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Liao CJ, Tseng YT, Cheng YA, Dayao LA, Iffland-Mühlhaus L, Gee LB, Ribson RD, Chan TS, Apfel UP, Lu TT. Ligand Control of Dinitrosyl Iron Complexes for Selective Superoxide-Mediated Nitric Oxide Monooxygenation and Superoxide-Dioxygen Interconversion. J Am Chem Soc 2023; 145:20389-20402. [PMID: 37683125 DOI: 10.1021/jacs.3c05577] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
Through nitrosylation of [Fe-S] proteins, or the chelatable iron pool, a dinitrosyl iron unit (DNIU) [Fe(NO)2] embedded in the form of low-molecular-weight/protein-bound dinitrosyl iron complexes (DNICs) was discovered as a metallocofactor assembled under inflammatory conditions with elevated levels of nitric oxide (NO) and superoxide (O2-). In an attempt to gain biomimetic insights into the unexplored transformations of the DNIU under inflammation, we investigated the reactivity toward O2- by a series of DNICs [(NO)2Fe(μ-MePyr)2Fe(NO)2] (1) and [(NO)2Fe(μ-SEt)2Fe(NO)2] (3). During the superoxide-induced conversion of DNIC 1 into DNIC [(K-18-crown-6-ether)2(NO2)][Fe(μ-MePyr)4(μ-O)2(Fe(NO)2)4] (2-K-crown) and a [Fe3+(MePyr)x(NO2)y(O)z]n adduct, stoichiometric NO monooxygenation yielding NO2- occurs without the transient formation of peroxynitrite-derived •OH/•NO2 species. To study the isoelectronic reaction of O2(g) and one-electron-reduced DNIC 1, a DNIC featuring an electronically localized {Fe(NO)2}9-{Fe(NO)2}10 electronic structure, [K-18-crown-6-ether][(NO)2Fe(μ-MePyr)2Fe(NO)2] (1-red), was successfully synthesized and characterized. Oxygenation of DNIC 1-red leads to the similar assembly of DNIC 2-K-crown, of which the electronic structure is best described as paramagnetic with weak antiferromagnetic coupling among the four S = 1/2 {FeIII(NO-)2}9 units and S = 5/2 Fe3+ center. In contrast to DNICs 1 and 1-red, DNICs 3 and [K-18-crown-6-ether][(NO)2Fe(μ-SEt)2Fe(NO)2] (3-red) display a reversible equilibrium of "3 + O2- ⇋ 3-red + O2(g)", which is ascribed to the covalent [Fe(μ-SEt)2Fe] core and redox-active [Fe(NO)2] unit. Based on this study, the supporting/bridging ligands in dinuclear DNIC 1/3 (or 1-red/3-red) control the selective monooxygenation of NO and redox interconversion between O2- and O2 during reaction with O2- (or O2).
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Affiliation(s)
- Cheng-Jhe Liao
- Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Yu-Ting Tseng
- Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Yu-An Cheng
- Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Loise Ann Dayao
- Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Linda Iffland-Mühlhaus
- Department of Chemistry and Biochemistry, Inorganic Chemistry I, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Leland B Gee
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Ryan D Ribson
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Ting-Shan Chan
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Ulf-Peter Apfel
- Department of Chemistry and Biochemistry, Inorganic Chemistry I, Ruhr-Universität Bochum, 44801 Bochum, Germany
- Department of Electrosynthesis, Fraunhofer UMSICHT, 46047 Oberhausen, Germany
| | - Tsai-Te Lu
- Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Chemistry, Chung Yuan Christian University, Taoyuan 32023, Taiwan
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2
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Lu S, Chiou TW, Li WL, Wang CC, Wang YM, Lee WZ, Lu TT, Liaw WF. Dinitrosyliron Complex [(PMDTA)Fe(NO)2]: Intermediate for Nitric Oxide Monooxygenation Activity in Nonheme Iron Complex. Inorg Chem 2020; 59:8308-8319. [DOI: 10.1021/acs.inorgchem.0c00691] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Shan Lu
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Tzung-Wen Chiou
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan
| | - Wei-Liang Li
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chun-Chieh Wang
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Yun-Ming Wang
- Department of Biological Science and Technology, Institute of Molecular Medicine and Bioengineering, Center for Intelligent Drug Systems and Smart Bio-devices (IDS2B), National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Way-Zen Lee
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Tsai-Te Lu
- Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Wen-Feng Liaw
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
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Mondal B, Borah D, Mazumdar R, Mondal B. Nitric Oxide Dioxygenase Activity of a Nitrosyl Complex of Mn(II)-Porphyrinate in the Presence of Superoxide: Formation of a Mn(IV)-oxo Species through a Putative Peroxynitrite Intermediate. Inorg Chem 2019; 58:14701-14707. [PMID: 31617355 DOI: 10.1021/acs.inorgchem.9b02359] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A nitrosyl complex of MnII-porphyrinate, [(F20TPP)MnII(NO)], 1 (F20TPPH2 = 5,10,15,20 tetrakis(pentafluorophenyl)porphyrin), was synthesized and characterized. Spectroscopic and structural characterization revealed complex 1 as a penta-coordinated MnII-nitrosyl with a linear Mn-N-O (180.0°) moiety. Complex 1 does not react with O2. However, it reacts with superoxide (O2-) in THF at -80 °C to result in the corresponding nitrate (NO3-) complex, 2, via the formation of a presumed MnIII-peroxynitrite intermediate. ESI-mass spectrometry and UV-visible and X-band EPR spectroscopic studies suggest the generation of MnIV-oxo species in the reaction through homolytic cleavage of the O-O bond of the peroxynitrite ligand as proposed in NOD activity. The intermediate formation of the MnIII-peroxynitrite was further supported by the well accepted phenol ring nitration which resembles the biologically well-established tyrosine nitration.
