1
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Lohmeyer L, Werr M, Kaifer E, Himmel H. Interplay and Competition Between Two Different Types of Redox-Active Ligands in Cobalt Complexes: How to Allocate the Electrons? Chemistry 2022; 28:e202201789. [PMID: 35894809 PMCID: PMC9804828 DOI: 10.1002/chem.202201789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Indexed: 01/09/2023]
Abstract
The field of molecular transition metal complexes with redox-active ligands is dominated by compounds with one or two units of the same redox-active ligand; complexes in which different redox-active ligands are bound to the same metal are uncommon. This work reports the first molecular coordination compounds in which redox-active bisguanidine or urea azine (biguanidine) ligands as well as oxolene ligands are bound to the same cobalt atom. The combination of two different redox-active ligands leads to mono- as well as unprecedented dinuclear cobalt complexes, being multiple (four or six) center redox systems with intriguing electronic structures, all exhibiting radical ligands. By changing the redox potential of the ligands through derivatisation, the electronic structure of the complexes could be altered in a rational way.
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Affiliation(s)
- Lukas Lohmeyer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Marco Werr
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Hans‐Jörg Himmel
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
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2
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Gallego CM, Mazzeo A, Gaviglio C, Pellegrino J, Doctorovich F. Structure and Reactivity of NO/NO
+
/NO
−
Pincer and Porphyrin Complexes. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Cecilia Mariel Gallego
- Departamento de Química Inorgánica, Analítica y Química Física Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires Pabellón 2, Ciudad Universitaria Buenos Aires Argentina
| | - Agostina Mazzeo
- Departamento de Química Inorgánica, Analítica y Química Física Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires Pabellón 2, Ciudad Universitaria Buenos Aires Argentina
| | - Carina Gaviglio
- Departamento de Física de la Materia Condensada Comisión Nacional de Energía Atómica, CAC-GIyANN Avenida General Paz 1499, San Martín Buenos Aires Argentina
| | - Juan Pellegrino
- Departamento de Química Inorgánica, Analítica y Química Física Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires Pabellón 2, Ciudad Universitaria Buenos Aires Argentina
| | - Fabio Doctorovich
- Departamento de Química Inorgánica, Analítica y Química Física Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires Pabellón 2, Ciudad Universitaria Buenos Aires Argentina
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3
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Gallego CM, Mazzeo A, Vargas P, Suárez S, Pellegrino J, Doctorovich F. Azanone (HNO): generation, stabilization and detection. Chem Sci 2021; 12:10410-10425. [PMID: 34447533 PMCID: PMC8356739 DOI: 10.1039/d1sc02236a] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 07/05/2021] [Indexed: 12/14/2022] Open
Abstract
HNO (nitroxyl, azanone), joined the 'biologically relevant reactive nitrogen species' family in the 2000s. Azanone is impossible to store due to its high reactivity and inherent low stability. Consequently, its chemistry and effects are studied using donor compounds, which release this molecule in solution and in the gas phase upon stimulation. Researchers have also tried to stabilize this elusive species and its conjugate base by coordination to metal centers using several ligands, like metalloporphyrins and pincer ligands. Given HNO's high reactivity and short lifetime, several different strategies have been proposed for its detection in chemical and biological systems, such as colorimetric methods, EPR, HPLC, mass spectrometry, fluorescent probes, and electrochemical analysis. These approaches are described and critically compared. Finally, in the last ten years, several advances regarding the possibility of endogenous HNO generation were made; some of them are also revised in the present work.
