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Matsubara K, Yamada Y, Iwasaki H, Ikeda H, Kanetsugu Y, Kawata S, Koga Y. A 1,2,3-triazole-derived pincer-type mesoionic carbene complex of iron(II): carbonyl elimination and hydrosilylation of aromatic aldehydes via the concerted reaction with hydrosilane and a base. Dalton Trans 2023; 52:572-582. [PMID: 36537300 DOI: 10.1039/d2dt03617g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Iron complexes bearing 1,2,3-triazol-5-ylidene were synthesized and applied to the reaction with hydrosilane and homogeneous catalytic hydrosilylation of aromatic ketones and aldehydes. Addition of a free carbene to a solution of Fe(CO)4Br2 yielded an octahedral, diamagnetic and cationic iron(II) complex [Fe(1,2,3-triazolylidene)(CO)2Br]+. Pyrolysis of the dicarbonyl complex eliminated the two CO ligands to form a paramagnetic four-coordinate complex. A theoretical study using DFT calculations indicated that the spin state changed from singlet to quintet during ligand elimination. Investigations of the successful hydrosilylation of acetophenone and benzaldehyde derivatives using MIC-iron(II) bromide suggested the importance of the base for efficient conversion in the catalytic process. The bromide-to-hydride exchange reaction, transmetallation, of MIC-iron(II) bromide in the presence of KOtBu and HSi(OEt)3 which could occur in the initial process of hydrosilylation was proposed, and supported by a theoretical study.
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Affiliation(s)
- Kouki Matsubara
- Department of Chemistry, Fukuoka University, 8-19-1 Nanakuma, Fukuoka 814-0180, Japan.
| | - Yuji Yamada
- Department of Chemistry, Fukuoka University, 8-19-1 Nanakuma, Fukuoka 814-0180, Japan.
| | - Haruka Iwasaki
- Department of Chemistry, Fukuoka University, 8-19-1 Nanakuma, Fukuoka 814-0180, Japan.
| | - Hayao Ikeda
- Department of Chemistry, Fukuoka University, 8-19-1 Nanakuma, Fukuoka 814-0180, Japan.
| | - Yuki Kanetsugu
- Department of Chemistry, Fukuoka University, 8-19-1 Nanakuma, Fukuoka 814-0180, Japan.
| | - Satoshi Kawata
- Department of Chemistry, Fukuoka University, 8-19-1 Nanakuma, Fukuoka 814-0180, Japan.
| | - Yuji Koga
- Department of Chemistry, Fukuoka University, 8-19-1 Nanakuma, Fukuoka 814-0180, Japan.
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2
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Doll JS, Regenauer NI, Bothe VP, Wadepohl H, Roşca DA. Redox Activity of Iron Diazine-Diimine Carbonyl and Dinitrogen Complexes: A Comparative Study of the Influence of the Heterocyclic Ring. Inorg Chem 2021; 61:520-532. [PMID: 34913670 DOI: 10.1021/acs.inorgchem.1c03212] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A detailed investigation of the electronic structure of diazinediimine iron complexes and their comparison with the pyridine analogues reveals subtle but important differences, imparted by the supporting heterocycle. In the case of LFe(CO)2 complexes (L = pyrazine- and pyrimidinediimine), the characterization of three available redox states confirmed that whereas the nature of the electron-transfer processes is similar, the differences in π-acidity of the supporting heterocycle significantly affect the redox potentials. The reduction of LFe(CO)2 can yield either a ligand-centered radical (for L = pyrimidine) or a C-C-bonded dimer (for L = pyrazine), supported by a dearomatized core. In the latter case, the C-C bond can be reversibly cleaved oxidatively. Compared to the carbonyl analogues, employing weak-field N2 ligands triggers changes in electronic structure for the neutral and reduced LFe(N2) complexes (L = pyrimidinediimine). En route to the synthesis of the nitrogen complexes, the square-planar LFeCl (L = pyrimidinediimine) was isolated. The monoradical character of the supporting chelate triggers the asymmetric distribution of electron density around the heterocycle.
