1
|
Rebilly JN, Herrero C, Sénéchal-David K, Guillot R, Banse F. Catalytic oxidation properties of an acid-resistant cross-bridged cyclen Fe(II) complex. Influence of the rigid donor backbone and protonation on the reactivity. Dalton Trans 2023. [PMID: 37334566 DOI: 10.1039/d3dt00393k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
The catalytic properties of an iron complex bearing a pentadentate cross-bridged ligand backbone are reported. With H2O2 as an oxidant, it displays moderate conversions in epoxidation and alkane hydroxylation and satisfactory ones in aromatic hydroxylation. Upon addition of an acid to the reaction medium, a significant enhancement in aromatic and alkene oxidation is observed. Spectroscopic analyses showed that accumulation of the expected FeIII(OOH) intermediate is limited under these conditions, unless an acid is added to the mixture. This is ascribed to the inertness induced by the cross-bridged ligand backbone, which is partly reduced under acidic conditions.
Collapse
Affiliation(s)
- Jean-Noël Rebilly
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), 91405 Orsay cedex, France.
| | - Christian Herrero
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), 91405 Orsay cedex, France.
| | - Katell Sénéchal-David
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), 91405 Orsay cedex, France.
| | - Régis Guillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), 91405 Orsay cedex, France.
| | - Frédéric Banse
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), 91405 Orsay cedex, France.
| |
Collapse
|
2
|
Wu GL, Zheng CY. MODELS FOR LIPOXYGENASE WITH TWO ALKOXIDE–Fe(III) CENTERS: SYNTHESIS, STRUCTURES, AND PROPERTIES. J STRUCT CHEM+ 2022. [DOI: 10.1134/s0022476622040151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
3
|
Jia S, Fan L, Zheng CY, Jin S, Li D. Mixed-valence {FeII2FeIII4} hexanuclear complexes with thermally induced Fe(III) spin crossover behavior. Dalton Trans 2022; 51:12968-12974. [DOI: 10.1039/d2dt02041f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cyano-bridged mixed-valence {Fe6} hexanuclear complexes {[Tp4-MeFeII(CN)3]2[FeIII(Tpa)]2[FeIII(OR)(Tpa)]2}·6ClO4·S {Tp4-Me = tri(4-methyl-pyrazol-1-yl)borate, Tpa = Tris(2-pyridylmethyl)amine; R = -CH3 S = 8MeOH 1, R = -C2H5 S = 6EtOH 2 } have been obtained...
Collapse
|
4
|
Synthesis, reactivity, and DFT studies of a series of non-heme alkoxoiron(III) complexes as models for lipoxygenase. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
5
|
Asik D, Abozeid SM, Turowski SG, Spernyak JA, Morrow JR. Dinuclear Fe(III) Hydroxypropyl-Appended Macrocyclic Complexes as MRI Probes. Inorg Chem 2021; 60:8651-8664. [PMID: 34110140 PMCID: PMC9942924 DOI: 10.1021/acs.inorgchem.1c00634] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Four high-spin Fe(III) macrocyclic complexes, including three dinuclear and one mononuclear complex, were prepared toward the development of more effective iron-based magnetic resonance imaging (MRI) contrast agents. All four complexes contain a 1,4,7-triazacyclononane macrocyclic backbone with two hydroxypropyl pendant groups, an ancillary aryl or biphenyl group, and a coordination site for a water ligand. The pH potentiometric titrations support one or two deprotonations of the complexes, most likely deprotonation of hydroxypropyl groups at near-neutral pH. Variable-temperature 17O NMR studies suggest that the inner-sphere water ligand is slow to exchange with bulk water on the NMR time scale. Water proton T1 relaxation times measured for solutions of the Fe(III) complexes at pH 7.2 showed that the dinuclear complexes have a 2- to 3-fold increase in r1 relaxivity in comparison to the mononuclear complex per molecule at field strengths ranging from 1.4 T to 9.4 T. The most effective agent, a dinuclear complex with macrocycles linked through para-substitution of an aryl group (Fe2(PARA)), has an r1 of 6.7 mM-1 s-1 at 37 °C and 4.7 T or 3.3 mM-1 s-1 per iron center in the presence of serum albumin and shows enhanced blood pool and kidney contrast in mice MRI studies.
