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
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
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
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
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
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
In the field of supramolecular chemistry,cyclophanes with novel properties are highly sought after since they can be tailored to fulfill specific tasks.In this article,we incorporate chalcogenoviologen-based units int...In the field of supramolecular chemistry,cyclophanes with novel properties are highly sought after since they can be tailored to fulfill specific tasks.In this article,we incorporate chalcogenoviologen-based units into tetracationic cyclophanes,resulting in enhanced host–vip recognition.The cyclophanes can be tuned through the addition of chalcogen bridging atoms—S,Se,and Te—which enhance their rigidity,regulate bond rotation and introduce additional steric bulk.Three cyclophanes containing chalcogen bridging atoms were synthesized and characterized in both the solution and solid states.The energy barriers for their interconversion between syn-and anti-conformations in solution were found to be correlated with chalcogen atom size.The photophysical properties of the cyclophanes are strongly dependent on the chalcogen atomic number,with intersystem crossing rates increasing from S to Se to Te.UV–vis-NIR spectroscopic and fluorometric titrations revealed that the chalcogenoviologenbased cyclophanes exhibit significantly stronger binding with electron-rich vips compared to the well-known,unsubstituted cyclobis(paraquat-pphenylene).This enhancement in binding can be attributed to restricted rotation within the chalcogenoviologen units.This research provides insight into the rational design and tailored synthesis of cationic cyclophanes.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
To understand the effects of chalcogen atoms on the crystal structure of the series of 3,7-bis(methylchalcogeno)benzo[1,2-b:4,5-b′]dichalcogenophene-based organic semiconductors,three benzodifuran derivatives(1—3)an...To understand the effects of chalcogen atoms on the crystal structure of the series of 3,7-bis(methylchalcogeno)benzo[1,2-b:4,5-b′]dichalcogenophene-based organic semiconductors,three benzodifuran derivatives(1—3)and dimethoxy derivatives of benzodithiophene and benzodiselenophene(4 and 7)were newly synthesized to complete the“3×3 matrix”of the oxygen-,sulfur-,and selenium-derivatives(1—9).The crystal structures of 1—9 were classified into four classes,sandwich pitchedπ-stack(1),dimeric(2 and 3),pitchedπ-stack(4,5,7,8,9),and brickwork structure(6 and 9).The causes for the different crystal structures depending on the chalcogen atoms were investigated by the theoretical calculations,indicating that the chalcogen atoms in the core and substituents primarily affected the packing structures.Although the crystal growth in the vapor phase afforded different polymorphs,the relationship between the crystal structure and the carrier transport property was carefully investigated.展开更多
Air stable diradicaloid polycyclic aromatic hydrocarbon(PAH)materials possess unique electronic and magnetic properties for various applications.In general,long conjugated distances between two radical centers are req...Air stable diradicaloid polycyclic aromatic hydrocarbon(PAH)materials possess unique electronic and magnetic properties for various applications.In general,long conjugated distances between two radical centers are required to improve the air stability,thereby complicating the synthetic procedures.Herein,the chalcogen containing rubicenes(O-,S-,and Se-rubicenes)were systematically investigated to understand the chalcogen effects on chalcogen-rubicene physicochemical properties.Impressively,these rubicenes presented unprecedented diradical characterwithin one simple benzene ring and excellent air stabilities.Theirdiradicalcharacterweremanifested by single-crystal X-ray studies,variable-temperature nuclear magnetic resonance,and electron spin resonance.Furthermore,the nucleus independent chemical shifts andthe anisotropy of the induced currentdensity calculations revealed that the formation of diradical was caused by a pro-aromaticity driving force.Importantly,the diradical character of rubicenes are visualizedbyFractionalOccupationNumberWeighted Electron Density(FOD)plots,which present high NFOD values from 1.651 to 1.830.This contribution provided distinctive insights into the structure and property relationship of PAH diradicals.展开更多
