1
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Yamauchi Y, Hoshimoto Y, Kawakita T, Kinoshita T, Uetake Y, Sakurai H, Ogoshi S. Room-Temperature Reversible Chemisorption of Carbon Monoxide on Nickel(0) Complexes. J Am Chem Soc 2022; 144:8818-8826. [PMID: 35504015 PMCID: PMC9348812 DOI: 10.1021/jacs.2c02870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Chemisorption
on organometallic-based adsorbents is crucial for
the controlled separation and long-term storage of gaseous molecules.
The formation of covalent bonds between the metal centers in the adsorbents
and the targeted gases affects the desorption efficiency, especially
when the oxidation state of the metal is low. Herein, we report a
pressure-responsive nickel(0)-based system that is able to reversibly
chemisorb carbon monoxide (CO) at room temperature. The use of N-heterocyclic carbene ligands with hemi-labile N-phosphine oxide substituents facilitates both the adsorption
and desorption of CO on nickel(0) via ligand substitution. Ionic liquids
were used as the reaction medium to enhance the desorption rate and
establish a reusable system. These results showcase a way for the
sustainable chemisorption of CO using a zero-valent transition-metal
complex.
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Affiliation(s)
- Yasuhiro Yamauchi
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Yoichi Hoshimoto
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Takahiro Kawakita
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Takuya Kinoshita
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Yuta Uetake
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| | - Hidehiro Sakurai
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| | - Sensuke Ogoshi
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
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2
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Schneider C, Guggolz L, Werncke CG. High-spin carbonyl complexes of iron(I) and cobalt(I). Dalton Trans 2021; 51:179-184. [PMID: 34874371 DOI: 10.1039/d1dt03924e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Metal carbonyl complexes are almost exclusively found in a low-spin state due to the strong-field nature of the CO ligand. Here the characterisation of highly labile three-coordinate metal(I) monocarbonyl complexes of iron and cobalt is presented. Experimental and quantum chemical examinations reveal their high-spin configuration.
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Affiliation(s)
- Christian Schneider
- Chemistry department, Philipps-University Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
| | - Lukas Guggolz
- Chemistry department, Philipps-University Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
| | - C Gunnar Werncke
- Chemistry department, Philipps-University Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.
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3
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Basu D, Gray DL, Woods TJ, Rauchfuss TB, Arrigoni F, Zampella G. Challenges in the Synthesis of Active Site Mimics for [NiFe]-Hydrogenases. Organometallics 2021; 40:3306-3312. [PMID: 37933322 PMCID: PMC10627515 DOI: 10.1021/acs.organomet.1c00412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One of the more active areas in bioorganometallic chemistry is the preparation and reactivity studies of active site mimics of the [NiFe]-hydrogenases. One area of particular recent progress involves reactions that interconvert Ni(μ-X)Fe centers for X = OH, H, CO, as described by Song et al. Such reactions illustrate new ways to access intermediates related to the Ni-R and Ni-SI states of the enzyme. Most models are derivatives of the type (diphosphine)Ni(SR)2Fe(CO)3-n(PR'3)n. In recent work, the methodology has been generalized to include FeII(diphosphine) derivatives of Ni(N2S2), where N2S22- is the tetradentate diamine-dithiolate (CH2N(CH3)CH2CH2S-)2. Indeed, models based on Ni(N2S2) have proven valuable, but these studies also highlight challenges in working with heterobimetallic complexes, specifically the tendency of some such Ni-Fe complexes to convert to homometalliic Ni-Ni derivatives. This kind of problem is not readily detected by X-ray crystallography. With this caution in mind, we argue that one series of complexes recently described in this journal are almost certainly misassigned.
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Affiliation(s)
- Debashis Basu
- School of Chemical Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Danielle L Gray
- School of Chemical Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Toby J Woods
- School of Chemical Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Thomas B Rauchfuss
- School of Chemical Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United State
| | - Federica Arrigoni
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
| | - Giuseppe Zampella
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy
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4
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Britt RD, Rauchfuss TB. Biosynthesis of the [FeFe] hydrogenase H-cluster via a synthetic [Fe(II)(CN)(CO) 2(cysteinate)] - complex. Dalton Trans 2021; 50:12386-12391. [PMID: 34545884 DOI: 10.1039/d1dt02258j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The H-cluster of [Fe-Fe] hydrogenase consists of a [4Fe]H subcluster linked by the sulfur of a cysteine residue to an organometallic [2Fe]H subcluster that utilizes terminal CO and CN ligands to each Fe along with a bridging CO and a bridging SCH2NHCH2S azadithiolate (adt) to catalyze proton reduction or hydrogen oxidation. Three Fe-S "maturase" proteins, HydE, HydF, and HydG, are responsible for the biosynthesis of the [2Fe]H subcluster and its incorporation into the hydrogenase enzyme to form this catalytically active H-cluster. We have proposed that HydG is a bifunctional enzyme that uses S-adenosylmethione (SAM) bound to a [4Fe-4S] cluster to lyse tyrosine via a transient 5'-deoxyadenosyl radical to produce CO and CN ligands to a unique cysteine-chelated Fe(II) that is linked to a second [4Fe-4S] cluster via the cysteine sulfur. In this "synthon model", after two cycles of tyrosine lysis, the product of HydG is completed: a [Fe(CN)(CO)2(cysteinate)]- organometallic unit that is vectored directly into the synthesis of the [2Fe]H sub-cluster. However our HydG-centric synthon model is not universally accepted, so further validation is important. In this Frontiers article, we discuss recent results using a synthetic "Syn-B" complex that donates [Fe(CN)(CO)2(cysteinate)]- units that match our proposed HydG product. Can Syn-B activate hydrogenase in the absence of HydG and its tyrosine substrate? If so, since Syn-B can be synthesized with specific magnetic nuclear isotopes and with chemical substitutions, its use could allow its enzymatic conversions on the route to the H-cluster to be monitored and modeled in fresh detail.