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Affiliation(s)
- Cecilia Mariel Gallego
- Departamento de Química Inorgánica, Analítica, y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria Pab. 2 C1428EHA Buenos Aires Argentina
| | - Agostina Mazzeo
- Departamento de Química Inorgánica, Analítica, y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria Pab. 2 C1428EHA Buenos Aires Argentina
| | - Paola Vargas
- Departamento de Química Inorgánica, Analítica, y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria Pab. 2 C1428EHA Buenos Aires Argentina
| | - Sebastián Suárez
- Departamento de Química Inorgánica, Analítica, y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria Pab. 2 C1428EHA Buenos Aires Argentina
| | - Juan Pellegrino
- Departamento de Química Inorgánica, Analítica, y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria Pab. 2 C1428EHA Buenos Aires Argentina
| | - Fabio Doctorovich
- Departamento de Química Inorgánica, Analítica, y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria Pab. 2 C1428EHA Buenos Aires Argentina
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4
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Xu W, Fang Y, Ou Z, Chen M, Kadish KM. Synthesis, electrochemical and spectroelectrochemical characterization of iron(III) tetraarylporphyrins containing four β,β′-butano and β,β′-benzo fused rings. J PORPHYR PHTHALOCYA 2018. [DOI: 10.1142/s1088424618500517] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Six iron(III) tetraarylporphyrins containing four [Formula: see text]-butano or [Formula: see text]-benzo fused rings were synthesized and characterized by electrochemistry and spectroelectrochemistry in nonaqueous media. The examined compounds are represented as butano(TpYPP)FeCl and benzo(TpYPP)FeCl, where TpYPP is a dianion of the meso-substituted porphyrin, Y is a CH[Formula: see text], H or Cl substituent on the para-position of the four meso-phenyl rings and butano and benzo are the [Formula: see text]-substituents on each of the four pyrrole rings of the compound. Up to three reductions are observed for each Fe(III) butano- and benzoporphyrin in CH[Formula: see text]Cl[Formula: see text] or pyridine containing 0.1 M TBAP, the first of which is assigned in each case to a metal-centered electron transfer. The second reduction is also metal-centered in CH[Formula: see text]Cl[Formula: see text] and leads to formation of an Fe(I) porphyrin, but it is porphyrin ring-centered and gives an Fe(II) porphyrin [Formula: see text]-anion radical reduction product when pyridine is used as the solvent. The effects of the solvent and type of fused ring system (butano or benzo) on the UV-vis spectra and electrochemical properties of the Fe(III) porphyrins are discussed and comparisons are made to both the structurally related non-[Formula: see text]-substituted iron porphyrins and earlier described butano- or benzotetraarylporphyrins containing Cu(II) or Co(II) central metal ions.
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Affiliation(s)
- Weijie Xu
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Yuanyuan Fang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Zhongping Ou
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, China
- Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA
| | - Mingyuan Chen
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, China
- Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA
| | - Karl M. Kadish
- Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA
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5
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Abucayon EG, Khade RL, Powell DR, Zhang Y, Richter-Addo GB. Lewis Acid Activation of the Ferrous Heme-NO Fragment toward the N-N Coupling Reaction with NO To Generate N 2O. J Am Chem Soc 2018; 140:4204-4207. [PMID: 29502400 DOI: 10.1021/jacs.7b13681] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Bacterial NO reductase (bacNOR) enzymes utilize a heme/non-heme active site to couple two NO molecules to N2O. We show that BF3 coordination to the nitrosyl O-atom in (OEP)Fe(NO) activates it toward N-N bond formation with NO to generate N2O. 15N-isotopic labeling reveals a reversible nitrosyl exchange reaction and follow-up N-O bond cleavage in the N2O formation step. Other Lewis acids (B(C6F5)3 and K+) also promote the NO coupling reaction with (OEP)Fe(NO). These results, complemented by DFT calculations, provide experimental support for the cis: b3 pathway in bacNOR.
