Methane oxidative carbonylation catalyzed by rhodium chalcogen halides over carbon supports

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.

Physical properties of ternary thallium chalcogenes Tl2MQ3（M = Zr, Hf; Q = S, Se, Te） via ab-initio calculations

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).

Catalytic perfomance of rhodium chalcogen halides and rhodium chalcogenides over silica supports in methane oxidative carbonylation

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.

Chalcogen Bonds in Small-Organic Molecule Compounds Derived from the Cambridge Structural Database (CSD)

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.

Perturbation of autophagy pathways in murine alveolar macrophage by 2D TMDCs is chalcogen-dependent

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.

Chalcogen Effect of Atom Substitution on the Properties of Tris(2,4,6-trichlorophenyl)methyl(TTM)Radical

Luminescent open-shell organic radicals have recently been regarded as one of the most potential materials in organic light-emitting diodes(OLEDs).Herein,we have synthesized two new organic radicals,namely tris{4-[4-(tert-butyl)phenoxy]-2,6-dichlorophenyl}methane radical(TTM-O)and tris(4-{[4-(tert-butyl)-phenyl]thio}-2,6-dichlorophenyl)methane radical(TTM-S),by the substitution of chalcogen atom elements at the para position of conventional tris(2,4,6-trichlorophenyl)methyl(TTM)radical moiety.Interestingly,both TTM-O and TTM-S exhibited significantly enhanced photostability compared with the unsubstituted TTM radical parent.Moreover,the chalcogen atom also had a crucial impact on the photoluminescence quantum yield(PLQY)of the radicals,i.e.,the PLQY of TTM-S was greatly enhanced compared to TTM radical while TTM-O was nearly non-emissive.Particularly,TTM-S showed intense PLQY of 37.54%and 185-fold longer photostability than that in cyclohexane solution of TTM.

Chalcogen cathode and its conversion electrochemistry in rechargeable Li/Na batteries

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.

无定形硫属单质分子结构的研究进展

硫属单质(硫、硒、碲)是自然界中一类十分重要的物质,在光电材料、电池及半导体等领域有着广泛的应用.硫属单质均具有晶态和无定形态两种结构形态,其中晶态硫属单质的分子结构已经得到了深入的研究,但无定形硫属单质的分子结构研究还处于初级阶段.为了更好地发掘无定形硫属单质的应用潜力,对其结构与性质进行深入研究十分必要.本文概述了无定形硫属单质分子结构研究方面的最新进展,并展望了未来可能的研究方向.这些工作将有助于更全面地了解无定形硫属单质的性质,并推动其在不同领域中的应用.

A highly active and selective chalcogen bond-mediated perchlorate channel

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.

What Defines a Crystal Structure? Effects of Chalcogen Atoms in 3,7-Bis(methylchalcogeno)benzo[1,2-b:4,5-b′]dichalcogenophene-Based Organic Semiconductors

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.

Air Stable Chalcogen-Doped Rubicenes with Diradical Character

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.

氧族元素间共价单键参与的无机反应机理

结合一些热力学数据和动力学过程,运用亲电和亲核的概念,初步阐释了一些O―O键、S―S键参与的氧化还原反应的机理,并利用Gaussian09程序的计算对一些已有的机理和猜想进行了验证,以此说明无机反应机理的一些规律。

攀西钒钛磁铁矿硫族元素工艺矿物学研究

对攀西钒钛磁铁矿攀枝花、白马、红格、太和4大矿区和选厂的矿样进行了详细的工艺矿物研究,查明了硫族元素在矿石中的赋存状态和分布规律。钴、镍、铜等可综合利用的黄铜矿、镍黄铁矿、方钴矿等矿物平均粒度小于0.074mm,嵌布粒度微细,但与磁黄铁矿和黄铁矿关系密切,大部分赋存于磁黄铁矿和黄铁矿等矿物中,与钛磁铁矿紧密镶嵌的黄铁矿次之,仅少部份以微细矿物的形式赋存于铁相和硅酸盐相矿物中;在选矿过程中进入铁精矿的硫化物也以磁黄铁矿为主。结合硫族元素的利用现状和对矿石中硫族元素的工艺矿物学研究资料,认为在目前的选矿工艺中,以磁黄铁矿和黄铁矿为选别目标,进一步提高以硫精矿为载体的钴、镍、铜元素的精矿品位和回收率,形成可利用含钴镍铜较高品位的硫精矿是可能的,也是符合生产实际的。