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Affiliation(s)
- R David Britt
- Department of Chemistry, University of California Davis, Davis, CA 95616, USA.
| | - Thomas B Rauchfuss
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
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5
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Takebayashi S, Fayzullin RR. [Co(NHC)(CO) 3]: Isolation and Reactivity Study of a Model 17-Electron Species in the Oxo Process. Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Satoshi Takebayashi
- Science and Technology Group, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Robert R. Fayzullin
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, Kazan 420088, Russian Federation
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6
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Brief survey of diiron and monoiron carbonyl complexes and their potentials as CO-releasing molecules (CORMs). Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2020.213634] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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7
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Sun L, An Y, Ma L, Han Y. Single‐Crystalline Organoiridium Complex for Gas‐Triggered Chromogenic Switches and Its Applications on CO Detection and Reversible Scavenging. CHINESE J CHEM 2019. [DOI: 10.1002/cjoc.201900151] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Li‐Ying Sun
- Key Laboratory of Synthetic and Natural Functional Molecule ChemistryCollege of Chemistry and Materials Science, Northwest University Xi'an Shaaxi 710127 China
| | - Yuan‐Yuan An
- Key Laboratory of Synthetic and Natural Functional Molecule ChemistryCollege of Chemistry and Materials Science, Northwest University Xi'an Shaaxi 710127 China
| | - Li‐Li Ma
- Key Laboratory of Synthetic and Natural Functional Molecule ChemistryCollege of Chemistry and Materials Science, Northwest University Xi'an Shaaxi 710127 China
| | - Ying‐Feng Han
- Key Laboratory of Synthetic and Natural Functional Molecule ChemistryCollege of Chemistry and Materials Science, Northwest University Xi'an Shaaxi 710127 China
- State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences Fuzhou Fujian 350002 China
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8
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Taylor LJ, Kays DL. Low-coordinate first-row transition metal complexes in catalysis and small molecule activation. Dalton Trans 2019; 48:12365-12381. [DOI: 10.1039/c9dt02402f] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this Perspective, we will highlight selected examples of transition metal complexes with low coordination numbers whose high reactivity has been exploited in catalysis and the activation of small molecules featuring strong bonds (N2, CO2, and CO).
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Affiliation(s)
| | - Deborah L. Kays
- School of Chemistry
- University of Nottingham
- University Park
- Nottingham
- UK
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9
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Selective reduction and homologation of carbon monoxide by organometallic iron complexes. Nat Commun 2018; 9:3757. [PMID: 30217985 PMCID: PMC6138626 DOI: 10.1038/s41467-018-06242-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/15/2018] [Indexed: 12/05/2022] Open
Abstract
Carbon monoxide is a key C1 feedstock for the industrial production of hydrocarbons, where it is used to make millions of tonnes of chemicals, fuels, and solvents per annum. Many transition metal complexes can coordinate CO, but the formation of new C−C bonds in well-defined compounds from the scission and subsequent coupling of two or more CO moieties at a transition metal centre remains a challenge. Herein, we report the use of low-coordinate iron(II) complexes for the selective scission and homologation of CO affording unusual squaraines and iron carboxylates at ambient temperature and pressure. A modification of the ligand framework allows for the isolation and structural characterisation of a proposed metallacyclic Fe(II) carbene intermediate. These results indicate that, with the appropriate choice of supporting ligands, it is possible to cleave and homologate carbon monoxide under mild conditions using an abundant and environmentally benign low-coordinate, first row transition metal. Metal-mediated activation of CO for C-C coupling reactions is a valuable approach to carbon monoxide valorization. Here, the authors use low-coordinate iron(II) complexes for the selective scission and homologation of CO affording unusual squaraines and iron carboxylates under mild conditions.