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Affiliation(s)
- Erwin G Abucayon
- Department of Chemistry and Biochemistry , University of Oklahoma , Norman , Oklahoma 73019 , United States
| | - Rahul L Khade
- Department of Chemistry and Chemical Biology , Stevens Institute of Technology , Castle Point on Hudson , Hoboken , New Jersey 07030 , United States
| | - Douglas R Powell
- Department of Chemistry and Biochemistry , University of Oklahoma , Norman , Oklahoma 73019 , United States
| | - Yong Zhang
- Department of Chemistry and Chemical Biology , Stevens Institute of Technology , Castle Point on Hudson , Hoboken , New Jersey 07030 , United States
| | - George B Richter-Addo
- Department of Chemistry and Biochemistry , University of Oklahoma , Norman , Oklahoma 73019 , United States
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6
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Commins PJ, Hill JP, Matsushita Y, Webre WA, Labuta J, Ariga K, D’Souza F. Selective octabromination of tetraarylporphyrins based on meso-substituent identity: Structural and electrochemical studies. J PORPHYR PHTHALOCYA 2016. [DOI: 10.1142/s1088424615500972] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Synthesis and isolation of selectively brominated tetraarylporphyrin derivatives is reported. Treatment with bromine of meso-5,10,15,20-tetrakis(3,4,5-trimethoxyphenyl)porphyrin (1) or meso-5,10,15,20-tetrakis(3,5-di-[Formula: see text]-butyl-4-hydroxyphenyl)porphinatocopper(II) (2-Cu) yields products octabrominated at the 2,6-positions of meso-aryl substituents [5,10,15,20-tetrakis(2,6-dibromo-3,4,5-trimethoxyphenyl)porphyrin, [Formula: see text]Br81] or macrocyclic [Formula: see text]-positions. The latter of these ([Formula: see text]-brominated) was identified as the oxoporphyrinogen 2,3,7,8,12,13,17,18-octabromo-5,10,15,20- tetrakis(3,5-di-[Formula: see text]-butyl-4-oxo-cyclohexa-2,5-dienylidene)porphyrinogen 3 obtained due to the adventitious oxidation and demetalation of 2-Cu, which could be alkylated at its macrocyclic nitrogen atoms yielding N[Formula: see text],N[Formula: see text],N[Formula: see text],N[Formula: see text]-tetrakis(4-bromobenzyl)-2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(3,5-di-[Formula: see text]-butyl-4-oxo-cyclo hexa-2,5-dienylidene)porphyrinogen 4. The former compound [Formula: see text]Br81 was complexed with Zn(II) ([Formula: see text]Br81-Zn) or Cu(II) ([Formula: see text]Br81-Cu) and could also be subjected to further bromination yielding 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(2,6-dibromo-3,4,5-trimethoxyphenyl)porphyrin, Br[Formula: see text]1. The effect on the electrochemical properties of the 2,6-bromophenyl-substituted porphyrin compounds over the more highly brominated products was assessed.
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Affiliation(s)
- Patrick J. Commins
- Supermolecules Group, International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA
| | - Jonathan P. Hill
- Supermolecules Group, International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Yoshitaka Matsushita
- Research Network and Facility Services Division, National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Whitney A. Webre
- Department of Chemistry, University of North Texas, 1155 Union Circle, Denton, #305070, Texas 76203-5017, USA
| | - Jan Labuta
- International Center for Young Scientists, National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Katsuhiko Ariga
- Supermolecules Group, International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Francis D’Souza
- Department of Chemistry, University of North Texas, 1155 Union Circle, Denton, #305070, Texas 76203-5017, USA
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7
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Foi A, Di Salvo F, Doctorovich F, Roy TG, Stirnat K, Biewer C, Klein A. Tracing the Iron Nitrosyl Complex [Fe(2,2′‐bipyridine)(CN)
3
(NO)]
–. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201403145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ana Foi
- Departamento de Química Inorgánica, Analítica, y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE‐CONICET, Ciudad Universitaria, Pabellón 2, Piso 3, C1428EHA Buenos Aires, Argentina
| | - Florencia Di Salvo
- Departamento de Química Inorgánica, Analítica, y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE‐CONICET, Ciudad Universitaria, Pabellón 2, Piso 3, C1428EHA Buenos Aires, Argentina
| | - Fabio Doctorovich
- Departamento de Química Inorgánica, Analítica, y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE‐CONICET, Ciudad Universitaria, Pabellón 2, Piso 3, C1428EHA Buenos Aires, Argentina
| | | | - Kathrin Stirnat
- Universität zu Köln, Institut für Anorganische Chemie, Greinstraße 6, 50939 Köln, http://www.klein.uni‐koeln.de/
| | - Christian Biewer
- Universität zu Köln, Institut für Anorganische Chemie, Greinstraße 6, 50939 Köln, http://www.klein.uni‐koeln.de/
| | - Axel Klein
- Universität zu Köln, Institut für Anorganische Chemie, Greinstraße 6, 50939 Köln, http://www.klein.uni‐koeln.de/
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8
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Kaim W. Complete and Partial Electron Transfer Involving Coordinated NOx. ADVANCES IN INORGANIC CHEMISTRY 2015. [DOI: 10.1016/bs.adioch.2014.10.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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9
