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Buratto WR, Ferreira RB, Catalano VJ, García-Serres R, Murray LJ. Cleavage of cluster iron-sulfide bonds in cyclophane-coordinated Fe nS m complexes. Dalton Trans 2021; 50:816-821. [PMID: 33393563 PMCID: PMC7880558 DOI: 10.1039/d0dt03805a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Reaction of the tri(μ-sulfido)triiron(iii) tris(β-diketiminate) cyclophane complex, Fe3S3LEt/Me (1), or of the di(μ-sulfido)diiron(iii) complex Fe2S2HLEt/Me (5), with the related tri(bromide)triiron(ii) complex Fe3Br3LEt/Me (2) results in electron and ligand redistribution to yield the mixed-ligand multiiron complexes, including Fe3Br2SLEt/Me (3) and Fe2Br2SHLEt/Me (4). The cleavage and redistribution observed in these complexes is reminiscent of necessary Fe-S bond cleavage for substrate activation in nitrogenase enzymes, and provides a new perspective on the lability of Fe-S bonds in FeS clusters.
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Affiliation(s)
- William R Buratto
- Department of Chemistry, Center for Catalysis, University of Florida, Gainesville, FL 32611-7200, USA.
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2
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Bhutto SM, Holland PL. Dinitrogen Activation and Functionalization using β-Diketiminate Iron Complexes. Eur J Inorg Chem 2019; 2019:1861-1869. [PMID: 31213945 DOI: 10.1002/ejic.201900133] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Iron catalysts are adept at breaking the N-N bond of N2, as exemplified by the iron-catalyzed Haber-Bosch process and the iron-containing clusters at the active sites of nitrogenase enzymes. This Minireview summarizes recent work that has identified a well-characterized set of multi-iron complexes that are capable of breaking and functionalizing N2, and are amenable to detailed mechanistic studies. We discuss the redox balancing, the potential intermediates during N2 activation, the variation of alkali metal reductant, the reversibility of N2 cleavage, and the formation of N-H and N-C bonds from N2.
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Affiliation(s)
- Samuel M Bhutto
- Department of Chemistry, Yale University, 225 Prospect St, New Haven, CT 06520, USA
| | - Patrick L Holland
- Department of Chemistry, Yale University, 225 Prospect St, New Haven, CT 06520, USA
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3
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Ferreira RB, Cook BJ, Knight BJ, Catalano VJ, García-Serres R, Murray LJ. Catalytic Silylation of Dinitrogen by a Family of Triiron Complexes. ACS Catal 2018; 8:7208-7212. [PMID: 30574427 DOI: 10.1021/acscatal.8b02021] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A series of triiron complexes supported by a tris(β-diketiminate)cyclophane (L 3- ) catalyze the reduction of dinitrogen to tris(trimethylsilyl)amine using KC8 and Me3SiCl. Employing Fe3Br3 L affords 83 ± 7 equiv. NH4 +/complex after protonolysis, which is a 50% yield based on reducing equivalents. The series of triiron compounds tested evidences the subtle effects of ancillary donors, including halides, hydrides, sulfides, and carbonyl ligands, and metal oxidation state on N(SiMe3)3 yield, and highlight Fe3(μ3-N)L as a common species in product mixtures. These results suggest that ancillary ligands can be abstracted with Lewis acids under reducing conditions.