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Affiliation(s)
- Baishakhi Mondal
- Department of Chemistry , Indian Institute of Technology Guwahati , Assam 781039 , India
| | - Dibyajyoti Borah
- Department of Chemistry , Indian Institute of Technology Guwahati , Assam 781039 , India
| | - Rakesh Mazumdar
- Department of Chemistry , Indian Institute of Technology Guwahati , Assam 781039 , India
| | - Biplab Mondal
- Department of Chemistry , Indian Institute of Technology Guwahati , Assam 781039 , India
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4
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Mondal B, Saha S, Borah D, Mazumdar R, Mondal B. Nitric Oxide Dioxygenase Activity of a Nitrosyl Complex of Cobalt(II) Porphyrinate in the Presence of Hydrogen Peroxide via Putative Peroxynitrite Intermediate. Inorg Chem 2019; 58:1234-1240. [PMID: 30623661 DOI: 10.1021/acs.inorgchem.8b02722] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The reaction of a cobalt porphyrin complex, [(F8TPP)Co], 1 {F8TPP = 5,10,15,20- tetrakis(2,6-difluorophenyl)porphyrinate dianion} in dichloromethane with nitric oxide (NO) led to the nitrosyl complex, [(F8TPP)Co(NO)], 2. Spectroscopic studies and structural characterization revealed it as a bent nitrosyl of {CoNO}8 description. It was stable in the presence of dioxygen. However, it reacts with H2O2 in acetonitrile (or THF) solution at -40 °C (or -80 °C) to result in the corresponding Co(III)-nitrate complex, [(F8TPP)Co(NO3)], 3. The reaction presumably proceeds via the formation of a Co-peroxynitrite intermediate. X-Band electron paramagnetic resonance and electrospray ionization-mass spectroscopic studies suggest the intermediate formation of the [(porphyrin)Co(III)-O•] radical, which in turn supports the generation of the corresponding Co(IV)-oxo species during the reaction. This is in accord with the homolytic cleavage of the O-O bond in heme-peroxynitrite proposed in the nitric oxide dioxygenases activity. In addition, the characteristic peroxynitrite-induced phenol ring reaction was also observed.