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10
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Arnett CH, Chalkley MJ, Agapie T. A Thermodynamic Model for Redox-Dependent Binding of Carbon Monoxide at Site-Differentiated, High Spin Iron Clusters. J Am Chem Soc 2018; 140:5569-5578. [PMID: 29589921 DOI: 10.1021/jacs.8b01825] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Binding of N2 and CO by the FeMo-cofactor of nitrogenase depends on the redox level of the cluster, but the extent to which pure redox chemistry perturbs the affinity of high spin iron clusters for π-acids is not well understood. Here, we report a series of site-differentiated iron clusters that reversibly bind CO in redox states FeII4 through FeIIFeIII3. One electron redox events result in small changes in the affinity for (at most ∼400-fold) and activation of CO (at most 28 cm-1 for νCO). The small influence of redox chemistry on the affinity of these high spin, valence-localized clusters for CO is in stark contrast to the large enhancements (105-1022 fold) in π-acid affinity reported for monometallic and low spin, bimetallic iron complexes, where redox chemistry occurs exclusively at the ligand binding site. While electron-loading at metal centers remote from the substrate binding site has minimal influence on the CO binding energetics (∼1 kcal·mol-1), it provides a conduit for CO binding at an FeIII center. Indeed, internal electron transfer from these remote sites accommodates binding of CO at an FeIII, with a small energetic penalty arising from redox reorganization (∼2.6 kcal·mol-1). The ease with which these clusters redistribute electrons in response to ligand binding highlights a potential pathway for coordination of N2 and CO by FeMoco, which may occur on an oxidized edge of the cofactor.
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Affiliation(s)
- Charles H Arnett
- Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
| | - Matthew J Chalkley
- Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
| | - Theodor Agapie
- Division of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , California 91125 , United States
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11
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Reed DA, Keitz BK, Oktawiec J, Mason JA, Runčevski T, Xiao DJ, Darago LE, Crocellà V, Bordiga S, Long JR. A spin transition mechanism for cooperative adsorption in metal-organic frameworks. Nature 2017; 550:96-100. [PMID: 28892810 DOI: 10.1038/nature23674] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/24/2017] [Indexed: 01/03/2023]
Abstract
Cooperative binding, whereby an initial binding event facilitates the uptake of additional substrate molecules, is common in biological systems such as haemoglobin. It was recently shown that porous solids that exhibit cooperative binding have substantial energetic benefits over traditional adsorbents, but few guidelines currently exist for the design of such materials. In principle, metal-organic frameworks that contain coordinatively unsaturated metal centres could act as both selective and cooperative adsorbents if guest binding at one site were to trigger an electronic transformation that subsequently altered the binding properties at neighbouring metal sites. Here we illustrate this concept through the selective adsorption of carbon monoxide (CO) in a series of metal-organic frameworks featuring coordinatively unsaturated iron(ii) sites. Functioning via a mechanism by which neighbouring iron(ii) sites undergo a spin-state transition above a threshold CO pressure, these materials exhibit large CO separation capacities with only small changes in temperature. The very low regeneration energies that result may enable more efficient Fischer-Tropsch conversions and extraction of CO from industrial waste feeds, which currently underutilize this versatile carbon synthon. The electronic basis for the cooperative adsorption demonstrated here could provide a general strategy for designing efficient and selective adsorbents suitable for various separations.
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Affiliation(s)
- Douglas A Reed
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Benjamin K Keitz
- Department of Chemistry, University of California, Berkeley, California 94720, USA.,McKetta Department of Chemical Engineering, University of Texas, Austin, Texas 78712, USA
| | - Julia Oktawiec
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Jarad A Mason
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Tomče Runčevski
- Department of Chemistry, University of California, Berkeley, California 94720, USA.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Dianne J Xiao
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Lucy E Darago
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Valentina Crocellà
- Chemistry Department, NIS and INSTM Centre of Reference, University of Turin, Via Quarello 15, I-10135 Torino, Italy
| | - Silvia Bordiga
- Chemistry Department, NIS and INSTM Centre of Reference, University of Turin, Via Quarello 15, I-10135 Torino, Italy
| | - Jeffrey R Long
- Department of Chemistry, University of California, Berkeley, California 94720, USA.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, USA
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12
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Gallagher AT, Malliakas CD, Harris TD. CO Binding at a Four-Coordinate Cobaltous Porphyrin Site in a Metal–Organic Framework: Structural, EPR, and Gas Adsorption Analysis. Inorg Chem 2017; 56:4655-4662. [DOI: 10.1021/acs.inorgchem.7b00292] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Audrey T. Gallagher
