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1.
Ying Wang Dr. Tian‐Wei Wang Hong‐Ping Xiao Yi‐Zhi Li Dr. You Song Xiao‐Zeng You Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(31):7648-7655
By using cyclohexane‐1,2‐diamine (chxn), Ni(ClO4)2 ? 6H2O and Na3[Mo(CN)8] ? 4H2O, a 3D diamond‐like polymer {[NiII(chxn)2]2[MoIV(CN)8] ? 8H2O}n ( 1 ) was synthesised, whereas the reaction of chxn and Cu(ClO4)2 ? 6H2O with Na3[MV(CN)8] ? 4H2O (M=Mo, W) afforded two isomorphous graphite‐like complexes {[CuII(chxn)2]3[MoV(CN)8]2 ? 2H2O}n ( 2 ) and {[CuII(chxn)2]3[WV(CN)8]2 ? 2H2O}n ( 3 ). When the same synthetic procedure was employed, but replacing Na3[Mo(CN)8] ? 4H2O by (Bu3NH)3[Mo(CN)8] ? 4H2O (Bu3N=tributylamine), {[CuII(chxn)2MoIV(CN)8][CuII(chxn)2] ? 2H2O}n ( 4 ) was obtained. Single‐crystal X‐ray diffraction analyses showed that the framework of 4 is similar to 2 and 3 , except that a discrete [Cu(chxn)2]2+ moiety in 4 possesses large channels of parallel adjacent layers. The experimental results showed that in this system, the diamond‐ or graphite‐like framework was strongly influenced by the inducement of metal ions. The magnetic properties illustrate that the diamagnetic [MoIV(CN)8] bridges mediate very weak antiferromagnetic coupling between the NiII ions in 1 , but lead to the paramagnetic behaviour in 4 because [MoIV(CN)8] weakly coordinates to the CuII ions. The magnetic investigations of 2 and 3 indicate the presence of ferromagnetic coupling between the CuII and WV/MoV ions, and the more diffuse 5d orbitals lead to a stronger magnetic coupling interaction between the WV and CuII ions than between the MoV and CuII ions. 相似文献
2.
《Journal of Coordination Chemistry》2012,65(4):627-639
Two polyoxometalate-based inorganic metal-organic hybrid supramolecular complexes [Cu(2,2′-bpy)2]2[VIV 2MoV 5MoVI 7O38(PO4)] (1) (2,2′-bpy?=?2,2′-bipyridine) and [Cu(2,2′-bpy)2]2[MoVMoVI 11O36(PO4)]?·?3H2O (2), have been hydrothermally prepared and structurally characterized by single-crystal X-ray diffraction. Both complexes are constructed from polyoxoanions (the bivanadyl capped α-Keggin polymolybdate anion [VIV 2MoV 5MoVI 7O38(PO4)]4? for 1 and the reduced 12-molybdophosphate anion [MoVMoVI 11O36(PO4)]4? for 2) and copper(II) complex cations [Cu(2,2′-bpy)2]2+, forming two-dimensional (2D) layer network structures, in which the polyoxoanion and the complex fragment cation connect with each other through Cu?···?Opolyoxoanion short contact weak interactions, which mediate ferromagnetic interaction. 相似文献
3.
The Enhancement on Proton Conductivity of Stable Polyoxometalate‐Based Coordination Polymers by the Synergistic Effect of MultiProton Units 下载免费PDF全文
Dr. Jing Li Dr. Xue‐Li Cao Dr. Yuan‐Yuan Wang Dr. Shu‐Ran Zhang Dr. Dong‐Ying Du Dr. Jun‐Sheng Qin Prof. Shun‐Li Li Prof. Zhong‐Min Su Prof. Ya‐Qian Lan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(27):9299-9304
Two novel polyoxometalate (POM)‐based coordination polymers, namely, [Co(bpz)(Hbpz)][Co(SO4)0.5(H2O)2(bpz)]4 [PMoVI8MoV4VIV4O42]?13 H2O ( NENU‐530 ) and [Ni2(bpz)(Hbpz)3(H2O)2][PMoVI8MoV4VIV4O44]?8 H2O ( NENU‐531 ) (H2bpz=3,3′,5,5′‐tetramethyl‐4,4′‐bipyrazole), were isolated by hydrothermal methods, which represented 3D networks constructed by POM units, the protonated ligand and sulfate group. In contrast with most POM‐based coordination polymers, these two compounds exhibit exceptional excellent chemical and thermal stability. More importantly, NENU‐530 shows a high proton conductivity of 1.5×10?3 S cm?1 at 75 °C and 98 % RH, which is one order of magnitude higher than that of NENU‐531 . Furthermore, structural analysis and functional measurement successfully demonstrated that the introduction of sulfate group is favorable for proton conductivity. Herein, the syntheses, crystal structures, proton conductivity, and the relationship between structure and property are presented. 相似文献
4.