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Affiliation(s)
- Ricardo B. Ferreira
- Center for Catalysis and Florida Center for Heterocyclic Chemistry, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Brian J. Cook
- Center for Catalysis and Florida Center for Heterocyclic Chemistry, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Brian J. Knight
- Center for Catalysis and Florida Center for Heterocyclic Chemistry, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Vincent J. Catalano
- Department of Chemistry, University of Nevada, Reno, Nevada 89557, United States
| | - Ricardo García-Serres
- Université Grenoble Alpes, CNRS, CEA, BIG, LCBM (UMR 5249), F-38054 Grenoble, France
| | - Leslie J. Murray
- Center for Catalysis and Florida Center for Heterocyclic Chemistry, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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4
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Zhang Y, Mei T, Yang D, Zhang Y, Wang B, Qu J. Synthesis and reactivity of thiolate-bridged multi-iron complexes supported by cyclic (alkyl)(amino)carbene. Dalton Trans 2017; 46:15888-15896. [PMID: 29116275 DOI: 10.1039/c7dt03353b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The combined utilization of Me2-cAAC (Me2-cAAC = :C(CH2)(CMe2)2N-2,6-iPr2C6H3) and thiolates as supporting ligands enables the access of unprecedented carbene coordinated thiolate-bridged diiron(ii) complexes [(Me2-cAAC)Fe(μ-SR)(Br)]2 (R = Me, 3; R = Et, 4). The coordination environment of each tetrahedral iron(ii) center in complexes 3 and 4 is composed of one terminal bromide atom, one carbene carbon atom and two thiolate sulfur atoms, which is similar to the carbide-containing sulfur-rich environment of iron centers in the belt region of the FeMo-cofactor. Interestingly, when NaSCPh3 was chosen as the thiolate ligand, C-S bond homolysis occurred to form a rare [3 : 1] site-differentiated cubane-type cluster [(Me2-cAAC)Fe4S4(Br)3][Me2-cAACH] (5). Furthermore, complexes 3 and 4 exhibit good exchange reactivity toward the azide anion to give novel thiolate-bridged diiron complexes with two azido ligands in a trans arrangement.
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Affiliation(s)
- Yanpeng Zhang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, P. R. China
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5
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Pathak S, Jana B, Mandal M, Mandal V, Ghorai TK. Antimicrobial activity study of a μ3-oxo bridged [Fe3O(PhCO2)6(MeOH)3](NO3)(MeOH)2] cluster. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2017.06.120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Anderton KJ, Ermert DM, Quintero PA, Turvey MW, Fataftah MS, Abboud KA, Meisel MW, Čižmár E, Murray LJ. Correlating Bridging Ligand with Properties of Ligand-Templated [Mn II3X 3] 3+ Clusters (X = Br -, Cl -, H -, MeO -). Inorg Chem 2017; 56:12012-12022. [PMID: 28920698 DOI: 10.1021/acs.inorgchem.7b02004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Polynuclear manganese compounds have garnered interest as mimics and models of the water oxidizing complex (WOC) in photosystem II and as single molecule magnets. Molecular systems in which composition can be correlated to physical phenomena, such as magnetic exchange interactions, remain few primarily because of synthetic limitations. Here, we report the synthesis of a family of trimanganese(II) complexes of the type Mn3X3L (X = Cl-, H-, and MeO-) where L3- is a tris(β-diketiminate) cyclophane. The tri(chloride) complex (2) is structurally similar to the reported tri(bromide) complex (1) with the Mn3X3 core having a ladder-like arrangement of alternating M-X rungs, whereas the tri(μ-hydride) (3) and tri(μ-methoxide) (4) complexes contain planar hexagonal cores. The hydride and methoxide complexes are synthesized in good yield (48% and 56%) starting with the bromide complex employing a metathesis-like strategy. Compounds 2-4 were characterized by combustion analysis, X-ray crystallography, X-band EPR spectroscopy, SQUID magnetometry, and infrared and UV-visible spectroscopy. Magnetic susceptibility measurements indicate that the Mn3 clusters in 2-4 are antiferromagnetically coupled, and the spin ground state of the compounds (S = 3/2 (1, 2) or S = 1/2 (3, 4)) is correlated to the identity of the bridging ligand and structural arrangement of the Mn3X3 core (X = Br, Cl, H, OCH3). Electrochemical experiments on isobutyronitrile solutions of 3 and 4 display broad irreversible oxidations centered at 0.30 V.
