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Borunda T, Myers AJ, Mary Fisher J, Crans DC, Johnson MD. Confinement Effects on Chemical Equilibria: Pentacyano(Pyrazine)Ferrate(II) Stability Changes within Nanosized Droplets of Water. Molecules 2018; 23:E858. [PMID: 29642558 PMCID: PMC6016957 DOI: 10.3390/molecules23040858] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 03/30/2018] [Accepted: 04/04/2018] [Indexed: 11/16/2022] Open
Abstract
Nanoscale confinement is known to impact properties of molecules and we observed changes in the reactivity of an iron coordination complex, pentacyano(pyrazine)ferrate(II). The confinement of two coordination complexes in a sodium AOT/isooctane reverse micellar (RM) water droplet was found to dramatically increase the hydrolysis rate of [Fe(CN)₅pyz]3- and change the monomer-dimer equilibria between [Fe(CN)₅pyz]3- and [Fe₂(CN)10pyz]6-. Combined UV-Vis and ¹H-NMR spectra of these complexes in RMs were analyzed and the position of the monomer-dimer equilibrium and the relative reaction times were determined at three different RM sizes. The data show that the hydrolysis rates (loss of pyrazine) are dramatically enhanced in RMs over bulk water and increase as the size of the RM decreases. Likewise, the monomer-dimer equilibrium changes to favor the formation of dimer as the RM size decreases. We conclude that the effects of the [Fe(CN)₅pyz]3- stability is related to its solvation within the RM.
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Affiliation(s)
- Teofilo Borunda
- Department of Chemistry & Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA.
| | - Alexander J Myers
- Department of Chemistry & Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA.
| | - J Mary Fisher
- Department of Chemistry, Colorado State University, Ft. Collins, CO 80523, USA.
| | - Debbie C Crans
- Department of Chemistry, Colorado State University, Ft. Collins, CO 80523, USA.
| | - Michael D Johnson
- Department of Chemistry & Biochemistry, New Mexico State University, Las Cruces, NM 88003, USA.
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Yan JA, Chen YS, Chang YH, Tsai CY, Lyu CL, Luo CG, Lee GH, Hsu HF. Redox Interconversion of Non-Oxido Vanadium Complexes Accompanied by Acid–Base Chemistry of Thiol and Thiolate. Inorg Chem 2017; 56:9055-9063. [DOI: 10.1021/acs.inorgchem.7b01040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jyun-An Yan
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Yu-Sen Chen
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Ya-Ho Chang
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Cheng-Yun Tsai
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Chiao-Ling Lyu
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Chun-Gang Luo
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Gene-Hsiang Lee
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Hua-Fen Hsu
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
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3
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Gupta R, Huang W, Francesconi LC, Polenova T. Effect of positional isomerism and vanadium substitution on 51V magic angle spinning NMR Spectra Of Wells-Dawson polyoxotungstates. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2017; 84:28-33. [PMID: 27998683 PMCID: PMC5466850 DOI: 10.1016/j.ssnmr.2016.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 12/02/2016] [Accepted: 12/04/2016] [Indexed: 06/06/2023]
Abstract
We examined the positional isomerism and vanadium substitution on the 51V magic angle spinning NMR spectra of potassium salts of vanadium-substituted polyoxotungstates of the Wells-Dawson series. NMR parameters of this class of catalytically active polyoxotungstates effect of are reported. Multiple species, indicative of differences in the local environment at the substitution sites, are observed in solid-state NMR spectra of the di- and tri- substituted complexes in contrast to solution NMR spectra, where single average chemical shift was observed. The quadrupolar and chemical shift anisotropy parameters depend strongly on the position and the degree of the vanadium substitution into the oxoanion core establishing 51V SATRAS NMR spectroscopy as a sensitive probe of the local electronic environment in these catalytically active solids.
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Affiliation(s)
- Rupal Gupta
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Wenlin Huang
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Lynn C Francesconi
- Department of Chemistry, City University of New York, Hunter College, 695 Park Avenue, New York 10021, USA; Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York 10016, USA.
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA.