Anne Dolbecq Dr. Jean‐Daniel Compain Pierre Mialane Dr. Jérôme Marrot Dr. Francis Sécheresse Prof. Bineta Keita Dr. Luis Roberto Brudna Holzle Dr. Frédéric Miserque Dr. Louis Nadjo Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(3):733-741
Two new compounds based on O3PCH2PO34? ligands and {MoV2O4} dimeric units have been synthesized and structurally characterized. The dodecanuclear MoV polyoxomolybdate species in (NH4)18[(MoV2O4)6(OH)6(O3PCH2PO3)6]?33 H2O ( 1 ) is a cyclohexane‐like ring in a chair conformation with pseudo S6 symmetry. In the solid state, the wheels align side by side, thus delimiting large rectangular voids. The hexanuclear anion in Na8[(MoV2O4)3(O3PCH2PO3)3(CH3AsO3)]? 19 H2O ( 2 ) has a triangular framework and encapsulates a methylarsenato ligand. 31P NMR spectroscopic analysis revealed the stability of 2 in various aqueous media, whereas the stability of 1 depends on the nature of the cations present in solution. It has been evidenced that the transformation of 1 into 2 occurs in the presence of CH3AsO32? ions. This behavior shows that 1 can be used as a new precursor for the synthesis of MoV/diphosphonate systems. The two complexes were very efficient both as reductants of Pt and Pd metallic salts and as capping agents for the resulting Pt0 and Pd0 nanoparticles. The size of the obtained nanoparticles depends both on the nature of the polyoxometalate (POM; i.e., 1 or 2 ) and on the [metallic salt]/[POM] ratio. In all cases, X‐ray photoelectron spectroscopy (XPS) measurements have revealed the presence of MoVI species that stabilize the nanoparticles and the absence of MoV moieties. Diffuse‐reflectance FTIR spectra of the Pt nanoparticles show that the capping MoVI POMs are identical for both systems and contain the diphosphonato ligand. The colloidal solutions do not show any precipitate and the nanoparticles remain well‐dispersed for several months. The electrochemical reduction of MoV species was studied for 2 . Cyclic voltammetry alone and electrochemical quartz crystal microbalance coupled with cyclic voltammetry show the deposition of a film on the electrode surface during this reduction. 相似文献
5.
P. S. Berdonosov P. Schmidt O. A. Dityat'yev V. A. Dolgikh P. Lightfoot Michael Ruck 《无机化学与普通化学杂志》2004,630(10):1395-1400
Pale pink crystals of Nd2(SeO3)2(SeO4) · 2H2O were synthesized under hydrothermal conditions from H2SeO3 and Nd2O3 at about 200 °C. X‐ray diffraction on powder and single‐crystals revealed that the compound crystallizes with the monoclinic space group C 2/c (a = 12.276(1) Å, b = 7.0783(5) Å, c = 13.329(1) Å, β = 104.276(7)°). The crystal structure of Nd2(SeO3)2(SeO4) · 2H2O is an ordered variant of the corresponding erbium compound. Eight oxygen atoms coordinate the NdIII atom in the shape of a bi‐capped trigonal prism. The oxygen atoms are part of pyramidal (SeIVO3)2? groups, (SeVIO4)2? tetrahedra and water molecules. The [NdO8] polyhedra share edges to form chains oriented along [010]. The selenate ions link these chains into layers parallel to (001). The layers are interconnected by the selenite ions into a three‐dimensional framework. The dehydration of Nd2(SeO3)2(SeO4) · 2H2O starts at 260 °C. The thermal decomposition into Nd2SeO5, SeO2 and O2 at 680 °C is followed by further loss of SeO2 leaving cubic Nd2O3. 相似文献
6.