Strategic active site organization is imperative for the advancement of effective and long-lasting catalysts of oxygen reduction reactions.However,the controllable multi-active site design is a highly intricate topic ...Strategic active site organization is imperative for the advancement of effective and long-lasting catalysts of oxygen reduction reactions.However,the controllable multi-active site design is a highly intricate topic for catalyst synthesis.Employing pre-trapping and post-activation strategy,Fe-N bonding structure and S,Se functionalized heteroatom are integrated into a conductive porous carbon.In this process,the nitrogen-abundant polymer 1,3,5-triformylbenzene-tris(4-aminophenyl)benzene(Tf-TAPA)adsorbs Fe^(3+)under the intrinsically metal anchoring ability of N atoms and simultaneously in-situ assembles longchain thiophene-S.Subsequently,the Fe^(3+)is transformed into Fe-N_(x)moieties with the conversion of the organic chain to incompletely graphitized carbon.Furthermore,the alteration of the electronic configuration achieved through the introduction of dual-atom S and Se leads to a pronounced enhancement in catalytic efficiency.Benefitting from the Fe-N_(x)bonding structure,dense structural defects,and conductive carbon networks,the resultant Fe-S,Se/NCNs possesses a positive half-wave potential of 0.86 V and a 90%current retention rate,outstripping the Pt/C benchmark.Moreover,the liquid and flexible ZAB driven by Fe-S,Se/NCNs achieves large power densities of 259.7 and 164.7 m W/cm^(2),respectively.This study provides a new comprehension in developing an efficient and stable M-N-C oxygen electrocatalyst.展开更多
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.
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.
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.
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.
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(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 US Department of Energy,Office of Science,Office of Basic Energy Sciences,under Award DE-FG02-99ER14999(M.R.W.)This research made use of the Integrated Molecular Structure Education and Research Center NMR,MS,and X-ray facility at NU,which receives support from the Soft and Hybrid Nanotechnology Experimental(SHyNE)Resource(NSF ECCS-2025633)and NU(C.L.S.).
文摘In the field of supramolecular chemistry,cyclophanes with novel properties are highly sought after since they can be tailored to fulfill specific tasks.In this article,we incorporate chalcogenoviologen-based units into tetracationic cyclophanes,resulting in enhanced host–vip recognition.The cyclophanes can be tuned through the addition of chalcogen bridging atoms—S,Se,and Te—which enhance their rigidity,regulate bond rotation and introduce additional steric bulk.Three cyclophanes containing chalcogen bridging atoms were synthesized and characterized in both the solution and solid states.The energy barriers for their interconversion between syn-and anti-conformations in solution were found to be correlated with chalcogen atom size.The photophysical properties of the cyclophanes are strongly dependent on the chalcogen atomic number,with intersystem crossing rates increasing from S to Se to Te.UV–vis-NIR spectroscopic and fluorometric titrations revealed that the chalcogenoviologenbased cyclophanes exhibit significantly stronger binding with electron-rich vips compared to the well-known,unsubstituted cyclobis(paraquat-pphenylene).This enhancement in binding can be attributed to restricted rotation within the chalcogenoviologen units.This research provides insight into the rational design and tailored synthesis of cationic cyclophanes.
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.
基金financially supported by JSPS KAKENHI Grant Numbers JP19H00906,JP20K22421,and JP20H05865,and the Mitsubishi Foundation.
文摘To understand the effects of chalcogen atoms on the crystal structure of the series of 3,7-bis(methylchalcogeno)benzo[1,2-b:4,5-b′]dichalcogenophene-based organic semiconductors,three benzodifuran derivatives(1—3)and dimethoxy derivatives of benzodithiophene and benzodiselenophene(4 and 7)were newly synthesized to complete the“3×3 matrix”of the oxygen-,sulfur-,and selenium-derivatives(1—9).The crystal structures of 1—9 were classified into four classes,sandwich pitchedπ-stack(1),dimeric(2 and 3),pitchedπ-stack(4,5,7,8,9),and brickwork structure(6 and 9).The causes for the different crystal structures depending on the chalcogen atoms were investigated by the theoretical calculations,indicating that the chalcogen atoms in the core and substituents primarily affected the packing structures.Although the crystal growth in the vapor phase afforded different polymorphs,the relationship between the crystal structure and the carrier transport property was carefully investigated.