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Christos D. Malliakas
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - T. David Harris
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
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13
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Schröder-Holzhacker C, Stöger B, Pittenauer E, Allmaier G, Veiros LF, Kirchner K. High-spin iron(II) complexes with mono-phosphorylated 2,6-diaminopyridine ligands. MONATSHEFTE FUR CHEMIE 2016; 147:1539-1545. [PMID: 27546911 PMCID: PMC4977337 DOI: 10.1007/s00706-016-1731-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/07/2016] [Indexed: 11/29/2022]
Abstract
Abstract Several new monophosphorylated 2,6-diaminopyridine ligands bearing PiPr2 and PtBu2 units (PNNH2-iPr, PNNH2-tBu, PNNHMe-iPr, and PNNHEt-iPr) are prepared by treatment of the respective 2,6-diaminopyridines with the chlorophosphines PiPr2Cl and PtBu2Cl in the presence of a base. Treatment of anhydrous FeCl2 with 1 equiv of these afforded the tetracoordinated coordinatively unsaturated 14e− complexes [Fe(κ2P,N-PNNH2-iPr)Cl2] and [Fe(κ2P,N-PNNH2-tBu)Cl2], while with PNNHMe-iPr and PNNHEt-iPr a phosphine transfer reaction of a second PN ligand took place to yield the known PNP pincer complexes [Fe(κ3P,N,P-PNPMe-iPr)Cl2] and [Fe(κ3P,N,P-PNPEt-iPr)Cl2]. The four-coordinate complexes [Fe(κ2P,N-PNNH2-iPr)Cl2] and [Fe(κ2P,N-PNNH2-tBu)Cl2] did not react with CO and the formation of iron PNC pincer complexes was not observed. The reason for the reluctance to add CO was investigated in detail by DFT calculations. Graphical abstract ![]()
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Affiliation(s)
- Christan Schröder-Holzhacker
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163-OC, 1060 Vienna, Austria
| | - Berthold Stöger
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Ernst Pittenauer
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Günther Allmaier
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Luis F Veiros
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais No. 1, 1049-001 Lisbon, Portugal
| | - Karl Kirchner
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163-OC, 1060 Vienna, Austria
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14
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Reed DA, Xiao DJ, Gonzalez MI, Darago LE, Herm ZR, Grandjean F, Long JR. Reversible CO Scavenging via Adsorbate-Dependent Spin State Transitions in an Iron(II)–Triazolate Metal–Organic Framework. J Am Chem Soc 2016; 138:5594-602. [DOI: 10.1021/jacs.6b00248] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
| | | | | | | | | | - Fernande Grandjean
- Department
of Chemistry, Missouri University of Science and Technology, University of Missouri, Rolla, Missouri 65409, United States
| | - Jeffrey R. Long
- Materials
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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15
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Holzhacker C, Stöger B, Carvalho MD, Ferreira LP, Pittenauer E, Allmaier G, Veiros LF, Realista S, Gil A, Calhorda MJ, Müller D, Kirchner K. Synthesis and reactivity of TADDOL-based chiral Fe(II) PNP pincer complexes-solution equilibria between κ(2)P,N- and κ(3)P,N,P-bound PNP pincer ligands. Dalton Trans 2015; 44:13071-86. [PMID: 26104487 DOI: 10.1039/c5dt00832h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Treatment of anhydrous FeX2 (X = Cl, Br) with 1 equiv. of the asymmetric chiral PNP pincer ligands PNP-R,TAD (R = iPr, tBu) with an R,R-TADDOL (TAD) moiety afforded complexes of the general formula [Fe(PNP)X2]. In the solid state these complexes adopt a tetrahedral geometry with the PNP ligand coordinated in κ(2)P,N-fashion, as shown by X-ray crystallography and Mössbauer spectroscopy. Magnetization studies led to a magnetic moment very close to 4.9μB reflecting the expected four unpaired d-electrons (quintet ground state). In solution there are equilibria between [Fe(κ(3)P,N,P-PNP-R,TAD)X2] and [Fe(κ(2)P,N-PNP-R,TAD)X2] complexes, i.e., the PNP-R,TAD ligand is hemilabile. At -50 °C these equilibria are slow and signals of the non-coordinated P-TAD arm of the κ(2)P,N-PNP-R,TAD ligand can be detected by (31)P{(1)H} NMR spectroscopy. Addition of BH3 to a solution of [Fe(PNP-iPr,TAD)Cl2] leads to selective boronation of the pendant P-TAD arm shifting the equilibrium towards the four-coordinate complex [Fe(κ(2)P,N-PNP-iPr,TAD(BH3))Cl2]. DFT calculations corroborate the existence of equilibria between four- and five-coordinated complexes. Addition of CO to [Fe(PNP-iPr,TAD)X2] in solution yields the diamagnetic octahedral complexes trans-[Fe(κ(3)P,N,P-PNP-iPr,TAD)(CO)X2], which react further with Ag(+) salts in the presence of CO to give the cationic complexes trans-[Fe(κ(3)P,N,P-PNP-iPr,TAD)(CO)2X](+). CO addition most likely takes place at the five coordinate complex [Fe(κ(3)P,N,P-PNP-iPr,TAD)X2]. The mechanism for the CO addition was also investigated by DFT and the most favorable path obtained corresponds to the rearrangement of the pincer ligand first from a κ(2)P,N- to a κ(3)P,N,P-coordination mode followed by CO coordination to [Fe(κ(3)P,N,P-PNP-iPr,TAD)X2]. Complexes bearing tBu substituents do not react with CO. Moreover, in the solid state none of the tetrahedral complexes are able to bind CO.