A new metal‐oxo cluster supported transition metal complex, [Cu(en)2(H2O)]2[Cu(en)2]0.5[MoVI8VIV6VVO42{Cu(en)2}], has been synthesized under hydrothermal conditions. Its structure was determined by single‐crystal X‐ray diffraction. The compound crystallizes in the triclinic system, space group (No. 2), a = 12.245(5), b = 12.669(5), c = 20.949(8) Å, α = 77.120(13), β = 78.107(17), γ = 65.560(14)°, V = 2860(2) Å3, Z = 2. The metal‐oxo cluster contains a novel bicapped a‐Keggin structure unit and a [Cu(en)2]2+ unit covalently bonded to the [Mo8V7O42]7? cluster. 相似文献
7.
Modular Molecules: Site‐Selective Metal Substitution,Photoreduction, and Chirality in Polyoxometalate Hybrids 下载免费PDF全文
Michele Vonci Fateme Akhlaghi Bagherjeri Peter D. Hall Dr. Robert W. Gable Athanasios Zavras Prof. Richard A. J. O'Hair Yuping Liu Dr. Jie Zhang Dr. Matthew R. Field Dr. Matthew B. Taylor Prof. Johan Du Plessis Prof. Gary Bryant Prof. Mark Riley Dr. Lorenzo Sorace Pablo A. Aparicio Dr. Xavier López Prof. Josep M. Poblet Dr. Chris Ritchie Dr. Colette Boskovic 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(43):14102-14111
The first members of a promising new family of hybrid amino acid–polyoxometalates have emerged from a search for modular functional molecules. Incorporation of glycine (Gly) or norleucine (Nle) ligands into an yttrium‐tungstoarsenate structural backbone, followed by crystallization with p‐methylbenzylammonium (p‐MeBzNH3+) cations, affords (p‐MeBzNH3)6K2(GlyH)[AsIII4(YIIIWVI3)WVI44YIII4O159(Gly)8‐ (H2O)14] ? 47 H2O ( 1 ) and enantiomorphs (p‐MeBzNH3)15(NleH)3 [AsIII4(MoV2MoVI2)WVI44YIII4O160(Nle)9(H2O)11][AsIII4(MoVI2WVI2)‐ WVI44YIII4O160(Nle)9(H2O)11] (generically designated 2 : L ‐Nle, 2 a ; D ‐Nle, 2 b ). An intensive structural, spectroscopic, electrochemical, magnetochemical and theoretical investigation has allowed the elucidation of site‐selective metal substitution and photoreduction of the tetranuclear core of the hybrid polyanions. In the solid state, markedly different crystal packing is evident for the compounds, which indicates the role of noncovalent interactions involving the amino acid ligands. In solution, mass spectrometric and small‐angle X‐ray scattering studies confirm maintenance of the structure of the polyanions of 2 , while circular dichroism demonstrates that the chirality is also maintained. The combination of all of these features in a single modular family emphasizes the potential of such hybrid polyoxometalates to provide nanoscale molecular materials with tunable properties. 相似文献
8.
Ronny Neumann Prof. Daniella Goldfarb Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(33):10014-10020
An in‐depth spectroscopic EPR investigation of a key intermediate, formally notated as [PVIVVVMo10O40]6? and formed in known electron‐transfer and electron‐transfer/oxygen‐transfer reactions catalyzed by H5PV2Mo10O40, has been carried out. Pulsed EPR spectroscopy have been utilized: specifically, W‐band electron–electron double resonance (ELDOR)‐detected NMR and two‐dimensional (2D) hyperfine sub‐level correlation (HYSCORE) measurements, which resolved 95Mo and 17O hyperfine interactions, and electron–nuclear double resonance (ENDOR), which gave the weak 51V and 31P interactions. In this way, two paramagnetic species related to [PVIVVVMo10O40]6? were identified. The first species (30–35 %) has a vanadyl (VO2+)‐like EPR spectrum and is not situated within the polyoxometalate cluster. Here the VO2+ was suggested to be supported on the Keggin cluster and can be represented as an ion pair, [PVVMo10O39]8?[VIVO2+]. This species originates from the parent H5PV2Mo10O40 in which the vanadium atoms are nearest neighbors and it is suggested that this isomer is more likely to be reactive in electron‐transfer/oxygen‐transfer reaction oxidation reactions. In the second (70–65 %) species, the VIV remains embedded within the polyoxometalate framework and originates from reduction of distal H5PV2Mo10O40 isomers to yield an intact cluster, [PVIVVVMo10O40]6?. 相似文献
9.
