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Title: Bi-antimony capped Keggin polyoxometalate modified with Cu-ligand fragment

Abstract

Three polyoxometalates consisting of bi-antimony capped Keggin-type clusters: [Cu(mbpy){sub 2}]{sub 2}[PMo{sub 12}O{sub 40}Sb{sub 2}]{center_dot}4H{sub 2}O (1), [Cu(mbpy){sub 2}][PMo{sub 12}O{sub 40}Sb{sub 2}] (2) and {l_brace}Cu(mbpy)[Cu(mbpy){sub 2}]{sub 2}{r_brace}[VMo{sub 8}V{sub 4}O{sub 40}Sb{sub 2}]{center_dot}2H{sub 2}O (3) (mbpy=4,4 Prime -dimethyl-2,2 Prime - dipyridyl in 1 and 2; 5,5 Prime -dimethyl-2,2 Prime -dipyridyl in 3) have been synthesized and characterized by IR, X-ray powder diffraction, TG analysis and electrochemical property. Single-crystal analysis revealed that all of three compounds are built upon bi-antimony capped Keggin-type polyoxoanions and Cu-mbpy cations. In 1-3, two Sb{sup III} centers located at the two opposite of anionic surface adopt fundamentally tetragonal pyramidal coordination geometry. Both compounds 1 and 2 consist of P-centered Keggin structure, while compound 3 presents a V-centered Keggin anion. The Keggin-type anions present different structural features: isolated cluster in 1 and Cu-ligand-supported cluster in 2 and 3. - Graphical abstract: Three hybrid compounds consisting of bi-antimony capped Keggin-type clusters modified with Cu-ligand cations have been synthesized and characterized. Highlights: Black-Right-Pointing-Pointer Three hybrid compounds consisting of bi-antimony capped Keggin-type clusters have been synthesized. Black-Right-Pointing-Pointer Two Sb{sup III} centers located at the two opposite of anionic surface adopt tetragonal pyramidal coordination geometry. Black-Right-Pointing-Pointer The anions present different structural features: isolated andmore » Cu-ligand-supported cluster.« less

Authors:
 [1];  [1]; ;  [1];  [1]
  1. College of Chemistry and Material Science, Hebei Normal University, No. 20 Road East of 2nd Ring South, Yuhua District, Shijiazhuang, Hebei 050024 (China)
Publication Date:
OSTI Identifier:
22149829
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 194; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ANIONS; ANTIMONY; CATIONS; CRYSTAL STRUCTURE; LIGANDS; MONOCRYSTALS; SURFACES; THERMAL GRAVIMETRIC ANALYSIS; X-RAY DIFFRACTION