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Affiliation(s)
- Baishakhi Mondal
- Department of Chemistry , Indian Institute of Technology Guwahati , North Guwahati , Assam 781039 , India
| | - Soumen Saha
- Department of Chemistry , Indian Institute of Technology Guwahati , North Guwahati , Assam 781039 , India
| | - Dibyajyoti Borah
- Department of Chemistry , Indian Institute of Technology Guwahati , North Guwahati , Assam 781039 , India
| | - Rakesh Mazumdar
- Department of Chemistry , Indian Institute of Technology Guwahati , North Guwahati , Assam 781039 , India
| | - Biplab Mondal
- Department of Chemistry , Indian Institute of Technology Guwahati , North Guwahati , Assam 781039 , India
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5
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Gogoi K, Saha S, Mondal B, Deka H, Ghosh S, Mondal B. Dioxygenation Reaction of a Cobalt-Nitrosyl: Putative Formation of a Cobalt–Peroxynitrite via a {CoIII(NO)(O2–)} Intermediate. Inorg Chem 2017; 56:14438-14445. [PMID: 29131596 DOI: 10.1021/acs.inorgchem.7b01673] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kuldeep Gogoi
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
| | - Soumen Saha
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
| | - Baishakhi Mondal
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
| | - Hemanta Deka
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
| | - Somnath Ghosh
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
| | - Biplab Mondal
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
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6
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Saha S, Ghosh S, Gogoi K, Deka H, Mondal B, Mondal B. Reaction of a Co(III)-Peroxo Complex and NO: Formation of a Putative Peroxynitrite Intermediate. Inorg Chem 2017; 56:10932-10938. [DOI: 10.1021/acs.inorgchem.7b01110] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Soumen Saha
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
| | - Somnath Ghosh
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
| | - Kuldeep Gogoi
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
| | - Hemanta Deka
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
| | - Baishakhi Mondal
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
| | - Biplab Mondal
- Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam 781039, India
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7
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Saha S, Gogoi K, Mondal B, Ghosh S, Deka H, Mondal B. Reaction of a Nitrosyl Complex of Cobalt Porphyrin with Hydrogen Peroxide: Putative Formation of Peroxynitrite Intermediate. Inorg Chem 2017. [DOI: 10.1021/acs.inorgchem.7b00491] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Soumen Saha
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
| | - Kuldeep Gogoi
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
| | - Baishakhi Mondal
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
| | - Somnath Ghosh
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
| | - Hemanta Deka
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
| | - Biplab Mondal
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
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8
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Goodwin JA, Agbo J, Zuczek J, Samuel A, Aslund TH, Tuley LR, Simmons JA, Kimble RJ, Magee E, Creager S, Shetzline J. Electrochemical dioxygen reduction catalyzed by a (nitro)cobalt(perfluorophthalocyanine) complex and the possibility of a peroxynitro complex intermediate. J PORPHYR PHTHALOCYA 2016. [DOI: 10.1142/s1088424615501023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The (nitro)([Formula: see text],[Formula: see text]-dimethyl-4-aminopyridine) complex of perfluorinated cobalt(III) phthalocyanine Co(III)F16Pc(Me2Npy)(NO[Formula: see text] catalyzes the electrochemical oxygen reduction reaction (ORR) in pH 4.0, 7.0, and 10.0 buffer and 0.05 M sulfuric acid solution when deposited on a glassy carbon electrode. Cyclic voltammetry (CV), rotating disk electrode voltammetry (RDE), and rotating ring-disk electrode voltammetry (RRDE) have been used to determine the reduction product as hydrogen peroxide although in concentrations too small to observe by qualitative methods such as oxidation of NaI in solution. The dependence of the values of the peak potentials for the reduction on the pH of the solution and the -log[Me2Npy] are consistent with protonation up to pH 7.6 and pyridine ligand loss during the reduction. The addition of nitrite at 0.1 and 1 M to pH 7.0 solutions in contact with films of CoF16Pc on the glassy carbon electrode decreases the ORR current and shifts the peak potential of the ORR from -0.21 V vs. NHE to -0.19 V vs. NHE. The addition of nitrite at 0.1 and 1 M to films of Co(III)F16Pc(Me2Npy)(NO[Formula: see text] on glassy carbon, however, has no effect on either the current or the potential. While the electrochemical evidence for this proposal is not definitive, modeling has been used to examine the center of reduction in the alternative mechanisms by evaluation of the LUMOs of the hypothetical intermediates in both closed and open shell cases. The formation of five-coordinate Co(II)F16Pc(NO) is proposed to occur initially in the reduction mechanism. It is also possible that O2 reduction takes place at the NO ligand center by way of a nitrogen-bound peroxynitrite intermediate. The [Formula: see text] ligand appears to remain bound during the ORR. Direct coordination of O2 to the metal center requiring a six-coordinate species, Co(III)F16Pc(O[Formula: see text](NO[Formula: see text], Co(II)F16Pc(O[Formula: see text](NO) or [Co(II)F16Pc(O[Formula: see text](NO[Formula: see text]][Formula: see text] and has been considered in DFT modeling studies. The instability of the two-electron reduced, protonation species, [Co(I)F16Pc(NO2OH)][Formula: see text] in its loss of peroxynitrous acid suggests that the reduction of O2 may occur by two one-electron reduction steps rather than a two-electron step.