Two new organic–inorganic hybrid compounds, [Cu(phen)(prz)]2[PMoV1MoVI7VIV2VV4O42]·4H2O (1) and [Ag2(phen)4]2[PMoV1MoVI7VIV2VV4O42] (2) (phen = 1,10-phenanthroline, prz = pyrazine), have been synthesized and characterized by IR, XPS, XRD, UV–vis, fluorescent spectra analyses, elemental analyses, X-ray diffraction analyses, TG analyses, and cyclic voltammetric measurements. Both compounds are formed by Keggin POM cores and transition metal fragments. Compound 1 exhibits an unprecedented 1-D chain structure constructed from [PMoV1MoVI7VIV2VV4O42]4? and [Cu(phen)(prz)]2+ in the –A–B↑–C–B↓– linking mode. Compound 2 shows a supramolecular structure formed by [PMoV1MoVI7VIV2VV4O42]4? and [Ag2(phen)4]2+. 相似文献
10.
Tetraammonium cadmium dihydrogenselenite(IV) diselenate(VI), (NH4)4Cd(HSeIVO3)2(SeVIO4)2, is the third example of a compound containing both hydrogen selenite and selenate anions, and has a new structure type. It contains kröhnkite‐like heteropolyhedral chains in which CdO6 octahedra are linked via bridging HSeO3 groups, having their remaining two trans apices decorated by SeO4 groups. The charge‐balancing NH4 groups are involved in weak hydrogen bonding, whereas the H atom of the HSeO3 group provides a strong hydrogen bond [O⋯O = 2.614 (5) Å]. The average Cd—O bond length is 2.298 Å. All atoms are on general positions except Cd (on ). Relations to the kröhnkite‐type compounds Na2Mg(SO3)·2H2O, Ba2CoCl2(SeO3)2 and Ba2Ca(HPO4)2(H2PO4)2, and to the mineral curetonite are discussed. Unit‐cell data are given for an isotypic MnII analogue. 相似文献
11.
Clément Camp Victor Mougel Dr. Jacques Pécaut Prof. Laurent Maron Dr. Marinella Mazzanti 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(51):17528-17540
Two new arene inverted‐sandwich complexes of uranium supported by siloxide ancillary ligands [K{U(OSi(OtBu)3)3}2(μ‐η6:η6‐C7H8)] ( 3 ) and [K2{U(OSi(OtBu)3)3}2(μ‐η6:η6‐C7H8)] ( 4 ) were synthesized by the reduction of the parent arene‐bridged complex [{U(OSi(OtBu)3)3}2(μ‐η6:η6‐C7H8)] ( 2 ) with stoichiometric amounts of KC8 yielding a rare family of inverted‐sandwich complexes in three states of charge. The structural data and computational studies of the electronic structure are in agreement with the presence of high‐valent uranium centers bridged by a reduced tetra‐anionic toluene with the best formulation being UV–(arene4?)–UV, KUIV–(arene4?)–UV, and K2UIV–(arene4?)–UIV for complexes 2 , 3 , and 4 respectively. The potassium cations in complexes 3 and 4 are coordinated to the siloxide ligands both in the solid state and in solution. The addition of KOTf (OTf=triflate) to the neutral compound 2 promotes its disproportionation to yield complexes 3 and 4 (depending on the stoichiometry) and the UIV mononuclear complex [U(OSi(OtBu)3)3(OTf)(thf)2] ( 5 ). This unprecedented reactivity demonstrates the key role of potassium for the stability of these complexes. 相似文献
12.