Citation Formats

Huang, Jiao, Han, Zhangang, E-mail: hanzg116@yahoo.com.cn, Zhang, Heng, Yu, Haitao, and Zhai, Xueliang, E-mail: xlzhai253@mail.hebtu.edu.cn. Bi-antimony capped Keggin polyoxometalate modified with Cu-ligand fragment. United States: N. p., 2012. Web. doi:10.1016/J.JSSC.2012.07.040.
Huang, Jiao, Han, Zhangang, E-mail: hanzg116@yahoo.com.cn, Zhang, Heng, Yu, Haitao, & Zhai, Xueliang, E-mail: xlzhai253@mail.hebtu.edu.cn. Bi-antimony capped Keggin polyoxometalate modified with Cu-ligand fragment. United States. doi:10.1016/J.JSSC.2012.07.040.
Huang, Jiao, Han, Zhangang, E-mail: hanzg116@yahoo.com.cn, Zhang, Heng, Yu, Haitao, and Zhai, Xueliang, E-mail: xlzhai253@mail.hebtu.edu.cn. 2012. "Bi-antimony capped Keggin polyoxometalate modified with Cu-ligand fragment". United States. doi:10.1016/J.JSSC.2012.07.040.
@article{osti_22149829,
title = {Bi-antimony capped Keggin polyoxometalate modified with Cu-ligand fragment},
author = {Huang, Jiao and Han, Zhangang, E-mail: hanzg116@yahoo.com.cn and Zhang, Heng and Yu, Haitao and Zhai, Xueliang, E-mail: xlzhai253@mail.hebtu.edu.cn},
abstractNote = {Three polyoxometalates consisting of bi-antimony capped Keggin-type clusters: [Cu(mbpy){sub 2}]{sub 2}[PMo{sub 12}O{sub 40}Sb{sub 2}]{center_dot}4H{sub 2}O (1), [Cu(mbpy){sub 2}][PMo{sub 12}O{sub 40}Sb{sub 2}] (2) and {l_brace}Cu(mbpy)[Cu(mbpy){sub 2}]{sub 2}{r_brace}[VMo{sub 8}V{sub 4}O{sub 40}Sb{sub 2}]{center_dot}2H{sub 2}O (3) (mbpy=4,4 Prime -dimethyl-2,2 Prime - dipyridyl in 1 and 2; 5,5 Prime -dimethyl-2,2 Prime -dipyridyl in 3) have been synthesized and characterized by IR, X-ray powder diffraction, TG analysis and electrochemical property. Single-crystal analysis revealed that all of three compounds are built upon bi-antimony capped Keggin-type polyoxoanions and Cu-mbpy cations. In 1-3, two Sb{sup III} centers located at the two opposite of anionic surface adopt fundamentally tetragonal pyramidal coordination geometry. Both compounds 1 and 2 consist of P-centered Keggin structure, while compound 3 presents a V-centered Keggin anion. The Keggin-type anions present different structural features: isolated cluster in 1 and Cu-ligand-supported cluster in 2 and 3. - Graphical abstract: Three hybrid compounds consisting of bi-antimony capped Keggin-type clusters modified with Cu-ligand cations have been synthesized and characterized. Highlights: Black-Right-Pointing-Pointer Three hybrid compounds consisting of bi-antimony capped Keggin-type clusters have been synthesized. Black-Right-Pointing-Pointer Two Sb{sup III} centers located at the two opposite of anionic surface adopt tetragonal pyramidal coordination geometry. Black-Right-Pointing-Pointer The anions present different structural features: isolated and Cu-ligand-supported cluster.},
doi = {10.1016/J.JSSC.2012.07.040},
journal = {Journal of Solid State Chemistry},
number = ,
volume = 194,
place = {United States},
year = 2012,
month =
}
  • Two new supramolecular polyoxometalate compounds [Ag{sub 2}(mbpy){sub 3}][Ag(mbpy){sub 2}][PW{sub 12}O{sub 40}] (1) and [Ag{sub 2}(mbpy){sub 3}]{sub 2}[SiW{sub 12}O{sub 40}] (2) (mbpy=4,4'-dimethyl-2,2'-dipyridyl), have been hydrothermally synthesized and characterized by IR, TG, and single-crystal X-ray diffraction techniques. The structural feature of 1–2 is in the cationic moiety of a tetra-core (Ag{sub 4}) cluster through weak Ag…Ag interactions. The silver(I) centers show three-, four- and five-coordinated geometries. In 1 the tetrameric silver atoms in ([Ag{sub 2}(mbpy){sub 3}]{sub 2}){sup 4+} covalently bind to [PW{sub 12}O{sub 40}]{sup 3−} anion via Ag3O bonds, while there is only intermolecular hydrogen bonding between ([Ag{sub 2}(mbpy){sub 3}]{sub 2}){sup 4+}more » and [SiW{sub 12}O{sub 40}]{sup 4−} in 2. The coordination environments of the tetrameric silver cations have a great influence on the structure richness of the Keggin-based hybrids. The fluorescence properties of compounds 1 and 2 also have been discussed. - Graphical abstract: New polyoxometalate-based hybrids consisting of Keggin-type clusters modified by (Ag{sub 4}) groups had been synthesized and characterized, and their photoluminescence properties were also discussed. Display Omitted - Highlights: • Two Keggin-type polyoxometalates consisting of (Ag{sub 4}) clusters through weak Ag…Ag interactions have been synthesized. • There exist face-to-face and dot-to-face π…π interactions in (Ag-ligand){sub 4} fragment. • The fluorescence properties of (Ag{sub 4}) modified POMs are also discussed.« less