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Dragancea D, Talmaci N, Shova S, Novitchi G, Darvasiová D, Rapta P, Breza M, Galanski M, Kožı́šek J, Martins NMR, Martins LMDRS, Pombeiro AJL, Arion VB. Vanadium(V) Complexes with Substituted 1,5-bis(2-hydroxybenzaldehyde)carbohydrazones and Their Use As Catalyst Precursors in Oxidation of Cyclohexane. Inorg Chem 2016; 55:9187-203. [DOI: 10.1021/acs.inorgchem.6b01011] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Diana Dragancea
- Institute of Chemistry, Academy of Sciences of Moldova, Academiei Str. 3, MD-2028 Chisinau, Moldova
| | - Natalia Talmaci
- Institute of Chemistry, Academy of Sciences of Moldova, Academiei Str. 3, MD-2028 Chisinau, Moldova
| | - Sergiu Shova
- “Petru Poni” Institute
of Macromolecular Chemistry, Aleea
Gr. Ghica Voda 41A, 700487 Iasi, Romania
| | - Ghenadie Novitchi
- Laboratoire National
des Champs Magnetiques Intenses-CNRS, Universite Joseph Fourier, 25 Avenue
des Martyrs, 38042 Grenoble Cedex 9, France
| | - Denisa Darvasiová
- Institute of Physical Chemistry
and Chemical Physics, Slovak University of Technology, Radlinského
9, 81237 Bratislava, Slovakia
| | - Peter Rapta
- Institute of Physical Chemistry
and Chemical Physics, Slovak University of Technology, Radlinského
9, 81237 Bratislava, Slovakia
| | - Martin Breza
- Institute of Physical Chemistry
and Chemical Physics, Slovak University of Technology, Radlinského
9, 81237 Bratislava, Slovakia
| | - Markus Galanski
- Institute of Inorganic Chemistry, University of Vienna, Währinger
Strasse 42, A-1090 Vienna, Austria
| | - Jozef Kožı́šek
- Institute of Physical Chemistry
and Chemical Physics, Slovak University of Technology, Radlinského
9, 81237 Bratislava, Slovakia
| | - Nuno M. R. Martins
- Centro de Química Estrutural, Complexo
I, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco
Pais, 1049-001 Lisboa, Portugal
| | - Luísa M. D. R. S. Martins
- Centro de Química Estrutural, Complexo
I, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco
Pais, 1049-001 Lisboa, Portugal
- Chemical Engineering Department, Instituto
Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, R. Conselheiro Emídio Navarro, 1959-007 Lisboa, Portugal
| | - Armando J. L. Pombeiro
- Centro de Química Estrutural, Complexo
I, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco
Pais, 1049-001 Lisboa, Portugal
| | - Vladimir B. Arion
- Institute of Inorganic Chemistry, University of Vienna, Währinger
Strasse 42, A-1090 Vienna, Austria
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5
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Gupta R, Yehl J, Li M, Polenova T. 51V magic angle spinning NMR spectroscopy and quantum chemical calculations in vanadium bio-inorganic systems: current perspective. CAN J CHEM 2015. [DOI: 10.1139/cjc-2014-0557] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In recent years, 51V magic angle spinning (MAS) NMR spectroscopy has been widely used to characterize vanadium centers in biology, biomimetic complexes, and inorganic compounds of medicinal and industrial relevance. It has been demonstrated that 51V NMR parameters are sensitive probes of the coordination geometry and chemical environment of the metal center, beyond the first coordination sphere. To establish the relationships between NMR parameters and structure of the vanadium centers, over the past decade a large series of coordination complexes have been analyzed by MAS NMR spectroscopy. It has been demonstrated that the interpretation of the NMR parameters requires the use of theoretical methods, such as density functional (DFT) theory, whereby the experimental NMR observables are linked to the electronic and structural properties of a molecule. DFT calculations have been successfully employed to not only predict NMR parameters but to also yield valuable information regarding the structure and function of various vanadium compounds. In this report, we review the current state of the field, and present a survey of bioinorganic vanadium complexes as well as vanadium-dependent haloperoxidases analyzed using 51V MAS NMR spectroscopy and DFT calculations, to illustrate the rich information content available from such a combined approach.