Collapse
Affiliation(s)
- Didar Asik
- Department of Chemistry, University at Buffalo, State University of New York, Amherst, New York 14260, United States
| | - Samira M. Abozeid
- Department of Chemistry, University at Buffalo, State University of New York, Amherst, New York 14260, United States
| | - Steven G. Turowski
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, New York 14263 United States
| | - Joseph A. Spernyak
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, New York 14263 United States
| | - Janet R. Morrow
- Department of Chemistry, University at Buffalo, State University of New York, Amherst, New York 14260, United States
| |
Collapse
|
6
|
Wong KH, Cheung WM, Pham HL, So YM, Sung HHY, Williams ID, Leung WH. Oxidizing Cerium(IV) Alkoxide Complexes Supported by the Kläui Ligand [Co(η 5-C 5H 5){P(O)(OEt) 2} 3] -: Synthesis, Structure, and Redox Reactivity. Inorg Chem 2021; 60:2261-2270. [PMID: 33499604 DOI: 10.1021/acs.inorgchem.0c03105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tetravalent cerium alkoxide complexes supported by the Kläui tripodal ligand [Co(η5-C5H5){P(O)(OEt)2}3]- (LOEt-) have been synthesized, and their nucleophilic and redox reactivity have been studied. Treatment of the Ce(IV) oxo complex [CeIV(LOEt)2(O)(H2O)]·MeCONH2 (1) with iPrOH or reaction of [CeIV(LOEt)2Cl2] (2) with Ag2O in iPrOH afforded the Ce(IV) dialkoxide complex [CeIV(LOEt)2(OiPr)2] (3-iPr). The methoxide and ethoxide analogues [CeIV(LOEt)2(OR)2] (R = Me (3-Me), Et (3-Et)) have been prepared similarly from 2 and Ag2O in ROH. Reaction of 3-iPr with an equimolar amount of 2 yielded a new Ce(IV) complex that was formulated as the chloro-alkoxide complex [CeIV(LOEt)2(OiPr)Cl] (4). Treatment of 3-iPr with HX and methyl triflate (MeOTf) afforded [Ce(LOEt)2X2] (X- = Cl-, NO3-, PhO-) and [CeIV(LOEt)2(OTf)2], respectively, whereas treatment with excess CO2 in hexane led to isolation of the Ce(IV) carbonate [CeIV(LOEt)2(CO3)]. 3-iPr reacted with water in hexane to give a Ce(III) complex and a Ce(IV) species, presumably the reported tetranuclear oxo cluster [CeIV4(LOEt)4(O)5(OH)2]. The Ce(IV) alkoxide complexes are capable of oxidizing substituted phenols, possibly via a proton-coupled electron transfer pathway. Treatment of 3-iPr with ArOH afforded the Ce(III) aryloxide complexes [CeIII(LOEt)2(OAr)] (Ar = 2,4,6-tri-tert-butylphenyl (5), 2,6-diphenylphenyl (6)). On the other hand, a Ce(III) complex containing a monodeprotonated 2,2'-biphenol ligand, [CeIII(LOEt)2(tBu4C12H4O2H)] (7) (tBu4C12H4O2H2 = 4,4',6,6'-tetra-tert-butyl-2,2'-biphenol), was isolated from the reaction of 3-iPr with 2,4-di-tert-butylphenol. The crystal structures of complexes 3-iPr, 3-Me, 3-Et, and 5-7 have been determined.
Collapse
Affiliation(s)
- Kai-Hong Wong
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Wai-Man Cheung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Hoang-Long Pham
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Yat-Ming So
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Herman H-Y Sung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Ian D Williams
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Wa-Hung Leung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| |
Collapse
|
7
|
Sankaralingam M, Lee YM, Karmalkar DG, Nam W, Fukuzumi S. A Mononuclear Non-heme Manganese(III)–Aqua Complex as a New Active Oxidant in Hydrogen Atom Transfer Reactions. J Am Chem Soc 2018; 140:12695-12699. [DOI: 10.1021/jacs.8b07772] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Deepika G. Karmalkar
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- Faculty of Science and Engineering, Meijo University, Nagoya, Aichi 468-8502, Japan
| |
Collapse
|
8
|
Johnson MS, Horton CL, Gonawala S, Verani CN, Metzger RM. Observation of current rectification by a new asymmetric iron(iii) surfactant in a eutectic GaIn|LB monolayer|Au sandwich. Dalton Trans 2018; 47:6344-6350. [PMID: 29633775 DOI: 10.1039/c8dt00562a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In this paper we expand on the search for molecular rectifiers of electrical current and report on a hexacoordinate metallosurfactant [FeIII(LN3O)(OMe)2], where (LN3O)- is the deprotonated form of the new asymmetric ligand 2-((E)-((4,5-bis(2-methoxyethoxy)-2-(((E)-pyridin-2-ylmethylene)amino)phenyl)imino)methyl)-4,6-di-tert-butyl-phenol. This species rectifies current when deposited as a Langmuir-Blodget film in a "EGaIn/Ga2O3|LB|Au" sandwich with rectification ratios ranging from 25 to 300 at 1 Volt.