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Affiliation(s)
- Christian Holzhacker
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria.
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16
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Knut R, Lagerqvist U, Palmgren P, Pal P, Svedlindh P, Pohl A, Karis O. Photoinduced reduction of surface states in Fe:ZnO. J Chem Phys 2015; 142:204703. [DOI: 10.1063/1.4921570] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- R. Knut
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - U. Lagerqvist
- Department of Chemistry Ångström, Uppsala University, P.O. Box 538, SE-751 21 Uppsala, Sweden
| | - P. Palmgren
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - P. Pal
- MAX-Laboratory, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012, India
| | - P. Svedlindh
- Department of Engineering Sciences, Uppsala University, P.O. Box 534, SE-75121 Uppsala, Sweden
| | - A. Pohl
- Department of Chemistry Ångström, Uppsala University, P.O. Box 538, SE-751 21 Uppsala, Sweden
| | - O. Karis
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
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17
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Gilbert-Wilson R, Chu WY, Rauchfuss TB. Phosphine-iminopyridines as platforms for catalytic hydrofunctionalization of alkenes. Inorg Chem 2015; 54:5596-603. [PMID: 25978588 DOI: 10.1021/acs.inorgchem.5b00692] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of phosphine-diimine ligands were synthesized by the condensation of 2-(diphenylphosphino)aniline (PNH2) with a variety of formyl and ketopyridines. Condensation of PNH2 with acetyl- and benzoylpyridine yielded the Ph2P(C6H4)N═C(R)(C5H4N), respectively abbreviated PN(Me)py and PN(Ph)py. With ferrous halides, PN(Ph)py gave the complexes FeX2(PN(Ph)py) (X = Cl, Br). Condensation of pyridine carboxaldehyde and its 6-methyl derivatives with PNH2 was achieved using a ferrous template, affording low-spin complexes [Fe(PN(H)py(R))2](2+) (R = H, Me). Dicarbonyls Fe(PN(R)py)(CO)2 were produced by treating PN(Me)py with Fe(benzylideneacetone)(CO)3 and reduction of FeX2(PN(Ph)py) with NaBEt3H under a CO atmosphere. Cyclic voltammetric studies show that the [FeL3(CO)2](0/-) and [FeL3(CO)2](+/0) couples are similar for a range of tridentate ligands, but the PN(Ph)py system uniquely sustains two one-electron reductions. Treatment of Fe(PN(Ph)py)X2 with NaBEt3H gave active catalysts for the hydroboration of 1-octene with pinacolborane. Similarly, these catalysts proved active for the addition of diphenylsilane, but not HSiMe(OSiMe3)2, to 1-octene and vinylsilanes. Evidence is presented that catalysis occurs via iron hydride complexes of intact PN(Ph)py.
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Affiliation(s)
- Ryan Gilbert-Wilson
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Wan-Yi Chu
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Thomas B Rauchfuss
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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18
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Beck R, Camadanli S, Flörke U, Klein HF. Reactivity Diversification - Synthesis and Exchange Reactions of Cobalt and Iron 2-Alkenylpyridine/-pyrazine Complexes Obtained by Vinylic C(sp2)-H Activation. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201500225] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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19
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Ling L, Liu K, Li X, Li Y. General Reaction Mode of Hypervalent Iodine Trifluoromethylation Reagent: A Density Functional Theory Study. ACS Catal 2015. [DOI: 10.1021/cs501892s] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Lin Ling
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
| | - Kun Liu
- College
of Chemistry, Tianjin Normal University, Tianjin 300387, P. R. China
| | - Xinqian Li
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
| | - Yuxue Li
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, P. R. China
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20
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Wang B, Zhou X, Wang D, Yin JJ, Chen H, Gao X, Zhang J, Ibrahim K, Chai Z, Feng W, Zhao Y. Structure and catalytic activities of ferrous centers confined on the interface between carbon nanotubes and humic acid. NANOSCALE 2015; 7:2651-2658. [PMID: 25580558 DOI: 10.1039/c4nr06665k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Preparation of heterogeneous catalysts with active ferrous centers is of great significance for industrial and environmental catalytic processes. Nanostructured carbon materials (NCM), which possess free-flowing π electrons, can coordinate with transition metals, provide a confinement environment for catalysis, and act as potential supports or ligands to construct analogous complexes. However, designing such catalysts using NCM is still seldom studied to date. Herein, we synthesized a sandwich structured ternary complex via the coordination of Fe-loaded humic acid (HA) with C=C bonds in the aromatic rings of carbon nanotubes (CNTs), in which the O/N-Fe-C interface configuration provides the confinement environment for the ferrous sites. The experimental and theoretical results revealed octahedrally/tetrahedrally coordinated geometry at Fe centers, and the strong hybridization between CNT C π* and Fe 3d orbitals induces discretization of the atomic charges on aromatic rings of CNTs, which facilitates O2 adsorption and electron transfer from carbon to O2, which enhances O2 activation. The O2 activation by the novel HA/Fe-CNT complex can be applied in the oxidative degradation of phenol red (PR) and bisphenol A (BPA) in aqueous media.
