1
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Yang ZX, Liang XW, Lin D, Zheng Q, Huo Y. Heteroatom-Modulated Assembly of Hexalanthanoid-Containing Polyoxometalate-Based Coordination Networks. Inorg Chem 2023; 62:1466-1475. [PMID: 36656113 DOI: 10.1021/acs.inorgchem.2c03561] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Two series of lanthanoid (Ln)-containing polyoxometalates (POMs) {[Ln6(ampH)4(H2O)24-n(ampH2)n(PW11O39)2]·21H2O (Ln = Tb, n = 0 (1), Ln = Er, n = 1 (2)) and K2[Ln6(ampH)4(H2O)22(SiW11O39)2]·23H2O (Ln = Tb (3), Er (4)) (ampH2 = (aminomethyl) phosphonic acid)} have been synthesized with tri-lacunary Keggin-type POMs containing different types of heteroatoms. Compounds 1 and 2 display neutral organic-inorganic hybrid POM molecules containing {Ln6(ampH)4} ({Ln6}) cores sandwiched by two {PW11O39} units. By changing the heteroatoms from PV to SiIV, the extended 2D networks of 3 and 4 were successfully isolated where the adjacent {Ln6} clusters were connected by {SiW11O39} moieties. Luminescence performances and magnetic properties of 1-4 have been systematically surveyed. The solid-state fluorescence spectra of 1-4 display characteristic emissions of Ln components resulting from the 4f-4f transitions, and energy transfer from the POM segments to Ln3+ centers in 1 and 3 has been observed based on the lifetime decay behaviors. Furthermore, all compounds can be utilized as electrocatalysts toward reduction of nitrite with high stability.
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Affiliation(s)
- Zeng-Xi Yang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, P. R. China
| | - Xue-Wei Liang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, P. R. China
| | - Dunmin Lin
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, P. R. China
| | - Qiaoji Zheng
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, P. R. China
| | - Yu Huo
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, P. R. China
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2
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Li Z, Li Y, Chen Y, Wang Q, Jadoon M, Yi X, Duan X, Wang X. Developing Dawson-Type Polyoxometalates Used as Highly Efficient Catalysts for Lignocellulose Transformation. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zonghang Li
- Key Lab of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, P. R. China
| | - Yiming Li
- Key Lab of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, P. R. China
| | - Yuannan Chen
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Qiwen Wang
- Key Lab of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, P. R. China
| | - Mehwish Jadoon
- Key Lab of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, P. R. China
| | - Xiaohu Yi
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Xiaozheng Duan
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Xiaohong Wang
- Key Lab of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun 130024, P. R. China
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3
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Li L, Cao S, Wu Z, Guo R, Xie L, Wang L, Tang Y, Li Q, Luo X, Ma L, Cheng C, Qiu L. Modulating Electron Transfer in Vanadium-Based Artificial Enzymes for Enhanced ROS-Catalysis and Disinfection. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2108646. [PMID: 35181946 DOI: 10.1002/adma.202108646] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 01/12/2022] [Indexed: 02/05/2023]
Abstract
Nanomaterials-based artificial enzymes (AEs) have flourished for more than a decade. However, it is still challenging to further enhance their biocatalytic performances due to the limited strategies to tune the electronic structures of active centers. Here, a new path is reported for the de novo design of the d electrons of active centers by modulating the electron transfer in vanadium-based AEs (VOx -AE) via a unique Zn-O-V bridge for efficient reactive oxygen species (ROS)-catalysis. Benefiting from the electron transfer from Zn to V, the V site in VOx -AE exhibits a lower valence state than that in V2 O5 , which results in charge-filled V-dyz orbital near the Fermi level to interfere with the formation of sigma bonds between the V- d z 2 and O-pz orbitals in H2 O2 . The VOx -AE exhibits a twofold Vmax and threefold turnover number than V2 O5 when catalyzing H2 O2 . Meanwhile, the VOx -AE shows enhanced catalytic eradication of drug-resistant bacteria and achieves comparable wound-treatment indexes to vancomycin. This modulating charge-filling of d electrons provides a new direction for the de novo design of nanomaterials-based AEs and deepens the understanding of ROS-catalysis.