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Doctorovich F, Bikiel DE, Pellegrino J, Suárez SA, Martí MA. Reactions of HNO with metal porphyrins: underscoring the biological relevance of HNO. Acc Chem Res 2014; 47:2907-16. [PMID: 25238532 DOI: 10.1021/ar500153c] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Azanone ((1)HNO, nitroxyl) shows interesting yet poorly understood chemical and biological effects. HNO has some overlapping properties with nitric oxide (NO), sharing its biological reactivity toward heme proteins, thiols, and oxygen. Despite this similarity, HNO and NO show significantly different pharmacological effects. The high reactivity of HNO means that studies must rely on the use of donor molecules such as trioxodinitrate (Angeli's salt). It has been suggested that azanone could be an intermediate in several reactions and that it may be an enzymatically produced signaling molecule. The inherent difficulty in detecting its presence unequivocally prevents evidence from yielding definite answers. On the other hand, metalloporphyrins are widely used as chemical models of heme proteins, providing us with invaluable tools for the study of the coordination chemistry of small molecules, like NO, CO, and O2. Studies with transition metal porphyrins have shown diverse mechanistic, kinetic, structural, and reactive aspects related to the formation of nitrosyl complexes. Porphyrins are also widely used in technical applications, especially when coupled to a surface, where they can be used as electrochemical gas sensors. Given their versatility, they have not escaped their role as key players in chemical studies involving HNO. This Account presents the research performed during the last 10 years in our group concerning azanone reactions with iron, manganese, and cobalt porphyrins. We begin by describing their HNO trapping capabilities, which result in formation of the corresponding nitrosyl complexes. Kinetic and mechanistic studies of these reactions show two alternative operating mechanisms: reaction of the metal center with HNO or with the donor. Moreover, we have also shown that azanone can be stabilized by coordination to iron porphyrins using electron-attracting substituents attached to the porphyrin ring, which balance the negatively charged NO¯. Second, we describe an electrochemical HNO sensing device based on the covalent attachment of a cobalt porphyrin to gold. A surface effect affects the redox potentials and allows discrimination between HNO and NO. The reaction with the former is fast, efficient, and selective, lacking spurious signals due to the presence of reactive nitrogen and oxygen species. The sensor is both biologically compatible and highly sensitive (nanomolar). This time-resolved detection allows kinetic analysis of reactions producing HNO. The sensor thus offers excellent opportunities to be used in experiments looking for HNO. As examples, we present studies concerning (a) HNO donation capabilities of new HNO donors as assessed by the sensor, (b) HNO detection as an intermediate in O atom abstraction to nitrite by phosphines, and (c) NO to HNO interconversion mediated by alcohols and thiols. Finally, we briefly discuss the key experiments required to demonstrate endogenous HNO formation to be done in the near future, involving the in vivo use of the HNO sensing device.
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Affiliation(s)
- Fabio Doctorovich
- Departamento de Química Inorgánica,
Analítica
y Química Física/INQUIMAE-CONICET and †Departamento de Química
Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II (1428), Buenos Aires, Argentina
| | - Damian E. Bikiel
- Departamento de Química Inorgánica,
Analítica
y Química Física/INQUIMAE-CONICET and †Departamento de Química
Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II (1428), Buenos Aires, Argentina
| | - Juan Pellegrino
- Departamento de Química Inorgánica,
Analítica
y Química Física/INQUIMAE-CONICET and †Departamento de Química
Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II (1428), Buenos Aires, Argentina
| | - Sebastián A. Suárez
- Departamento de Química Inorgánica,
Analítica
y Química Física/INQUIMAE-CONICET and †Departamento de Química
Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II (1428), Buenos Aires, Argentina
| | - Marcelo A. Martí
- Departamento de Química Inorgánica,
Analítica
y Química Física/INQUIMAE-CONICET and †Departamento de Química
Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II (1428), Buenos Aires, Argentina
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10
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Berto TC, Xu N, Lee SR, McNeil AJ, Alp EE, Zhao J, Richter-Addo GB, Lehnert N. Characterization of the Bridged Hyponitrite Complex {[Fe(OEP)]2(μ-N2O2)}: Reactivity of Hyponitrite Complexes and Biological Relevance. Inorg Chem 2014; 53:6398-414. [DOI: 10.1021/ic5002573] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Timothy C. Berto
- Department
of Chemistry and Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Nan Xu
- Department
of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson
Parkway, Norman, Oklahoma 73019, United States