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Affiliation(s)
- Bing Wang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
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21
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Chu WY, Zhou X, Rauchfuss TB. Cooperative Metal–Ligand Reactivity and Catalysis in Low-Spin Ferrous Alkoxides. Organometallics 2015. [DOI: 10.1021/om501152h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Wan-Yi Chu
- School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801, United States
| | - Xiaoyuan Zhou
- School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801, United States
| | - Thomas B. Rauchfuss
- School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801, United States
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22
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Bhattacharya P, Krause JA, Guan H. Activation of Dihydrogen and Silanes by Cationic Iron Bis(phosphinite) Pincer Complexes. Organometallics 2014. [DOI: 10.1021/om500758j] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Papri Bhattacharya
- Department
of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States
| | - Jeanette A. Krause
- Department
of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States
| | - Hairong Guan
- Department
of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States
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23
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Bloch ED, Hudson MR, Mason JA, Chavan S, Crocellà V, Howe JD, Lee K, Dzubak AL, Queen WL, Zadrozny JM, Geier SJ, Lin LC, Gagliardi L, Smit B, Neaton JB, Bordiga S, Brown CM, Long JR. Reversible CO binding enables tunable CO/H₂ and CO/N₂ separations in metal-organic frameworks with exposed divalent metal cations. J Am Chem Soc 2014; 136:10752-61. [PMID: 24999916 DOI: 10.1021/ja505318p] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Six metal-organic frameworks of the M2(dobdc) (M = Mg, Mn, Fe, Co, Ni, Zn; dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate) structure type are demonstrated to bind carbon monoxide reversibly and at high capacity. Infrared spectra indicate that, upon coordination of CO to the divalent metal cations lining the pores within these frameworks, the C-O stretching frequency is blue-shifted, consistent with nonclassical metal-CO interactions. Structure determinations reveal M-CO distances ranging from 2.09(2) Å for M = Ni to 2.49(1) Å for M = Zn and M-C-O angles ranging from 161.2(7)° for M = Mg to 176.9(6)° for M = Fe. Electronic structure calculations employing density functional theory (DFT) resulted in good agreement with the trends apparent in the infrared spectra and crystal structures. These results represent the first crystallographically characterized magnesium and zinc carbonyl compounds and the first high-spin manganese(II), iron(II), cobalt(II), and nickel(II) carbonyl species. Adsorption isotherms indicate reversible adsorption, with capacities for the Fe, Co, and Ni frameworks approaching one CO per metal cation site at 1 bar, corresponding to loadings as high as 6.0 mmol/g and 157 cm(3)/cm(3). The six frameworks display (negative) isosteric heats of CO adsorption ranging from 52.7 to 27.2 kJ/mol along the series Ni > Co > Fe > Mg > Mn > Zn, following the Irving-Williams stability order. The reversible CO binding suggests that these frameworks may be of utility for the separation of CO from various industrial gas mixtures, including CO/H2 and CO/N2. Selectivities determined from gas adsorption isotherm data using ideal adsorbed solution theory (IAST) over a range of gas compositions at 1 bar and 298 K indicate that all six M2(dobdc) frameworks could potentially be used as solid adsorbents to replace current cryogenic distillation technologies, with the choice of M dictating adsorbent regeneration energy and the level of purity of the resulting gases.