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Affiliation(s)
- John A. Goodwin
- Coastal Carolina University, Department of Chemistry and Physics, P.O. Box 261954, Conway, South Carolina 29526, USA
| | - Johnson Agbo
- Coastal Carolina University, Department of Chemistry and Physics, P.O. Box 261954, Conway, South Carolina 29526, USA
| | - Justin Zuczek
- Coastal Carolina University, Department of Chemistry and Physics, P.O. Box 261954, Conway, South Carolina 29526, USA
| | - Auquilla Samuel
- Coastal Carolina University, Department of Chemistry and Physics, P.O. Box 261954, Conway, South Carolina 29526, USA
| | - Tyler H. Aslund
- Coastal Carolina University, Department of Chemistry and Physics, P.O. Box 261954, Conway, South Carolina 29526, USA
| | - Leanne R. Tuley
- Coastal Carolina University, Department of Chemistry and Physics, P.O. Box 261954, Conway, South Carolina 29526, USA
| | - Johnathan A. Simmons
- Coastal Carolina University, Department of Chemistry and Physics, P.O. Box 261954, Conway, South Carolina 29526, USA
| | - Robert J. Kimble
- Coastal Carolina University, Department of Chemistry and Physics, P.O. Box 261954, Conway, South Carolina 29526, USA
| | - Erin Magee
- Coastal Carolina University, Department of Chemistry and Physics, P.O. Box 261954, Conway, South Carolina 29526, USA
| | - Stephen Creager
- Clemson University, Department of Chemistry, Clemson, South Carolina 29634, USA
| | - Jamie Shetzline
- Clemson University, Department of Chemistry, Clemson, South Carolina 29634, USA
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9
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Kumar P, Lee YM, Park YJ, Siegler MA, Karlin KD, Nam W. Reactions of Co(III)-nitrosyl complexes with superoxide and their mechanistic insights. J Am Chem Soc 2015; 137:4284-7. [PMID: 25793706 DOI: 10.1021/ja513234b] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
New Co(III)-nitrosyl complexes bearing N-tetramethylated cyclam (TMC) ligands, [(12-TMC)Co(III)(NO)](2+) (1) and [(13-TMC)Co(III)(NO)](2+) (2), were synthesized via [(TMC)Co(II)(CH3CN)](2+) + NO(g) reactions. Spectroscopic and structural characterization showed that these compounds bind the nitrosyl moiety in a bent end-on fashion. Complexes 1 and 2 reacted with KO2/2.2.2-cryptand to produce [(12-TMC)Co(II)(NO2)](+) (3) and [(13-TMC)Co(II)(NO2)](+) (4), respectively; these possess O,O'-chelated nitrito ligands. Mechanistic studies using (18)O-labeled superoxide ((18)O2(•-)) showed that one O atom in the nitrito ligand is derived from superoxide and the O2 produced comes from the other superoxide O atom. Evidence supporting the formation of a Co-peroxynitrite intermediate is also presented.
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Affiliation(s)
- Pankaj Kumar
- †Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
| | - Yong-Min Lee
- †Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
| | - Young Jun Park
- †Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
| | - Maxime A Siegler
- ‡Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Kenneth D Karlin
- ‡Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Wonwoo Nam
- †Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
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Hosokawa H, Funasako Y, Mochida T. Colorimetric solvent indicators based on Nafion membranes incorporating nickel(II)-chelate complexes. Chemistry 2014; 20:15014-20. [PMID: 25308167 DOI: 10.1002/chem.201403996] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Indexed: 11/05/2022]
Abstract
To develop solvent-recognition films, Nafion membranes incorporating cationic nickel-chelate complexes, that is, [Ni(L(1))(L(2))](+) (HL(1) = acetylacetone, 2,2,6,6-tetramethyl-3,5-heptanedione; L(2) = N,N-diethylethylenediamine, N-butyl-N,N',N'-trimethylethylenediamine), were prepared. Immersion of the films in various solvents effected the color changes varying from red to pale blue green depending on the donor number of the solvents. The color change is based on an equilibrium shift between square-planar and solvent-coordinated octahedral geometries of the cations. The degree of the color change depended on the affinity of the incorporated complex to the solvent molecules. The films were robust and exhibited a reversible solvent response. The films exhibited thermochromism when a small amount of appropriate solvents were incorporated and changed from pale blue green at low temperatures to red at high temperatures.