| | - Se Ryeon Lee
- Department
of Chemistry and Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Anne J. McNeil
- Department
of Chemistry and Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - E. Ercan Alp
- Argonne National Laboratory, APS/XFD, 431/D003, Argonne, Illinois 60439, United States
| | - Jiyong Zhao
- Argonne National Laboratory, APS/XFD, 431/D003, Argonne, Illinois 60439, United States
| | - George B. Richter-Addo
- Department
of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson
Parkway, Norman, Oklahoma 73019, United States
| | - Nicolai Lehnert
- Department
of Chemistry and Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
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11
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Xu N, Powell DR, Richter-Addo GB. Synthesis, molecular structure, and spectroelectrochemistry of a nitrosyl iron porphyrin containing an unsymmetrical xanthene-linked porphyrin core. Nitric Oxide 2014; 37:61-5. [PMID: 24447916 DOI: 10.1016/j.niox.2014.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 12/05/2013] [Accepted: 01/09/2014] [Indexed: 11/19/2022]
Abstract
Synthetic nitrosyl porphyrins with meso-aryl substituents are potential models for the biologically-important NO-bound P460 heme cofactor. A five-coordinate iron nitrosyl tetraaryl-porphyrin (HTPPX-CO2H)Fe(NO) containing a xanthene-based meso substituent has been prepared. The crystal structure of this formally {FeNO}7 complex reveals an ordered axial and bent NO ligand (∠FeNO=142.5(6)Å) displaying an off-axis tilt of the nitrosyl N atom from the heme normal by 9.2°. Surprisingly, the porphyrin core does not display the expected asymmetry in FeN(por) distances frequently observed in iron nitrosyl porphyrins. The redox behavior as determined by cyclic voltammetry reveals, in contrast to most (por)Fe(NO) compounds, a fast NO dissociation after electrooxidation in CH2Cl2 to result in a net chemically-irreversible oxidation at Epa=+0.77V vs Ag/AgCl. IR spectroelectrochemistry reveals a recombination, on the spectroelectrochemistry time-scale, of the dissociated NO on oxidation with electrogenerated [(HTPPX-CO2H)Fe]+.
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Affiliation(s)
- Nan Xu
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK 73019, USA
| | - Douglas R Powell
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK 73019, USA
| | - George B Richter-Addo
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK 73019, USA.
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12
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Broclawik E, Stępniewski A, Radoń M. Nitric oxide as a non-innocent ligand in (bio-)inorganic complexes: spin and electron transfer in Fe(II)-NO bond. J Inorg Biochem 2014; 136:147-53. [PMID: 24495545 DOI: 10.1016/j.jinorgbio.2014.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 01/10/2014] [Accepted: 01/10/2014] [Indexed: 11/27/2022]
Abstract
The nature of electron density transfer upon bond formation between NO ligand and Fe(II) center is analyzed on the basis of DFT calculation for two {Fe-NO}(7) complexes with entirely diverse geometric and electronic structures: Fe(II)P(NH3)NO (with bent Fe-N-O unit) and [Fe(II)(H2O)5(NO)](2+) (with linear Fe-N-O structure). Proper identification of an electronic status of the fragments, "prepared" to make a bond, was found necessary to get meaningful resolution of charge and spin transfer processes from a spin-resolved analysis of natural orbitals for chemical valence. The Fe(II)P(NH3)NO adduct (built of NO(0) (S=1/2) and Fe(II)P(NH3) (S=0) fragments) showed a strong π*-backdonation competing with spin transfer via a σ-donation, yielding significant red-shift of the NO stretching frequency. [Fe(II)(H2O)5(NO)](2+) (built of NO(0) (S=1/2) antiferromagnetically coupled to Fe(II)(H2O)5 (S=2) fragment) gave no noticeable charge or spin transfer between fragments; a slight blue-shift of the NO stretching frequency could be related to a residual π-donation due to weak π-bonding.
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Affiliation(s)
- Ewa Broclawik
- Jerzy Haber Institute of Catalysis PAS, ul. Niezapominajek 8, 30-239 Krakow, Poland.
| | - Adam Stępniewski
- Jerzy Haber Institute of Catalysis PAS, ul. Niezapominajek 8, 30-239 Krakow, Poland
| | - Mariusz Radoń
- Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland
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13
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Weisser F, Klein JEMN, Sarkar B, Plietker B. Spectroelectrochemical investigation of Bu4N[Fe(CO)3(NO)]: identification of a reversible EC-mechanism. Dalton Trans 2014; 43:883-7. [PMID: 24158594 DOI: 10.1039/c3dt51998h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bu4N[Fe(CO)3(NO)] displays unique catalytic properties in electron-transfer catalysis such as in allylic substitutions, hydrosilylation, transesterifications, or carbene transfer chemistry. Herein we present a detailed spectroelectrochemical investigation of this complex that unravels an interesting electrochemical-chemical transformation in which two parts of [Fe(CO)3(NO)](-) are oxidized and undergo a disproportionation in the presence of CO to [Fe(CO)5] and [Fe(CO)2(NO)2]. Upon re-reduction the former two complexes regenerate [Fe(CO)3(NO)](-) to about 85%.