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Affiliation(s)
- Eric D Bloch
- Department of Chemistry, University of California , Berkeley, California 94720, United States
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24
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Carroll M, Chen J, Gray DE, Lansing JC, Rauchfuss TB, Schilter D, Volkers PI, Wilson S. Ferrous Carbonyl Dithiolates as Precursors to FeFe, FeCo, and FeMn Carbonyl Dithiolates. Organometallics 2014; 33:858-867. [PMID: 24803716 PMCID: PMC3999794 DOI: 10.1021/om400752a] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Indexed: 01/23/2023]
Abstract
Reported are complexes of the formula Fe(dithiolate)(CO)2(diphos) and their use to prepare homo- and heterobimetallic dithiolato derivatives. The starting iron dithiolates were prepared by a one-pot reaction of FeCl2 and CO with chelating diphosphines and dithiolates, where dithiolate = S2(CH2)22- (edt2-), S2(CH2)32- (pdt2-), S2(CH2)2(C(CH3)2)2- (Me2pdt2-) and diphos = cis-C2H2(PPh2)2 (dppv), C2H4(PPh2)2 (dppe), C6H4(PPh2)2 (dppbz), C2H4[P(C6H11)2]2 (dcpe). The incorporation of 57Fe into such building block complexes commenced with the conversion of 57Fe into 57Fe2I4( i PrOH)4, which then was treated with K2pdt, CO, and dppe to give 57Fe(pdt)(CO)2(dppe). NMR and IR analyses show that these complexes exist as mixtures of all-cis and trans-CO isomers, edt2- favoring the former and pdt2- the latter. Treatment of Fe(dithiolate)(CO)2(diphos) with the Fe(0) reagent (benzylideneacetone)Fe(CO)3 gave Fe2(dithiolate)(CO)4(diphos), thereby defining a route from simple ferrous salts to models for hydrogenase active sites. Extending the building block route to heterobimetallic complexes, treatment of Fe(pdt)(CO)2(dppe) with [(acenaphthene)Mn(CO)3]+ gave [(CO)3Mn(pdt)Fe(CO)2(dppe)]+ ([3d(CO)]+). Reduction of [3d(CO)]+ with BH4- gave the Cs -symmetric μ-hydride (CO)3Mn(pdt)(H)Fe(CO)(dppe) (H3d). Complex H3d is reversibly protonated by strong acids, the proposed site of protonation being sulfur. Treatment of Fe(dithiolate)(CO)2(diphos) with CpCoI2(CO) followed by reduction by Cp2Co affords CpCo(dithiolate)Fe(CO)(diphos) (4), which can also be prepared from Fe(dithiolate)(CO)2(diphos) and CpCo(CO)2. Like the electronically related (CO)3Fe(pdt)Fe(CO)(diphos), these complexes undergo protonation to afford the μ-hydrido complexes [CpCo(dithiolate)HFe(CO)(diphos)]+. Low-temperature NMR studies indicate that Co is the kinetic site of protonation.
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Affiliation(s)
- Maria
E. Carroll
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Jinzhu Chen
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Danielle E. Gray
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - James C. Lansing
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Thomas B. Rauchfuss
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - David Schilter
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Phillip I. Volkers
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Scott
R. Wilson
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
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25
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Bellows SM, Cundari TR, Holland PL. Spin Crossover during β-Hydride Elimination in High-Spin Iron(II)– and Cobalt(II)–Alkyl Complexes. Organometallics 2013. [DOI: 10.1021/om400325x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Sarina M. Bellows
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Thomas R. Cundari
- Department of Chemistry and CaSCAM, University of North Texas, Denton, Texas 76203, United States
| | - Patrick L. Holland
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
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26
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Zell T, Langer R, Iron MA, Konstantinovski L, Shimon LJW, Diskin-Posner Y, Leitus G, Balaraman E, Ben-David Y, Milstein D. Synthesis, Structures, and Dearomatization by Deprotonation of Iron Complexes Featuring Bipyridine-based PNN Pincer Ligands. Inorg Chem 2013; 52:9636-49. [DOI: 10.1021/ic401432m] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Thomas Zell
- Department of Organic Chemistry and ‡Department of
Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Robert Langer
- Department of Organic Chemistry and ‡Department of
Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Mark A. Iron
- Department of Organic Chemistry and ‡Department of
Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Leonid Konstantinovski
- Department of Organic Chemistry and ‡Department of
Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Linda J. W. Shimon
- Department of Organic Chemistry and ‡Department of
Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Yael Diskin-Posner
- Department of Organic Chemistry and ‡Department of
Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Gregory Leitus
- Department of Organic Chemistry and ‡Department of
Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Ekambaram Balaraman
- Department of Organic Chemistry and ‡Department of
Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Yehoshoa Ben-David
- Department of Organic Chemistry and ‡Department of
Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - David Milstein
- Department of Organic Chemistry and ‡Department of
Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel
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27
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Weber C, O'Regan DD, Hine NDM, Littlewood PB, Kotliar G, Payne MC. Importance of many-body effects in the Kernel of hemoglobin for ligand binding. PHYSICAL REVIEW LETTERS 2013; 110:106402. [PMID: 23521275 DOI: 10.1103/physrevlett.110.106402] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 11/14/2012] [Indexed: 06/01/2023]
Abstract
We propose a mechanism for binding of diatomic ligands to heme based on a dynamical orbital selection process. This scenario may be described as bonding determined by local valence fluctuations. We support this model using linear-scaling first-principles calculations, in combination with dynamical mean-field theory, applied to heme, the kernel of the hemoglobin metalloprotein central to human respiration. We find that variations in Hund's exchange coupling induce a reduction of the iron 3d density, with a concomitant increase of valence fluctuations. We discuss the comparison between our computed optical absorption spectra and experimental data, our picture accounting for the observation of optical transitions in the infrared regime, and how the Hund's coupling reduces, by a factor of 5, the strong imbalance in the binding energies of heme with CO and O(2) ligands.