Collapse
Affiliation(s)
- Marcus S Johnson
- Laboratory for Molecular Electronics, Department of Chemistry and Biochemistry, University of Alabama, Box 870336, Tuscaloosa, AL 35487, USA.
| | | | | | | | | |
Collapse
|
9
|
Affiliation(s)
- Paolo Pirovano
- School of Chemistry and CRANN/AMBER Nanoscience Institute; Trinity College Dublin; The University of Dublin; College Green 2 Dublin Ireland
| | - Aidan R. McDonald
- School of Chemistry and CRANN/AMBER Nanoscience Institute; Trinity College Dublin; The University of Dublin; College Green 2 Dublin Ireland
| |
Collapse
|
10
|
Chang KC, Huang CJ, Chang YH, Wu ZH, Kuo TS, Hsu HF. Reactivity of a Fe(III)-Bound Methoxide Supported with a Tris(thiolato)phosphine Ligand: Activation of C-Cl Bond in CH2Cl2 by Nucleophilic Attack of a Fe(III)-OCH3 Moiety. Inorg Chem 2015; 55:566-72. [PMID: 26699874 DOI: 10.1021/acs.inorgchem.5b02135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two mononuclear nonheme Fe(III) complexes, [PPh4][Fe(III)(PS3″)(OCH3)] (1) and [PPh4][Fe(III)(PS3″)(Cl)] (2), supported by a tris(benzenethiolato)phosphine derivative PS3″ (PS3″ = P(C6H3-3-Me3Si-2-S)3(3-)) have been synthesized and characterized. The structures resolved from X-ray crystallography show that Fe(III) centers in both complexes adopt distorted trigonal-bipyramidal geometry with a methoxide or a chloride binding in the axial position. The magnetic data for both are consistent with intermediate-spin Fe(III) centers with a C3 symmetry (S = 3/2 ground state). The bound methoxide in 1 is labile and can be replaced by a CH3CN molecule. The forming Fe(III)-CH3CN species can be further reduced by cobaltcene quantitatively to a stable Fe(II)-CH3CN complex, [Fe(PS3″)(CH3CN)](-). One-electron oxidation of 2 by ferrocenium gave a Fe(IV) analogue, [Fe(IV)(PS3″)(Cl)]. Importantly, the Fe(III)-OCH3 moiety in complex 1 acts as a strong nucleophile that activates the C-Cl bond in CH2Cl2, leading to the formation of complex 2 quantitatively. Complex 1 also reacts with other electrophiles, benzyl chloride and benzyl bromide, to generate Fe(III)-X species (X = Cl or Br). The reactions were investigated and monitored by UV-vis-NIR, NMR, and ESI-MS spectroscopies.
Collapse
Affiliation(s)
- Kai-Chun Chang
- Department of Chemistry, National Cheng Kung University , Tainan 701, Taiwan
| | - Ching-Ju Huang
- Department of Chemistry, National Cheng Kung University , Tainan 701, Taiwan
| | - Ya-Ho Chang
- Department of Chemistry, National Cheng Kung University , Tainan 701, Taiwan
| | - Zong-Han Wu
- Department of Chemistry, National Cheng Kung University , Tainan 701, Taiwan
| | - Ting-Shen Kuo
- Department of Chemistry, National Taiwan Normal University , Taipei 116, Taiwan
| | - Hua-Fen Hsu
- Department of Chemistry, National Cheng Kung University , Tainan 701, Taiwan
| |
Collapse
|