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Affiliation(s)
- Rupal Gupta
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Jenna Yehl
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Mingyue Li
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
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Goncharova-Zapata O, Chatterjee PB, Hou G, Quinn LL, Li M, Yehl J, Crans DC, Polenova T. Effect of Ancillary Ligand on Electronic Structure as Probed by 51V Solid-State NMR Spectroscopy for Vanadium- o-Dioxolene Complexes. CrystEngComm 2013; 15. [PMID: 24353476 DOI: 10.1039/c3ce41322e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A series of vanadium(V) complexes with o-dioxolene (catecholato) ligands and an ancillary ligand, (N-(salicylideneaminato)ethylenediamine) (hensal), were investigated using 51V solid-state magic angle spinning NMR spectroscopy (51V MAS NMR) to assess the local environment of the vanadium(V). The solid-state 51V NMR parameters of vanadium(V) complexes with a related potentially tetradentate ancillary ligand (N-salicylidene-N'-(2-hydroxyethyl)ethylenediamine) (h2shed) were previously shown to be associated with the size of the HOMO-LUMO gap in the complex, and as such provide insights on the interaction between metal ion and ligand (P. B. Chatterjee, et al., Inorg. Chem 50 (2011) 9794). Our results show that the modification of the ancillary ligand does not impact the observed trend between complexes ranging from catechols with electron rich to electron poor substituents. However, the ancillary ligand does impact the size of the HOMO-LUMO separation in the parent complex and thus the solid-state vanadium NMR chemical shift of the unsubstituted vanadium complex. For these complexes significant changes observed in the isotropic shifts and more modest changes detected in the CQ reflect the electronic changes in the complex as the catechol is varied. However, no obvious trend was observed in the chemical shift anisotropies (δσ and ησ) with the variation in the catechol. The electronic changes in the coordination environment of the vanadium can be described using solid-state 51V NMR spectroscopy.
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Affiliation(s)
- Olga Goncharova-Zapata
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968
| | - Pabitra B Chatterjee
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA. Tel. +1-970-491-7635
| | - Guangjin Hou
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968
| | - Laurence L Quinn
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968
| | - Mingyue Li
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968
| | - Jenna Yehl
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968
| | - Debbie C Crans
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA. ; Tel. +1-302-831-1968
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Chatterjee PB, Goncharov-Zapata O, Quinn LL, Hou G, Hamaed H, Schurko RW, Polenova T, Crans DC. Characterization of noninnocent metal complexes using solid-state NMR spectroscopy: o-dioxolene vanadium complexes. Inorg Chem 2011; 50:9794-803. [PMID: 21842875 DOI: 10.1021/ic200046k] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
(51)V solid-state NMR (SSNMR) studies of a series of noninnocent vanadium(V) catechol complexes have been conducted to evaluate the possibility that (51)V NMR observables, quadrupolar and chemical shift anisotropies, and electronic structures of such compounds can be used to characterize these compounds. The vanadium(V) catechol complexes described in these studies have relatively small quadrupolar coupling constants, which cover a surprisingly small range from 3.4 to 4.2 MHz. On the other hand, isotropic (51)V NMR chemical shifts cover a wide range from -200 to 400 ppm in solution and from -219 to 530 ppm in the solid state. A linear correlation of (51)V NMR isotropic solution and solid-state chemical shifts of complexes containing noninnocent ligands is observed. These experimental results provide the information needed for the application of (51)V SSNMR spectroscopy in characterizing the electronic properties of a wide variety of vanadium-containing systems and, in particular, those containing noninnocent ligands and that have chemical shifts outside the populated range of -300 to -700 ppm. The studies presented in this report demonstrate that the small quadrupolar couplings covering a narrow range of values reflect the symmetric electronic charge distribution, which is also similar across these complexes. These quadrupolar interaction parameters alone are not sufficient to capture the rich electronic structure of these complexes. In contrast, the chemical shift anisotropy tensor elements accessible from (51)V SSNMR experiments are a highly sensitive probe of subtle differences in electronic distribution and orbital occupancy in these compounds. Quantum chemical (density functional theory) calculations of NMR parameters for [VO(hshed)(Cat)] yield a (51)V chemical shift anisotropy tensor in reasonable agreement with the experimental results, but surprisingly the calculated quadrupolar coupling constant is significantly greater than the experimental value. The studies demonstrate that substitution of the catechol ligand with electron-donating groups results in an increase in the HOMO-LUMO gap and can be directly followed by an upfield shift for the vanadium catechol complex. In contrast, substitution of the catechol ligand with electron-withdrawing groups results in a decrease in the HOMO-LUMO gap and can directly be followed by a downfield shift for the complex. The vanadium catechol complexes were used in this work because (51)V is a half-integer quadrupolar nucleus whose NMR observables are highly sensitive to the local environment. However, the results are general and could be extended to other redox-active complexes that exhibit coordination chemistry similar to that of the vanadium catechol complexes.
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Affiliation(s)
- Pabitra B Chatterjee
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA
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