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Affiliation(s)
- Cédric Weber
- King's College London, Theory and Simulation of Condensed Matter, The Strand, London WC2R 2LS, United Kingdom
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28
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Holzhacker C, Standfest-Hauser CM, Puchberger M, Mereiter K, Veiros LF, Calhorda MJ, Carvalho MD, Ferreira LP, Godinho M, Hartl F, Kirchner K. Reversible Addition of CO to Coordinatively Unsaturated High-Spin Iron(II) Complexes. Organometallics 2011. [DOI: 10.1021/om200711q] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | - Luis F. Veiros
- Centro de Quı́mica Estrutural,
Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa, Portugal
| | | | | | - Liliana P. Ferreira
- Departamento Fı́sica,
Faculdade Ciências e Tecnologia, Universidade de Coimbra, 3004-516 Coimbra, Portugal
| | | | - František Hartl
- Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD,
United Kingdom
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29
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Carroll ME, Barton BE, Gray DL, Mack AE, Rauchfuss TB. Active-site models for the nickel-iron hydrogenases: effects of ligands on reactivity and catalytic properties. Inorg Chem 2011; 50:9554-63. [PMID: 21866886 DOI: 10.1021/ic2012759] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Described are new derivatives of the type [HNiFe(SR)(2)(diphosphine)(CO)(3)](+), which feature a Ni(diphosphine) group linked to a Fe(CO)(3) group by two bridging thiolate ligands. Previous work had described [HNiFe(pdt)(dppe)(CO)(3)](+) ([1H](+)) and its activity as a catalyst for the reduction of protons (J. Am. Chem. Soc. 2010, 132, 14877). Work described in this paper focuses on the effects on properties of NiFe model complexes of the diphosphine attached to nickel as well as the dithiolate bridge, 1,3-propanedithiolate (pdt) vs 1,2-ethanedithiolate (edt). A new synthetic route to these Ni-Fe dithiolates is described, involving reaction of Ni(SR)(2)(diphosphine) with FeI(2)(CO)(4) followed by in situ reduction with cobaltocene. Evidence is presented that this route proceeds via a metastable μ-iodo derivative. Attempted isolation of such species led to the crystallization of NiFe(Me(2)pdt)(dppe)I(2), which features tetrahedral Fe(II) and square planar Ni(II) centers (H(2)Me(2)pdt = 2,2-dimethylpropanedithiol). The new tricarbonyls prepared in this work are NiFe(pdt)(dcpe)(CO)(3) (2, dcpe = 1,2-bis(dicyclohexylphosphino)ethane), NiFe(edt)(dppe)(CO)(3) (3), and NiFe(edt)(dcpe)(CO)(3) (4). Attempted preparation of a phenylthiolate-bridged complex via the FeI(2)(CO)(4) + Ni(SPh)(2)(dppe) route gave the tetrametallic species [(CO)(2)Fe(SPh)(2)Ni(CO)](2)(μ-dppe)(2). Crystallographic analysis of the edt-dcpe compund [2H]BF(4) and the edt-dppe compound [3H]BF(4) verified their close resemblance. Each features pseudo-octahedral Fe and square pyramidal Ni centers. Starting from [3H]BF(4) we prepared the PPh(3) derivative [HNiFe(edt)(dppe)(PPh(3))(CO)(2)]BF(4) ([5H]BF(4)), which was obtained as a ∼2:1 mixture of unsymmetrical and symmetrical isomers. Acid-base measurements indicate that changing from Ni(dppe) (dppe = Ph(2)PCH(2)CH(2)PPh(2)) to Ni(dcpe) decreases the acidity of the cationic hydride complexes by 2.5 pK(a)(PhCN) units, from ∼11 to ∼13.5 (previous work showed that substitution at Fe leads to more dramatic effects). The redox potentials are more strongly affected by the change from dppe to dcpe, for example the [2](0/+) couple occurs at E(1/2) = -820 for [2](0/+) vs -574 mV (vs Fc(+/0)) for [1](0/+). Changes in the dithiolate do not affect the acidity or the reduction potentials of the hydrides. The acid-independent rate of reduction of CH(2)ClCO(2)H by [2H](+) is about 50 s(-1) (25 °C), twice that of [1H](+). The edt-dppe complex [2H](+) proved to be the most active catalyst, with an acid-independent rate of 300 s(-1).
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Affiliation(s)
- Maria E Carroll
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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30
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Zenkina OV, Keske EC, Wang R, Crudden CM. Double Single-Crystal-to-Single-Crystal Transformation and Small-Molecule Activation in Rhodium NHC Complexes. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201103316] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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31
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Zenkina OV, Keske EC, Wang R, Crudden CM. Double single-crystal-to-single-crystal transformation and small-molecule activation in rhodium NHC complexes. Angew Chem Int Ed Engl 2011; 50:8100-4. [PMID: 21744453 DOI: 10.1002/anie.201103316] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2011] [Indexed: 11/05/2022]
Abstract
Three gases, one crystal: rhodium NHC complexes undergo back-to-back single-crystal-to-single-crystal transformations by selective nonreversible ligand exchange reactions. Slow diffusion of O(2) converts a dinitrogen complex into a dioxygen complex, and CO subsequently replaces O(2).
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Affiliation(s)
- Olena V Zenkina
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada
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