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Affiliation(s)
- Kevin J Anderton
- Department of Chemistry, Center for Catalysis and Center for Heterocyclic Compounds, University of Florida , Gainesville, Florida 32611, United States
| | - David M Ermert
- Department of Chemistry, Center for Catalysis and Center for Heterocyclic Compounds, University of Florida , Gainesville, Florida 32611, United States
| | - Pedro A Quintero
- Department of Physics and the National High Magnetic Field Laboratory, University of Florida , Gainesville, Florida 32611, United States
| | - Mackenzie W Turvey
- Department of Physics and the National High Magnetic Field Laboratory, University of Florida , Gainesville, Florida 32611, United States
| | - Majed S Fataftah
- Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States
| | - Khalil A Abboud
- Department of Chemistry, Center for Catalysis and Center for Heterocyclic Compounds, University of Florida , Gainesville, Florida 32611, United States
| | - Mark W Meisel
- Department of Physics and the National High Magnetic Field Laboratory, University of Florida , Gainesville, Florida 32611, United States
| | - Erik Čižmár
- Institute of Physics, Faculty of Science, Pavol Jozef Šafárik University , 04154 Košice, Slovakia
| | - Leslie J Murray
- Department of Chemistry, Center for Catalysis and Center for Heterocyclic Compounds, University of Florida , Gainesville, Florida 32611, United States
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Anderton KJ, Knight BJ, Rheingold AL, Abboud KA, García-Serres R, Murray LJ. Reactivity of hydride bridges in a high-spin [Fe 3(μ-H) 3] 3+ cluster: reversible H 2/CO exchange and Fe-H/B-F bond metathesis. Chem Sci 2017; 8:4123-4129. [PMID: 28603601 PMCID: PMC5443887 DOI: 10.1039/c6sc05583d] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/27/2017] [Indexed: 01/08/2023] Open
Abstract
The triiron trihydride complex Fe3H3L (1) [where L3– is a tris(β-diketiminate)cyclophanate] reacts with CO and with BF3·OEt2 to afford (FeICO)2FeII(μ3-H)L (2) and Fe3F3L (3), respectively.
The triiron trihydride complex Fe3H3L (1) [where L3– is a tris(β-diketiminate)cyclophanate] reacts with CO and with BF3·OEt2 to afford (FeICO)2FeII(μ3-H)L (2) and Fe3F3L (3), respectively. Variable-temperature and applied-field Mössbauer spectroscopy support the assignment of two high-spin (HS) iron(i) centers and one HS iron(ii) ion in 2. Preliminary studies support a CO-induced reductive elimination of H2 from 1, rather than CO trapping a species from an equilibrium mixture. This complex reacts with H2 to regenerate 1 under a dihydrogen atmosphere, which represents a rare example of reversible CO/H2 exchange and the first to occur at high-spin metal centers, as well as the first example of a reversible multielectron redox reaction at a designed high-spin metal cluster. The formation of 3 proceeds through a previously unreported net fluoride-for-hydride substitution, and 3 is surprisingly chemically inert to Si–H bonds and points to an unexpectedly large difference between the Fe–F and Fe–H bonds in this high-spin system.
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Affiliation(s)
- Kevin J Anderton
- Center for Catalysis , University of Florida , 214 Leigh Hall P.O. Box 117200 , Gainesville , FL 32611 , USA .
| | - Brian J Knight
- Center for Catalysis , University of Florida , 214 Leigh Hall P.O. Box 117200 , Gainesville , FL 32611 , USA .
| | - Arnold L Rheingold
- Department of Chemistry and Biochemistry , University of California San Diego , 9500 Gilman Drive, MC 0358 , La Jolla , CA 92093-0358 , USA
| | - Khalil A Abboud
- Department of Chemistry , University of Florida , 214 Leigh Hall P.O. Box 117200 , Gainesville , FL 32611 , USA
| | - Ricardo García-Serres
- Laboratoire de Chimie de Biologie des Métaux , UMR 5249 , Université Joseph Fourier , Grenoble-1, CNRS-CEA 17 Rue des Martyrs , 38054 Grenoble Cedex 9 , France
| | - Leslie J Murray
- Center for Catalysis , University of Florida , 214 Leigh Hall P.O. Box 117200 , Gainesville , FL 32611 , USA .
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Ermert DM, Gordon JB, Abboud KA, Murray LJ. Synthesis of Trinuclear Tin(II), Germanium(II), and Aluminum(III) Cyclophane Complexes. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00354] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David M. Ermert
- Center
for Catalysis, Department
of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Jesse B. Gordon
- Center
for Catalysis, Department
of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Khalil A. Abboud
- Center
for Catalysis, Department
of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Leslie J. Murray
- Center
for Catalysis, Department
of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
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