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Affiliation(s)
- Ling Li
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
- Department of Ultrasound Affiliated Hospital of North Sichuan Medical College Nanchong 637000 China
| | - Sujiao Cao
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
| | - Zihe Wu
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
| | - Ruiqian Guo
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
| | - Lan Xie
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
| | - Liyun Wang
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
| | - Yuanjiao Tang
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
| | - Qi Li
- The First Affiliated Hospital of Hainan Medical University Hainan 570102 China
| | - Xianglin Luo
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
| | - Lang Ma
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
| | - Chong Cheng
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
- State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu 610065 China
| | - Li Qiu
- Department of Ultrasound College of Polymer Science and Engineering National Clinical Research Center for Geriatrics Med‐X Center for Materials West China Hospital Sichuan University Chengdu 610041 China
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4
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Schreiber E, Brennessel WW, Matson EM. Charge-State Dependence of Proton Uptake in Polyoxovanadate-alkoxide Clusters. Inorg Chem 2022; 61:4789-4800. [PMID: 35293218 PMCID: PMC8965876 DOI: 10.1021/acs.inorgchem.1c02937] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Here, we present
an investigation of the thermochemistry of proton
uptake in acetonitrile across three charge states of a polyoxovanadate-alkoxide
(POV-alkoxide) cluster, [V6O7(OMe)12]n (n = 2–, 1–,
and 0). The vanadium oxide assembly studied features bridging sites
saturated by methoxide ligands, isolating protonation to terminal
vanadyl moieties. Exposure of [V6O7(OMe)12]n to organic acids of appropriate
strength results in the protonation of a terminal V=O bond,
generating the transient hydroxide-substituted POV-alkoxide cluster
[V6O6(OH)(OMe)12]n+1. Evidence for this intermediate proved elusive in our initial
report, but here we present the isolation of a divalent anionic cluster
that features hydrogen bonding to dimethylammonium at the terminal
oxo site. Degradation of the protonated species results in the formation
of equimolar quantities of one-electron-oxidized and oxygen-atom-efficient
complexes, [V6O7(OMe)12]n+1 and [V6O6(OMe)12]n+1. While analogous reactivity was
observed across the three charge states of the cluster, a dependence
on the acid strength was observed, suggesting that the oxidation state
of the vanadium oxide assembly influences the basicity of the cluster
surface. Spectroscopic investigations reveal sigmoidal relationships
between the acid strength and cluster conversion across the redox
series, allowing for determination of the proton affinity of the surface
of the cluster in all three charge states. The fully reduced cluster
is found to be the most basic, with higher oxidation states of the
assembly possessing substantially reduced proton affinities (∼7
pKa units per electron). These results
further our understanding of the site-specific reactivity of terminal M=O bonds with protons in an organic solvent,
revealing design criteria for engineering functional surfaces of metal
oxide materials of relevance to energy storage and conversion. Experimental determination of the surface
basicity of polyoxovanadate-alkoxide
clusters across three oxidation states reveals a charge-state dependence
of proton uptake in molecular, organofunctionalized vanadium oxide
assemblies.
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Affiliation(s)
- Eric Schreiber
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - William W Brennessel
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Ellen M Matson
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
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5
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Fertig AA, Brennessel WW, McKone JR, Matson EM. Concerted Multiproton-Multielectron Transfer for the Reduction of O 2 to H 2O with a Polyoxovanadate Cluster. J Am Chem Soc 2021; 143:15756-15768. [PMID: 34528799 DOI: 10.1021/jacs.1c07076] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The concerted transfer of protons and electrons enables the activation of small-molecule substrates by bypassing energetically costly intermediates. Here, we present the synthesis and characterization of several hydrogenated forms of an organofunctionalized vanadium oxide assembly, [V6O13(TRIOLNO2)2]2-, and their ability to facilitate the concerted transfer of protons and electrons to O2. Electrochemical analysis reveals that the fully reduced cluster is capable of mediating 2e-/2H+ transfer reactions from surface hydroxide ligands, with an average bond dissociation free energy (BDFE) of 61.6 kcal/mol. Complementary stoichiometric experiments with hydrogen-atom-accepting reagents of established bond strengths confirm that the electrochemically established BDFE predicts the 2H+/2e- transfer reactivity of the assembly. Finally, the reactivity of the reduced polyoxovanadate toward O2 reduction is summarized; our results indicate a stepwise reduction of the substrate, proceeding through H2O2 en route to the formation of H2O. Kinetic isotope effect experiments confirm the participation of hydrogen transfer in the rate-determining step of both the reduction of O2 and H2O2. This work constitutes the first example of hydrogen atom transfer for small-molecule activation with reduced polyoxometalates, where both electron and proton originate from the cluster.