Valeriu Mereacre Ayuk M. Ako Muhammad Nadeem Akhtar Anja Lindemann Christopher E. Anson Annie K. Powell 《Helvetica chimica acta》2009,92(11):2507-2524
Reactions of CeIII(NO3)3?6 H2O or (NH4)2[CeIV(NO3)6] with Mn‐containing starting materials result in seven novel polynuclear Ce or Ce/Mn complexes with pivalato (tBuCO ) and, in most cases, auxiliary N,O‐ or N,O,O‐donor ligands. With nuclearities ranging from 6–14, the compounds present aesthetically pleasing structures. Complexes [CeIV6(μ3‐O)4(μ3‐OH)4(μ‐O2CtBu)12] ( 1 ), [CeIV6MnIII4(μ4‐O)4(μ3‐O)4(O2CtBu)12(ea)4(OAc)4]?4 H2O?4 MeCN (ea?=2‐aminoethanolato; 2 ), [CeIV6MnIII8(μ4‐O)4(μ3‐O)8(pye)4(O2CtBu)18]2[CeIV6(μ3‐O)4(μ3‐OH)4(O2CtBu)10(NO3)4] [CeIII(NO3)5(H2O)]?21 MeCN (pye?=pyridine‐2‐ethanolato; 3 ), and [CeIV6CeIII2MnIII2(μ4‐O)4(μ3‐O)4(tbdea)2(O2CtBu)12(NO3)2(OAc)2]?4 CH2Cl2 (tbdea2?=2,2′‐(tert‐butylimino]bis[ethanolato]; 4 ) all contain structures based on an octahedral {CeIV6(μ3‐O)8} core, in which many of the O‐atoms are either protonated to give (μ3‐OH)? hydroxo ligands or coordinate to further metal centers (MnIII or CeIII) to give interstitial (μ4‐O)2? oxo bridges. The decanuclear complex [CeIV8CeIIIMnIII(μ4‐O)3(μ3‐O)3(μ3‐OH)2(μ‐OH)(bdea)4(O2CtBu)9.5(NO3)3.5(OAc)2]?1.5 MeCN (bdea2?=2,2′‐(butylimino]bis[ethanolato]; 5 ) contains a rather compact CeIV7 core with the CeIII and MnIII centers well‐separated from each other on the periphery. The aggregate in [CeIV4MnIV2(μ3‐O)4(bdea)2(O2CtBu)10(NO3)2]?4 MeCN ( 6 ) is based on a quasi‐planar {MnIV2CeIV4(μ3‐O)4} core made up of four edge‐sharing {MnIVCeIV2(μ3‐O)} or {CeIV3(μ3‐O)} triangles. The structure of [CeIV3MnIV4MnIII(μ4‐O)2(μ3‐O)7(O2CtBu)12(NO3)(furan)]?6 H2O ( 7 ?6 H2O) can be considered as {MnIV2CeIV2O4} and distorted {MnIV2MnIIICeIVO4} cubane units linked through a central (μ4‐O) bridge. The Ce6Mn8 equals the highest nuclearity yet reported for a heterometallic Ce/Mn aggregate. In contrast to most of the previously reported heterometallic Ce/Mn systems, which contain only CeIV and either MnIV or MnIII, some of the aggregates presented here show mixed valency, either MnIV/MnIII (see 7 ) or CeIV/CeIII (see 4 and 5 ). Interestingly, some of the compounds, including the heterovalent CeIV/CeIII 4 , could be obtained from either CeIII(NO3)3?6 H2O or (NH4)2[CeIV(NO3)6] as starting material. 相似文献
13.
Polyoxometalates (POMs)containingKegginmoi etieshavebeenreceivingextensiveattentioninrecentyearsowingtotheirgreatfundamentalandpracticalinter est .1Especiallytheunusualelectronicproperty (highnegativecharges) ,oneofthemostimportantpropertiesofPOMs ,haspoten… 相似文献
14.
Self‐Recognition Between Two Almost Identical Macroions During Their Assembly: The Effects of pH and Temperature 下载免费PDF全文
Fadi Haso Dr. Dong Li Somenath Garai Dr. Joseph M. Pigga Prof. Dr. Tianbo Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(38):13234-13239
Two Keplerate‐type macroions, [MoVI72FeIII30O252‐ (CH3COO)12{Mo2O7(H2O)}2{H2Mo2O8(H2O)}(H2O)91]?ca. 150 H2O= {Mo72Fe30} and [{Na(H2O)12}?{MoVI72CrIII30O252(CH3COO)19‐ (H2O)94}]?ca. 120 H2O= {Mo72Cr30} , with identical size and shape but different charge density, can self‐assemble into spherical “blackberry”‐like structures in aqueous solution by means of electrostatic interactions. These two macroanions can self‐recognize each other and self‐assemble into two separate types of homogeneous blackberries in their mixed dilute aqueous solution, in which they carry ?7 and ?5 net charges, respectively. Either adjusting the solution pH or raising temperature is expected to make the self‐recognition more difficult, by making the charge densities of the two clusters closer, or by decreasing the activation energy barrier for the blackberry formation, respectively. Amazingly, the self‐recognition behavior remains, as confirmed by dynamic and static light scattering, TEM, and energy dispersive spectroscopy techniques. The results prove that the self‐recognition behavior of the macroions due to the long‐range electrostatic interaction is universal and can be achieved when only minimum differences exist between two types of macroanions. 相似文献
15.
