centroid shift and simultaneously provide the orbital contribution values of different chalcogen atoms to the emission excited state. By extending the coordination atoms from classic oxygen and nitrogen to heavier and softer elements, these results give new insight into luminescence properties and mechanisms of Ce(III) emission.
基金financial support from the National Natural Science Foundation of China(Nos.22173103,52063008)the Academic Talent Plan of Guizhou Normal University(No.Qian Shi Xin Miao[2021]27)the Fundamental Research Funds for the Central Universities and Beijing National Laboratory for Molecular Sciences(BNLMS2023014).
文摘Cross-coupling reactions between aryl halides and thiolates or selenolates typically require transition metals,photocatalysts,strong bases,or/and malodorous thiols/selenols,with various mechanisms proposed.This study aims to leverage a new application of neutral ChB to address these challenges and enable a very simple photoinduced cross-electrophile C—S/Se coupling using readily available chalcogen electrophiles.Mechanistic investigations have revealed the important role of neutral ChB in facilitating single electron transfer processes,thereby enabling the generation of thiolates/selenolates from stable chalcogen electrophiles andα-aminoalkyl radicals,which possess the capability to abstract halogen atoms from aryl iodides.Moreover,the study provided support for the radical nucleophilic substitution mechanism.
基金the financial support provided by the National Natural Science Foundation of China(22361142832,92156025,22271212)the Science and Technology Project of Hebei Education Department Foundation(BJ2025192)We would like to thank Dr.Guosheng Ding,Dr.Kongying Zhu,and Dr.Xiaojuan Deng at the Analysis and Testing Center of Tianjin University for their assistance with NMR testing and analysis.
文摘The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodology to achieve oxy-, thio-, and seleno-trifluoromethylation remains elusive yet highly desirable. In this study, we report a triarylamine-catalyzed three-component vicinal chalcogen-trifluoromethylation of alkenes under blue light irradiation without the need of transition metal catalyst. This reaction is broadly applicable to oxy, thio, and seleno nucleophiles, facilitating modular access to a diverse array of β-trifluoromethyl alcohols, ethers, thioethers, thiocyanates, and selenocyanates with good yields and predictable regioselectivities (61 examples). Additionally, we demonstrate its application in the late-stage modification of natural products and pharmaceutical compounds. Preliminary mechanistic studies suggest that a catalytic electron donor-acceptor (EDA) complex between triarylamine and the Umemoto reagent is key to enabling the radical/polar crossover process.
基金supported by the National Key R&D Program of China(2019YFA0705700)the National Natural Science Foundation of China(21975266,21805062)+1 种基金the Beijing National Laboratory for Molecular Sciences(BNLMS-CXXM-201906)support from the Start-up Funds from the Chinese Academy of Sciences。
文摘Chalcogen elements,such as sulfur(S),selenium(Se),tellurium(Te)and the interchalcogen compounds,have been studied extensively as cathode materials for the next-generation rechargeable lithium/sodium(Li/Na)batteries.The high energy output of the Li/Na-chalcogen battery originates from the two-electron conversion reaction between chalcogen cathode and alkali metal anode,through which both electrodes are able to deliver high theoretical capacities.The reaction also leads to parasitic reactions that deteriorate the chemical environment in the battery,and different cathode-anode combinations show their own features.In this article,we intend to discuss the fundamental conversion electrochemistry between chalcogen elements and alkali metals and its potential influence,either positive or negative,on the performance of batteries.The strategies to improve the conversion electrochemistry of chalcogen cathode are also reviewed to offer insights into the reasonable design of rechargeable Li/Nachalcogen batteries.