环戊二烯类有机金属含硫族化学的新进展

本文系统地综述了环戊二烯类有机过渡金属含硫族（Ｓ，Ｓｅ，Ｔｅ）化学领域的研究现状和进展。参考文献１３６篇。

有机希土金属含硫族化合物的研究进展

本文概述了有机希土（Ｓｃ、Ｙ、Ｌａ－Ｌｕ）含硫族元素（Ｓ、Ｓｅ、Ｔｅ）配位化合物的化学进展，从这类化合物的合成方法、结构特征进行了总结。

Hierarchical N-doped porous carbon hosts for stabilizing tellurium in promoting Al-Te batteries

Aluminum batteries are attractive in electrochemical energy storage due to high energy density and lowcost aluminum,while the energy density is limited for the lack of favorable positive electrode materials to match aluminum negative electrodes.Tellurium positive electrode is intrinsically electrically conductive among chalcogen and holds high theoretical specific capacity(1260.27 mAh g^(-1)) and discharge voltage plateau(~1,5 V).However,the chemical and electrochemical dissolution of Te active materials results in the low material utilization and poor cycling stability.To enhance the electrochemical performance,herein a nitrogen doped porous carbon(N-PC) is derived from zeolite imidazolate framework(ZIF-67)as an effective tellurium host to suppress the undesired shuttle effect.In order to inhibit the volume expansion of N-PC during the charge/discharge process,the reduced graphene oxide(rGO) nanosheets are introduced to form a stable host materials(N-PC-rGO) for stabilizing Te.The physical encapsulation and chemical confinement to soluble tellurium species are achieved.N-PC-rGO-Te positive electrode exhibits an improved initial specific capacity and long-term cycling performance at a current density of 500 mA g^(-1)(initial specific capacity:935.5 mAh g^(-1);after 150 cycles:467.5 mAh g^(-1)), highlighting a promising design strategy for inhibiting chemical and electrochemical dissolution of Te.

含氧族元素过渡链的邻苯二甲腈衍生物的性能

合成了四种含氧族元素过渡链(醚键及硫醚键)的邻苯二甲腈衍生物,红外光谱(FT-IR)和核磁共振氢谱(1H-NMR)证实了它们的结构。氮气氛下的热重分析(TGA)和差示扫描量热分析(DSC)对四种单体的性能进行的表征结果显示,带有氨基的邻苯二甲腈衍生物在高温下出现了自加速热固化现象,不带氨基的邻苯二甲腈衍生物没有出现自加速热固化现象;含硫醚键的邻苯二甲腈衍生物热性能可以优于对应的含醚键衍生物。含硫醚键的邻苯二甲腈衍生物在空气氛中的TGA测试结果显示,由于未发生热氧化交联反应,但热氧化降解明显,其热性能反而更低。

Electron—rich Polynuclear Transition Metal Clusters：I.The Clusters wit

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.

H_2XP…SHY复合物中磷键与硫键的理论研究

用从头算量子化学方法MP2与CCSD(T)研究了H2XP和SHY(X,Y=H,F,Cl,Br)分子的P与S之间形成的磷键X―P…S与硫键Y―S…P的本质与规律以及取代基X与Y对成键的影响.计算结果表明,硫键比磷键强,连接在Lewis酸上的取代基的电负性增大导致形成的磷键或硫键增强,键能增大,对单体的结构和性质的影响也增大;而连接在Lewis碱上的取代基效应则相反.硫键键能为8.37-23.45 kJ·mol-1,最强的硫键结构是Y电负性最大而X电负性最小的HFS…PH3,CCSD(T)计算的键能是16.04 kJ·mol-1;磷键键能为7.54-14.65 kJ·mol-1,最强的磷键结构是X电负性最大而Y电负性最小的H2FP…SH2,CCSD(T)计算的键能是12.52 kJ·mol-1.对磷键与硫键能量贡献较大的是交换与静电作用.分子间超共轭lp(S)-σ*(PX)与lp(P)-σ*(SY)对磷键与硫键的形成起着重要作用,它导致单体的极化,其中硫键的极化效应较大,从而有一定的共价特征.

基于微波光谱的硫中心非共价相互作用的研究进展

硫参与形成的非共价相互作用与众多化学、物理及生命过程密切相关,在超分子化学、生命科学和晶体工程等领域中发挥着重要的作用.几何结构和能量性质是认识硫中心非共价相互作用的重要信息,但是对其进行精确测定在实验和理论方面都颇具挑战.微波光谱是实验测定气相分子几何结构的直接手段,对研究硫中心非共价相互作用具有重要意义.本文介绍了通过微波光谱探究硫中心非共价相互作用的结构和能量特征的研究进展,并指出硫中心非共价相互作用研究中尚待解决的科学问题,讨论了通过微波光谱探究硫中心非共价相互作用的发展趋势.