Assembly of Large Purely Inorganic Ce‐Stabilized/Bridged Selenotungstates: From Nanoclusters to Layers 下载免费PDF全文
Wei‐Chao Chen Prof. Chao Qin Prof. Yang‐Guang Li Prof. Hong‐Ying Zang Kui‐Zhan Shao Prof. Zhong‐Min Su Prof. En‐Bo Wang 《化学:亚洲杂志》2015,10(5):1184-1191
A versatile one‐pot strategy was used to synthesize two large, purely inorganic selenotungstates, nanocluster K6Na16[Ce6Se6W67O230(OH)6(H2O)17]?47 H2O ( 1 ) and layer K9Na5Ce(H2O)4[Ce6Se10W51O187(OH)7(H2O)18]?45 H2O ( 2 ), by combining cerium centers and SeO32? heteroanion templates. Compound 1 displays a Ce‐stabilized hexameric nanocluster with one rhombus‐like {W4O15(OH)3} unit in the center, whereas compound 2 is the first example of a Ce‐bridged layer selenotungstate network based on linkage of the unusual {Ce6Se10W51O187(OH)7(H2O)18} clusters and additional Ce(H2O)4 fragments via Ce‐O‐Se bridges. The compounds were characterized by elemental analyses, IR spectroscopy, thermogravimetric analyses, powder and single‐crystal X‐ray diffraction, and electrospray ionization mass spectrometry. Moreover, the electrochemical property of compound 1 was also investigated. 相似文献
16.
An organic‐inorganic heterogeneous catalyst based on Keplerate polyoxometalates for oxidation of dibenzothiophene derivatives with Hydrogen peroxide 下载免费PDF全文
Reza Fareghi‐Alamdari Negar Zekri Ahmad Jamali Moghadam Khadijeh Tavakoli Hafshajani Mostafa Riahi Farsani 《应用有机金属化学》2018,32(4)
An organic‐inorganic material (NH4)2(MimAM)40[Mo132O372(CH3COO)30(H2O)72] have been synthesized by reacting [(NH4)42[MoVI72 MoV60O372(CH3COO)30(H2O)72] with the ionic liquid 3‐Aminoethyl‐1‐methylimidazolium bromide. The catalyst showed remarkably a high catalytic performance in the oxidation of dibenzothiophene (DBT) derivatives with H2O2 35% as a safe and green oxidant. The main parameters affecting the process including catalyst, acid additive, hydrogen peroxide amounts and temperature have been investigated in detail. Sulfur removal of DBT in n‐heptane reached to 98.3% yield at 40 °C using 2.5 mmol H2O2 and 100 mg of (NH4)2(MimAM)40[Mo132O372(CH3COO)30(H2O)72] after 90 min. Under the optimal conditions, BT (benzothiophene), DBT (dibenzothiophene) and 4,6‐DMDBT (4,6‐dimethyl‐dibenzothiophene) achieved high desulfurization efficiency. Our results showed that the reactivity order of different model sulfur compounds are thiophene <4,6‐dimethyl dibenzothiophene< dibenzothiophene. The catalysts could be easily separated from the reaction solution by simple filtration and recycled for several times without loss of activity. 相似文献
17.
A. A. Ostroushko V. Yu. Korotaev M. O. Tonkushina V. A. Vazhenin M. Yu. Artemov S. Yu. Men’shikov I. B. Kutyashev 《Russian Journal of Inorganic Chemistry》2011,56(2):276-281
Molybdenum polyoxometallates with the buckyball structure, ((NH4)42[Mo72VIMo60VO372(H3CCOO)30(H2O)72] · 30H3CCOONH4 · 250H2O (I), (NH4)42[Mo72VIMo60VO372(ClCH2COO)30(H2O)72)] · 250H2O · 15ClCH2COONa (II), in particular, as parts of polymer-containing compositions were studied by EPR, NMR, IR, and Raman spectroscopy. The structural
and chemical aspects responsible for the formation of the observed spectra were considered. 相似文献
18.