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Affiliation(s)
- Fritz Weisser
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, DE-14195 Berlin, Germany
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14
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Emel’yanova NS, Shestakov AF, Sanina NA, Aldoshin SM. Quantum chemical modeling of the stability of reduced forms of Roussin’s red esters. Effect of the nature of the ligand. Russ Chem Bull 2013. [DOI: 10.1007/s11172-013-0046-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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15
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Pellegrino J, Gaviglio C, Milstein D, Doctorovich F. Electron Transfer Behavior of Pincer-Type {RhNO}8 Complexes: Spectroscopic Characterization and Reactivity of Paramagnetic {RhNO}9 Complexes. Organometallics 2013. [DOI: 10.1021/om4008746] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Juan Pellegrino
- Departamento
de Química Inorgánica, Analítica, y Química
Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria, Pab. 2, C1428EHA, Buenos Aires, Argentina
| | - Carina Gaviglio
- Departamento
de Química Inorgánica, Analítica, y Química
Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria, Pab. 2, C1428EHA, Buenos Aires, Argentina
| | - David Milstein
- Department
of Organic Chemistry and Department of Chemical Research Support, The Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Fabio Doctorovich
- Departamento
de Química Inorgánica, Analítica, y Química
Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria, Pab. 2, C1428EHA, Buenos Aires, Argentina
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16
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Yang S, Sun B, Ou Z, Meng D, Lu G, Fang Y, Kadish KM. β-Nitro-substituted free-base, iron(III) and manganese(III) tetraarylporphyrins: synthesis, electrochemistry and effect of the NO2 substituent on spectra and redox potentials in non-aqueous media. J PORPHYR PHTHALOCYA 2013. [DOI: 10.1142/s1088424613500612] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Two free-base and four metal derivatives of substituted tetraarylporphyrins containing a nitro-substituent on the β-pyrrole position of the macrocycle were synthesized and characterized by UV-vis, FTIR, 1 H NMR and mass spectrometry as well as electrochemistry and spectroelectrochemistry in non-aqueous media. The porphyrins are represented as ( NO 2 TmPP ) M and ( NO 2 TdmPP ) M , where M = 2 H , Fe III Cl or Mn III Cl , m is a CH 3 group on the para-position of the four meso-phenyl rings of the tetraphenylporphyrin (TPP) and dm represents two OCH 3 substituents on the meta-positions of each phenyl ring of the TPP macrocycle. UV-visible spectra of the nitro-substituted porphyrins exhibit absorption bands which are red-shifted by 4–11 nm as compared to bands of the same substituted tetraarylporphyrins lacking a nitro substituent. Three or four reductions are observed for each iron and manganese nitroporphyrin, the first of which is metal-centered, leading to formation of an Fe ( II ) or Mn ( II ) complex. Further reduction at the metal center occurs for the iron porphyrins but this reaction proceeds via an Fe ( II ) π anion radical in the case of the two nitro-substituented derivatives. The β-nitro-substituted porphyrins are easier to reduce and harder to oxidize than the corresponding compounds lacking a nitro group. The effect of NO 2 substituent on reduction/oxidation potentials and the site of electron transfer was also discussed.