基金The work was supported by the NSFC(grant nos.51925306,21774130,and 21905277)National Key R&D Program of China(grant no.2018FYA 0305800)+2 种基金Key Research Program of the Chinese Academy of Sciences(grant no.XDPB08-2)the Strategic Priority Research Program of Chinese Academy of Sciences(grant no.XDB28000000)Fundamental Research Funds for the Central University.DFT results described in this short communication are obtained on the National Super-computing Center in Shenzhen(Shenzhen Cloud Computing Center).
文摘Air stable diradicaloid polycyclic aromatic hydrocarbon(PAH)materials possess unique electronic and magnetic properties for various applications.In general,long conjugated distances between two radical centers are required to improve the air stability,thereby complicating the synthetic procedures.Herein,the chalcogen containing rubicenes(O-,S-,and Se-rubicenes)were systematically investigated to understand the chalcogen effects on chalcogen-rubicene physicochemical properties.Impressively,these rubicenes presented unprecedented diradical characterwithin one simple benzene ring and excellent air stabilities.Theirdiradicalcharacterweremanifested by single-crystal X-ray studies,variable-temperature nuclear magnetic resonance,and electron spin resonance.Furthermore,the nucleus independent chemical shifts andthe anisotropy of the induced currentdensity calculations revealed that the formation of diradical was caused by a pro-aromaticity driving force.Importantly,the diradical character of rubicenes are visualizedbyFractionalOccupationNumberWeighted Electron Density(FOD)plots,which present high NFOD values from 1.651 to 1.830.This contribution provided distinctive insights into the structure and property relationship of PAH diradicals.
基金supported by Distinguished Young Scholar Fund Project of Hunan Province Natural Science Foundation(No.2023JJ10041)the Hunan Provincial Education Office Foundation of China(No.21B0147)+3 种基金the Science and Technology Program of Xiangtan(No.GX-ZD20211004)the Hunan Provincial united foundation(No.2022JJ50136)the National Natural Science Foundation of China(No.52003230)the Science and Technology Innovation Program of Hunan Province(No.2021RC2091)。
文摘Strategic active site organization is imperative for the advancement of effective and long-lasting catalysts of oxygen reduction reactions.However,the controllable multi-active site design is a highly intricate topic for catalyst synthesis.Employing pre-trapping and post-activation strategy,Fe-N bonding structure and S,Se functionalized heteroatom are integrated into a conductive porous carbon.In this process,the nitrogen-abundant polymer 1,3,5-triformylbenzene-tris(4-aminophenyl)benzene(Tf-TAPA)adsorbs Fe^(3+)under the intrinsically metal anchoring ability of N atoms and simultaneously in-situ assembles longchain thiophene-S.Subsequently,the Fe^(3+)is transformed into Fe-N_(x)moieties with the conversion of the organic chain to incompletely graphitized carbon.Furthermore,the alteration of the electronic configuration achieved through the introduction of dual-atom S and Se leads to a pronounced enhancement in catalytic efficiency.Benefitting from the Fe-N_(x)bonding structure,dense structural defects,and conductive carbon networks,the resultant Fe-S,Se/NCNs possesses a positive half-wave potential of 0.86 V and a 90%current retention rate,outstripping the Pt/C benchmark.Moreover,the liquid and flexible ZAB driven by Fe-S,Se/NCNs achieves large power densities of 259.7 and 164.7 m W/cm^(2),respectively.This study provides a new comprehension in developing an efficient and stable M-N-C oxygen electrocatalyst.