Masaki Takehara Masato Hashimoto 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(1):37-40
The unit‐cell parameters of the three title salts, namely, tripotassium, K3[Mo2(CHO2)O3(O2)4], trirubidium, Rb3[Mo2(CHO2)O3(O2)4], and triammonium μ‐(formato‐κ2O:O′)‐μ‐oxido‐bis[oxidobis(peroxido‐κ2O,O′)molybdate(VI)], (NH4)3[Mo2(CHO2)O3(O2)4], which were all crystallized at pH 3, are quite similar, but the potassium and rubidium salt structures are noncentrosymmetric, whereas that of the ammonium salt is centrosymmetric. Formate acts as an O:O′‐bridging ligand in the complex anion and is bound to a μ‐oxido‐bis(oxidodiperoxidomolybdate) unit. 相似文献
19.
Incorporation of Sulfate or Selenate Groups into Oxotellurates(IV): I. Calcium,Cadmium, and Strontium Compounds 下载免费PDF全文
Seven new mixed oxochalcogenate compounds in the systems MII/XVI/TeIV/O/(H), (MII = Ca, Cd, Sr; XVI = S, Se) were obtained under hydrothermal conditions (210 °C, one week). Crystal structure determinations based on single‐crystal X‐ray diffraction data revealed the compositions Ca3(SeO4)(TeO3)2, Ca3(SeO4)(Te3O8), Cd3(SeO4)(Te3O8), Cd3(H2O)(SO4)(Te3O8), Cd4(SO4)(TeO3)3, Cd5(SO4)2(TeO3)2(OH)2, and Sr3(H2O)2(SeO4)(TeO3)2 for these phases. Peculiar features of the crystal structures of Ca3(SeO4)(TeO3)2, Ca3(SeO4)(Te3O8), Cd3(SeO4)(Te3O8), Cd3(H2O)(SO4)(Te3O8), and Sr3(H2O)2(SeO4)(TeO3)2 are metal‐oxotellurate(IV) layers connected by bridging XO4 tetrahedra and/or by hydrogen‐bonding interactions involving hydroxyl or water groups, whereas Cd4(SO4)(TeO3)3 and Cd5(SO4)2(TeO3)2(OH)2 crystallize as framework structures. Common to all crystal structures is the stereoactivity of the TeIV electron lone pair for each oxotellurate(IV) unit, pointing either into the inter‐layer space, or into channels and cavities in the crystal structures. 相似文献
20.
Rational self‐assembly of Sb2O3 and Na2WO4, or (NH4)18[NaSb9W21O86] with transition‐metal ions (Mn2+, Cu2+, Co2+), in aqueous solution under controlled conditions yield a series of sandwich type complexes, namely, Na2H2[Mn2.5W1.5(H2O)8(B‐β‐SbW9O33)2]?32 H2O (1) , Na4H7[Na3(H2O)6Mn3(μ‐OAc)2(B‐α‐SbW9O33)2]?20 H2O (OAc=acetate anion) (2) , NaH8[Na2Cu4Cl(B‐α‐SbW9O33)2]?21 H2O (3) , Na8K[Na2K(H2O)2{Co(H2O)}3(B‐α‐SbW9O33)2]? 10 H2O (4) , and Na5H[{Co(H2O)2}3W(H2O)2(B‐β‐SbW9O33)2]?11.5 H2O (5) . These structures are determined by using the X‐ray diffraction technique and further characterized by obtaining IR spectra and performing elemental analysis. Structure analysis reveals that polyoxoanions in 1 and 5 comprise of two [B‐β‐SbW9O33]9? building units, whereas 2 , 3 , and 4 consist of two isomerous [B‐α‐SbW9O33]9? building blocks, which are all linked by different transition‐metal ions (Mn2+, Cu2+, or Co2+) with different quantitative nuclearity. It should be noted that compound 2 represents the first one‐dimensional sinusoidal chain based on sandwich like tungstoantimonate building blocks through the carboxylate‐bridging ligands. Additionally, 3 is constructed from sandwiched anions [Na2Cu4Cl(B‐α‐SbW9O33)2]9? linked to each other to form an infinitely extended 2D network, whereas 5 shows an interesting 3D framework built up from offset sandwich type polyoxoanion [{Co(H2O)2}3W(H2O)2(B‐β‐SbW9O33)2]6? linked by Co2+ and Na+ ions. EPR studies performed at 110 K and room temperature reveal that the metal cations (Mn2+, Cu2+, Co2+) reside in a square‐pyramidal geometry in 2 , 3 , and 4 . The magnetic behavior of 1 – 4 suggests the presence of weak antiferromagnetic coupling interactions between magnetic metal centers with the exchange integral J=?0.552 cm?1 in 2 . 相似文献