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Affiliation(s)
- Alex A Fertig
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - William W Brennessel
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - James R McKone
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Ellen M Matson
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
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6
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Fertig AA, Rabbani SMG, Koch MD, Brennessel WW, Miró P, Matson EM. Physicochemical implications of surface alkylation of high-valent, Lindqvist-type polyoxovanadate-alkoxide clusters. NANOSCALE 2021; 13:6162-6173. [PMID: 33734254 DOI: 10.1039/d0nr09201k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report a rare example of the direct alkylation of the surface of a plenary polyoxometalate cluster by leveraging the increased nucleophilicity of vanadium oxide assemblies. Addition of methyl trifluoromethylsulfonate (MeOTf) to the parent polyoxovanadate cluster, [V6O13(TRIOLR)2]2- (TRIOL = tris(hydroxymethyl)methane; R = Me, NO2) results in functionalisation of one or two bridging oxide ligands of the cluster core to generate [V6O12(OMe)(TRIOLR)2]1- and [V6O11(OMe)2(TRIOLR)2]2-, respectively. Comparison of the electronic absorption spectra of the functionalised and unfunctionalised derivatives indicates the decreased overall charge of the complex results in a decrease in the energy required for ligand to metal charge transfer events to occur, while simultaneously mitigating the inductive effects imposed by the capping TRIOL ligand. Electrochemical analysis of the family of organofunctionalised polyoxovanadate clusters reveals the relationship of ligand environment and the redox properties of the cluster core: increased organofunctionalisation of the surface of the vanadium oxide assembly translates to anodic shifts in the reduction events of the Lindqvist ion. Overall, this work provides insight into the electronic effects induced upon atomically precise modifications to the surface structure of nanoscopic, redox-active metal oxide assemblies.
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Affiliation(s)
- Alex A Fertig
- Department of Chemistry, University of Rochester, Rochester, NY 14627, USA.
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7
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Minato T, Aravena D, Ruiz E, Yamaguchi K, Mizuno N, Suzuki K. Effect of Heteroatoms on Field-Induced Slow Magnetic Relaxation of Mononuclear FeIII (S = 5/2) Ions within Polyoxometalates. Inorg Chem 2018; 57:6957-6964. [DOI: 10.1021/acs.inorgchem.8b00644] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takuo Minato
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Daniel Aravena
- Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla
40, Correo 33, Santiago, Chile
| | - Eliseo Ruiz
- Departament de Química Inorgànica i Orgànica and Institut de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Kazuya Yamaguchi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Noritaka Mizuno
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kosuke Suzuki
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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8
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Zheng Q, Vilà-Nadal L, Lang Z, Chen JJ, Long DL, Mathieson JS, Poblet JM, Cronin L. Self-Sorting of Heteroanions in the Assembly of Cross-Shaped Polyoxometalate Clusters. J Am Chem Soc 2018; 140:2595-2601. [PMID: 29359931 PMCID: PMC6075695 DOI: 10.1021/jacs.7b11982] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Heteroanion (HA) moieties have a key role in templating of heteropolyoxometalate (HPA) architectures, but clusters templated by two different templates are rarely reported. Herein, we show how a cross-shaped HPA-based architecture can self-sort the HA templates by pairing two different guests into a divacant {XYW15O54} building block, with four of these building block units being linked together to complete the cross-shaped architecture. We exploited this observation to incorporate HA templates into well-defined positions within the clusters, leading to the isolation of a collection of mixed-HA templated cross-shaped polyanions [(XYW15O54)4(WO2)4]32-/36- (X = H-P, Y = Se, Te, As). The template positions have been unambiguously determined by single crystal X-ray diffraction, NMR spectroscopy, and high-resolution electrospray ionization mass spectrometry; these studies demonstrated that the mixed template containing HPA clusters are the preferred products which crystallize from the solution. Theoretical studies using DFT calculations suggest that the selective self-sorting originates from the coordination of the template in solution. The cross-shaped polyoxometalate clusters are redox-active, and the ability of molecules to accept electrons is slightly modulated by the HA incorporated as shown by differential pulse voltammetry experiments. These results indicate that the cross-shaped HPAs can be used to select templates from solution, and themselves have interesting geometries, which will be useful in developing functional molecular architectures based upon HPAs with well-defined structures and electronic properties.
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Affiliation(s)
- Qi Zheng
- WestCHEM, School of Chemistry, The University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - Laia Vilà-Nadal
- WestCHEM, School of Chemistry, The University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - Zhongling Lang
- Departament de Química Física i Inorgànica, Universitat Rovira i Virgili , c/Marcel·lí Domingo 1, 43007 Tarragona, Spain
| | - Jia-Jia Chen
- WestCHEM, School of Chemistry, The University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - De-Liang Long
- WestCHEM, School of Chemistry, The University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - Jennifer S Mathieson
- WestCHEM, School of Chemistry, The University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - Josep M Poblet
- Departament de Química Física i Inorgànica, Universitat Rovira i Virgili , c/Marcel·lí Domingo 1, 43007 Tarragona, Spain
| | - Leroy Cronin
- WestCHEM, School of Chemistry, The University of Glasgow , Glasgow G12 8QQ, United Kingdom
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9
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Liu CG, Zheng T, Liu S, Zhang HY. Photodegradation of malachite green dye catalyzed by Keggin-type polyoxometalates under visible-light irradiation: Transition metal substituted effects. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2016.01.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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10
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Gunaratne KDD, Prabhakaran V, Andersen A, Johnson GE, Laskin J. Charge retention of soft-landed phosphotungstate Keggin anions on self-assembled monolayers. Phys Chem Chem Phys 2016; 18:9021-8. [DOI: 10.1039/c5cp06954h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Preferential immobilization of the 2− charge state observed for polyoxotungstate Keggin anions soft-landed onto self-assembled monolayer surfaces.