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Affiliation(s)
- Shuibo Yang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Bin Sun
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Zhongping Ou
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Deying Meng
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Guifen Lu
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Yuanyuan Fang
- Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA
| | - Karl M. Kadish
- Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA
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17
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Sanders BC, Patra AK, Harrop TC. Synthesis, properties, and reactivity of a series of non-heme {FeNO}7/8 complexes: Implications for Fe-nitroxyl coordination. J Inorg Biochem 2013; 118:115-27. [DOI: 10.1016/j.jinorgbio.2012.08.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 08/17/2012] [Accepted: 08/18/2012] [Indexed: 10/27/2022]
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18
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Sanders BC, Rhine MA, Harrop TC. Properties of {FeNO}8 and {CoNO}9 Metal Nitrosyls in Relation to Nitroxyl Coordination Chemistry. MOLECULAR DESIGN IN INORGANIC BIOCHEMISTRY 2013. [DOI: 10.1007/430_2012_87] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Lehnert N, Scheidt WR, Wolf MW. Structure and Bonding in Heme–Nitrosyl Complexes and Implications for Biology. NITROSYL COMPLEXES IN INORGANIC CHEMISTRY, BIOCHEMISTRY AND MEDICINE II 2013. [DOI: 10.1007/430_2013_92] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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20
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Kalmár J, Biri B, Lente G, Bányai I, Budimir A, Biruš M, Batinić-Haberle I, Fábián I. Detailed mechanism of the autoxidation of N-hydroxyurea catalyzed by a superoxide dismutase mimic Mn(III) porphyrin: formation of the nitrosylated Mn(II) porphyrin as an intermediate. Dalton Trans 2012; 41:11875-84. [PMID: 22911446 DOI: 10.1039/c2dt31200j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The in vitro autoxidation of N-hydroxyurea (HU) is catalyzed by Mn(III)TTEG-2-PyP(5+), a synthetic water soluble Mn(III) porphyrin which is also a potent mimic of the enzyme superoxide dismutase. The detailed mechanism of the reaction is deduced from kinetic studies under basic conditions mostly based on data measured at pH = 11.7 but also including some pH-dependent observations in the pH range 9-13. The major intermediates were identified by UV-vis spectroscopy and electrospray ionization mass spectrometry. The reaction starts with a fast axial coordination of HU to the metal center of Mn(III)TTEG-2-PyP(5+), which is followed by a ligand-to-metal electron transfer to get Mn(II)TTEG-2-PyP(4+) and the free radical derived from HU (HU˙). Nitric oxide (NO) and nitroxyl (HNO) are minor intermediates. The major pathway for the formation of the most significant intermediate, the {MnNO} complex of Mn(II)TTEG-2-PyP(4+), is the reaction of Mn(II)TTEG-2-PyP(4+) with NO. We have confirmed that the autoxidation of the intermediates opens alternative reaction channels, and the process finally yields NO(2)(-) and the initial Mn(III)TTEG-2-PyP(5+). The photochemical release of NO from the {MnNO} intermediate was also studied. Kinetic simulations were performed to validate the deduced rate constants. The investigated reaction has medical implications: the accelerated production of NO and HNO from HU may be utilized for therapeutic purposes.
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Affiliation(s)
- József Kalmár
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary H-4010, POB-21
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21
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Liu N, Yin P, Chen Y, Deng Y, He L. Preparation of α-Sulfonylethanone Oximes from Oxidized Hydroxylamine. European J Org Chem 2012. [DOI: 10.1002/ejoc.201200133] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
The potential of redox-active ligands to behave "noninnocently" in transition-metal coordination compounds is reflected with respect to various aspects and situations. These include the question of establishing "correct" oxidation states, the identification and characterization of differently charged radical ligands, the listing of structural and other consequences of ligand redox reactions, and the distinction between barrierless delocalized "resonance" cases M(n)/L(n) ↔ M(n+1)L(n-1) versus separated valence tautomer equilibrium situations M(n)/L(n) ⇌ M(n+1)L(n-1). Further ambivalence arises for dinuclear systems with radical bridge M(n)(μ-L(•))M(n) versus mixed-valent alternatives M(n+1)(μ-L(-))M(n), for noninnocent ligand-bridged coordination compounds of higher nuclearity such as (μ(3)-L)M(3), (μ(4)-L)M(4), (μ-L)(4)M(4), or coordination polymers. Conversely, the presence of more than one noninnocently behaving ligand at a single transition-metal site in situations such as L(n)-M-L(n-1) or L(•)-M-L(•) may give rise to corresponding ligand-to-ligand interaction phenomena (charge transfer, electron hopping, and spin-spin coupling) and to redox-induced electron transfer with counterintuitive oxidation-state changes. The relationships of noninnocent ligand behavior with excited-state descriptions and perspectives regarding material properties and single-electron or multielectron reactivity are also illustrated briefly.
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Affiliation(s)
- Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany.
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