  • The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. Reliable correlations among structure, composition, and function in heterogeneous catalysis require well-defined atomic connectivity within active structures and the assessment of the specific elementary steps and reaction intermediates responsible for the relevant catalytic function. The non-uniform nature of typical active structures creates significant challenges because probes of structure and function average such heterogeneity in complex ways. Polyoxometalate (POM) clusters withmore » stable Keggin structures and well-defined atomic connectivity provide the compositional diversity required for a rigorous assessment of the consequences of composition on catalytic reactivity.« less
  • The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. The kinetics and mechanism of ether and alkanol cleavage reactions on Brønsted acid catalysts based on polyoxometalate (POM) clusters are described in terms of the identity and dynamics of elementary steps and the stability of the transition states involved. Measured rates and theoretical calculations show that the energies of cationic transition states and intermediates depend on the properties of reactantsmore » (proton affinity), POM clusters (deprotonation enthalpy), and ion-pairs in transition states or intermediates (stabilization energy). Rate equations and elementary steps were similar for dehydration of alkanols (2- propanol, 1- and 2-butanol, tert-butanol) and cleavage of sec-butyl-methyl ether on POM clusters with different central atoms (P, Si, Co, Al). Dehydration rates depend on the rate constant for elimination from adsorbed alkanols or ethers and on the equilibrium constant for the formation of unreactive reactant dimers. Elimination involves E1 pathways and late carbenium-ion transition states. This is consistent with small kinetic isotope effects for all deuterated alkanols, with strong effects of substituents on elimination rates, and with the similar alkene stereoselectivities measured for alkanol dehydration, ether cleavage, and alkene double-bond isomerization. n-Donor reactants (alkanols, ethers) and products (water) inhibit dehydration rates by forming stable dimers that do not undergo elimination; their stability is consistent with theoretical estimates, with the dynamics of homogeneous analogues, and with the structure and proton affinity of the n-donors. Elimination rate constants increased with increasing valence of the central POM atom, because of a concurrent decrease in deprotonation enthalpies (DPE), which leads to more stable anionic clusters and ion-pairs at transition states. The DPE of POM clusters influences catalytic rates less than the proton affinity of the alkene-like organic moiety at the late carbenium-ion-type transition states involved. These different sensitivities reflect the fact that weaker acids typically form anionic clusters with a higher charge density at the transition state; these clusters stabilize cationic fragments more effectively than those of stronger acids, which form more stable conjugate bases with lower charge densities. These compensation effects are ubiquitous in acid chemistry and also evident for mineral acids. The stabilization energy and the concomitant charge density and distribution in the anion, but not the acid strength (DPE), determine the kinetic tolerance of n-donors and the selectivity of reactions catalyzed by Brønsted acids.« less
  • Two new neutral bicapped bisupporting Keggin-polyoxometalate derivatives: [M(2,2'-bpy){sub 2}(H{sub 2}O)]{sub 2}[SiMo{sup VI}{sub 8}Mo{sup V}{sub 4}V{sup IV}{sub 2}O{sub 42}] (M=Co 1, Zn 2; 2,2'-bpy=2,2'-bipyridine), have been synthesized under hydrothermal conditions by directly using H{sub 4}SiMo{sub 12}O{sub 40} as starting materials. Crystal data for compound 1: C{sub 40}H{sub 36}Co{sub 2}Mo{sub 12}N{sub 8}O{sub 44}SiV{sub 2}, triclinic, space group P1-bar , a=11.884(2)A, b=12.459(3)A, c=12.652(3)A, {alpha}=71.02(3){sup o}, {beta}=74.51(3){sup o}, {gamma}=86.74(3){sup o}, V=1706.3(6)A{sup 3}, Z=1; for compound 2, C{sub 40}H{sub 36}Mo{sub 12}N{sub 8}O{sub 44}SiV{sub 2}Zn{sub 2}, triclinic, space group P1-bar , a=11.879(2)A, b=12.469(3)A, c=12.635(3)A, {alpha}=71.28(3){sup o}, {beta}=74.78(3){sup o}, {gamma}=86.60(3){sup o}, V=1709.6(6)A{sup 3}, Z=1. The studies ofmore » the electrochemical property of compounds 1 and 2 exhibit similar redox behavior to the parent [(C{sub 4}H{sub 9}){sub 4}N]{sub 4}SiMo{sub 12}O{sub 40}, undergoing three two-electron reversible reductions. Variable-temperature magnetic susceptibility measurement of compound 1 demonstrates the presence of antiferromagnetic interactions.« less