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Affiliation(s)
- Hitoshi Hosokawa
- Department of Chemistry, Graduate School of Science, Kobe University, Rokkodai, Kobe, Hyogo 657-8501 (Japan)
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11
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Kurtikyan TS, Eksuzyan SR, Hayrapetyan VA, Martirosyan GG, Hovhannisyan GS, Goodwin JA. Nitric oxide dioxygenation reaction by oxy-coboglobin models: in-situ low-temperature FTIR characterization of coordinated peroxynitrite. J Am Chem Soc 2012; 134:13861-70. [PMID: 22881578 DOI: 10.1021/ja305774v] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The oxy-cobolglobin models of the general formula (NH(3))Co(Por)(O(2)) (Por = meso-tetra-phenyl and meso-tetra-p-tolylporphyrinato dianions) were constructed by sequential low temperature interaction of NH(3) and dioxygen with microporous layers of Co-porphyrins. At cryogenic temperatures small increments of NO were introduced into the cryostat and the following reactions were monitored by the FTIR and UV-visible spectroscopy during slow warming. Upon warming the layers from 80 to 120 K a set of new IR bands grows with correlating intensities along with the consumption of the ν(O(2)) band. Isotope labeling experiments with (18)O(2), (15)NO and N(18)O along with DFT calculations provides a basis for assigning them to the six-coordinate peroxynitrite complexes (NH(3))Co(Por)(OONO). Over the course of warming the layers from 140 to 170 K these complexes decompose and there are spectral features suggesting the formation of nitrogen dioxide NO(2). Upon keeping the layers at 180-210 K the bands of NO(2) gradually decrease in intensity and the set of new bands grows in the range of 1480, 1270, and 980 cm(-1). These bands have their isotopic counterparts when (15)NO, (18)O(2) and N(18)O are used in the experiments and certainly belong to the 6-coordinate nitrato complexes (NH(3))Co(Por)(η(1)-ONO(2)) demonstrating the ability of oxy coboglobin models to promote the nitric oxide dioxygenation (NOD) reaction similar to oxy-hemes. As in the case of Hb, Mb and model iron-porphyrins, the six-coordinate nitrato complexes are not stable at room temperature and dissociate to give nitrate anion and oxidized cationic complex Co(III)(Por)(NH(3))(1,2).
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Affiliation(s)
- Tigran S Kurtikyan
- Molecule Structure Research Centre (MSRC) of the Scientific and Technological Centre of Organic and Pharmaceutical Chemistry NAS, 0014, Yerevan, Armenia.
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12
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Goodwin JA, Kurtikyan TS. Electrocatalytic reactions of dioxygen and nitric oxide with reduced (nitrosyl) cobalt porphyrins — cyclic voltammetry and computational chemistry. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424611003033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Water-soluble cationic cobalt(tetra(N-methyl-pyridyl)porphyrins, CoTMpyP(4) and CoTMpyP(2) and the β-pyrrole octabrominated derivative CoTMpyP(4)Br8 have been studied by cyclic voltammetry under aqueous aerobic conditions at pH of 4.0 with and without addition of nitrite to explore their ability to catalyze the reduction of dioxygen. The porphyrins and their nitro/nitrosyl derivatives were studied in aqueous acetate buffer solution at a solid silver electrode and then also as they were immobilized in Nafion® film loaded with silver nanoparticles which provided electrical conductivity. Under these reducing conditions with nitrite in solution, coordinated nitrite appears to undergo an oxo-transfer/reduction reaction resulting in the formation of the nitrosyl ligand. The reaction of the nitrosyl complex allows a short-lived electrocatalytic reduction reaction with dioxygen before NO is lost from the complex by dissociation. The thermodynamics of the reactions and possible catalytic intermediates in the reduction of dioxygen were studied by DFT (BP/6-31G*) computations. An unusual N -bound cyclic NO3- structure was obtained in the optimized geometries for the product of reduced nitrosyl porphyrins and dioxygen in the model complexes and for [CoTMpyP(2)(NO-O2)]- . These structures are tentatively proposed to represent an intermediate in the mechanism of activation of dioxygen in catalytic reduction. DFT (BP/6-31G*) computations were also applied to probe thermodynamics and intermediates in the known catalytic reduction of NO to N2O by the reduced porphyrin under anaerobic conditions. Thermodynamics estimates suggest that reduction occurs through coordinated NO in the reduced porphyrin species similar to cytochrome P450nor (nitric oxide reductase), but the detailed mechanism is not clear.
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Affiliation(s)
- John A. Goodwin
- Coastal Carolina University, Department of Chemistry and Physics, PO Box 261954, Conway, South Carolina, 29526, USA
| | - Tigran S. Kurtikyan
- Molecule Structure Research Center of the Scientific Technological Center of Organic and Pharmaceutical, Chemistry NAS, Armenia
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Tonezzer M, Maggioni G, Dalcanale E. Production of novel microporous porphyrin materials with superior sensing capabilities. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm15008e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Co(II) complexes with tripodal N-donor ligands: Thermodynamics of formation in anaerobic conditions and oxygen binding. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2010.12.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Ali BB, Belkhiria MS, Giorgi M, Nasri H. Synthesis, structural and spectroscopic characterization of the bis(nitrito-<i>N</i>) octaethylporphyrin cobalt(III) complex. ACTA ACUST UNITED AC 2011. [DOI: 10.4236/ojic.2011.13006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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