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Affiliation(s)
| | | | - Amity Andersen
- Pacific Northwest National Laboratory
- Physical Sciences Division
- Richland
- USA
| | - Grant E. Johnson
- Pacific Northwest National Laboratory
- Physical Sciences Division
- Richland
- USA
| | - Julia Laskin
- Pacific Northwest National Laboratory
- Physical Sciences Division
- Richland
- USA
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11
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Gunaratne KDD, Prabhakaran V, Johnson GE, Laskin J. Gas-Phase Fragmentation Pathways of Mixed Addenda Keggin Anions: PMo12-nW nO 40 3- (n = 0-12). JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:1027-1035. [PMID: 25832027 DOI: 10.1007/s13361-015-1090-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/28/2015] [Accepted: 01/28/2015] [Indexed: 06/04/2023]
Abstract
We report a collision-induced dissociation (CID) investigation of the mixed addenda polyoxometalate (POM) anions, PMo(12-n)W(n)O(40)(3-) (n = 0-12). The anions were generated in solution using a straightforward single-step synthesis approach and introduced into the gas phase by electrospray ionization (ESI). Distinct differences in fragmentation patterns were observed for the range of mixed addenda POMs examined in this study. CID of molybdenum-rich anions, PMo(12-n)W(n)O(40)(3-) (n = 0-2), generates an abundant doubly charged fragment containing seven metal atoms (M) and 22 oxygen atoms (M(7)O(22)(2-)) and its complementary singly charged PM(5)O(18)(-) ion. In comparison, the doubly charged Lindqvist anion, (M(6)O(19)(2-)) and its complementary singly charged PM(6)O(21)(-) ion are the dominant fragments of Keggin POMs containing more than two tungsten atoms, PMo(12-n)W(n)O(40)(3-) (n = 3-12). The observed transition in the dissociation pathways with an increase in the number of W atoms in the POM may be attributed to the higher barrier of tungsten-rich anions towards isomerization. We present evidence that the observed distribution of Mo and W atoms in the major M(6)O(19)(2-) and M(7)O(22)(2-) fragment ions is different from that predicted by a random distribution, indicating substantial segregation of the addenda metal atoms in the POMs. Charge reduction of the triply charged precursor anion resulting in formation of doubly charged anions is also observed. This is a dominant pathway for mixed POMs having a majority (8-11) of W atoms and a minor channel for other precursors indicating a close competition between fragmentation and charge loss pathways in CID of POM anions.
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Affiliation(s)
- K Don D Gunaratne
- Physical Sciences Division, Pacific Northwest National Laboratory, MSIN K8-88, P.O. Box 999, Richland, WA, 99352, USA
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12
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Uehara K, Miyachi T, Mizuno N. Amphiprotic properties of a bis(μ-hydroxo)divanadium(IV)-substituted γ-Keggin-type silicodecatungstate containing two different kinds of hydroxyl moieties. Inorg Chem 2014; 53:5341-7. [PMID: 24807303 DOI: 10.1021/ic500642v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A bis(μ-hydroxo)divanadium(IV)-substituted γ-Keggin-type silicodecatungstate, (TBA)4[γ-SiV(IV)2W10O36(μ-OH)4] (1), possesses two different kinds of hydroxyl groups and can work as an amphiprotic species to accept and donate proton(s). Dehydrative condensation reactions of 1 with methanol and formic acid proceed on more basic hydroxyl groups between two vanadium atoms without the deprotonation of more acidic hydroxides between two tungsten atoms to form (TBA)4[γ-SiV(IV)2W10O36(μ-OH)3(μ-OR)] (2·R, R = Me, Et, Pr; 3, R = C(O)H), showing Brønsted base properties of the hydroxyl groups between two vanadium atoms. On the other hand, the hydroxyl groups between tungsten atoms exhibit Brønsted acid properties and react with pyridine (Py) and TBAOH to form (TBA)4X[γ-SiV(IV)2W10O37(μ-OH)3] (PyH·4, X = PyH; TBA·4, X = TBA). DFT calculations for [γ-SiV(IV)2W10O36(μ-OH)4](4-) in water also support both the acidic and basic nature of hydroxyl groups in 1.
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Affiliation(s)
- Kazuhiro Uehara
- Department of Applied Chemistry, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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