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Affiliation(s)
- Julianna S Doll
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, 69120 Heidelberg, Germany
| | - Nicolas I Regenauer
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, 69120 Heidelberg, Germany
| | - Viktoria P Bothe
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, 69120 Heidelberg, Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, 69120 Heidelberg, Germany
| | - Dragoş-Adrian Roşca
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, 69120 Heidelberg, Germany
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3
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Song LC, Feng L, Lu Y, Yang XY. Synthesis, Structures, and Reactivity of [NiFe]-H 2ase Mimics Containing One Square-Planar N 2S 2 Ligand Bridged between Their Ni/Fe Centers through One or Two S Atoms. Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00778] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Li-Cheng Song
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Li Feng
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Yu Lu
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Xi-Yue Yang
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
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4
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Lutz SA, Hickey AK, Gao Y, Chen CH, Smith JM. Two-State Reactivity in Iron-Catalyzed Alkene Isomerization Confers σ-Base Resistance. J Am Chem Soc 2020; 142:15527-15535. [PMID: 32786744 DOI: 10.1021/jacs.0c07300] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A low-coordinate, high spin (S = 3/2) organometallic iron(I) complex is a catalyst for the isomerization of alkenes. A combination of experimental and computational mechanistic studies supports a mechanism in which alkene isomerization occurs by the allyl mechanism. Importantly, while substrate binding occurs on the S = 3/2 surface, oxidative addition to an η1-allyl intermediate only occurs on the S = 1/2 surface. Since this spin state change is only possible when the alkene substrate is bound, the catalyst has high immunity to typical σ-base poisons due to the antibonding interactions of the high spin state.
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Affiliation(s)
- Sean A Lutz
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Anne K Hickey
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Yafei Gao
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Chun-Hsing Chen
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Jeremy M Smith
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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5
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Glatz M, Stöger B, Bichler B, Bauer G, Veiros LF, Pignitter M, Kirchner K. Base‐Initiated Formation of Fe
I
–PNP Pincer Complexes. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.201900895] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Mathias Glatz
- Institute of Applied Synthetic Chemistry Vienna University of Technology Getreidemarkt 9, A ‐1060 Vienna Austria
| | - Berthold Stöger
- X‐ray Center Vienna University of Technology Getreidemarkt 9, A ‐1060 Vienna Austria
| | - Bernhard Bichler
- Institute of Applied Synthetic Chemistry Vienna University of Technology Getreidemarkt 9, A ‐1060 Vienna Austria
| | - Gerald Bauer
- Institute of Applied Synthetic Chemistry Vienna University of Technology Getreidemarkt 9, A ‐1060 Vienna Austria
| | - Luis F. Veiros
- Centro de Química Estrutural Instituto Superior Técnico Universidade de Lisboa Av. Rovisco Pais No. 1 1049‐001 Lisboa Portugal
| | - Marc Pignitter
- Department of Physiological Chemistry Faculty of Chemistry University of Vienna Althanstrasse 14 1090 Vienna Austria
| | - Karl Kirchner
- Institute of Applied Synthetic Chemistry Vienna University of Technology Getreidemarkt 9, A ‐1060 Vienna Austria
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6
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Importance of thorough conformational analysis in modelling transition metal-mediated reactions: Case studies on pincer complexes containing phosphine groups. JOURNAL OF SAUDI CHEMICAL SOCIETY 2019. [DOI: 10.1016/j.jscs.2019.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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7
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Pecak J, Glatz M, Stöger B, Bittner R, Hoffmann H, Atkins A, González L, Kirchner K. Visible light-induced cis/trans isomerization of dicarbonyl Fe(II) PNP pincer complexes. Polyhedron 2018. [DOI: 10.1016/j.poly.2017.08.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Employing a neutral “PN3P” pincer to access mer-Re(I) tricarbonyl complexes: Autoionization of a halo ligand and the role of an N-R (R = H, Me) substituent. Polyhedron 2018. [DOI: 10.1016/j.poly.2017.08.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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9
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10
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Cook BJ, Polezhaev AV, Chen C, Pink M, Caulton KG. Deprotonation, Chloride Abstraction, and Dehydrohalogenation as Synthetic Routes to Bis‐Pyrazolate Pyridyl Iron(II) Complexes. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700558] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Brian J. Cook
- Department of Chemistry Indiana University 800 East Kirkwood Avenue 47405 Bloomington Indiana USA
| | - Alexander V. Polezhaev
- Department of Chemistry Indiana University 800 East Kirkwood Avenue 47405 Bloomington Indiana USA
| | - Chun‐Hsing Chen
- Department of Chemistry Indiana University 800 East Kirkwood Avenue 47405 Bloomington Indiana USA
| | - Maren Pink
- Department of Chemistry Indiana University 800 East Kirkwood Avenue 47405 Bloomington Indiana USA
| | - Kenneth G. Caulton
- Department of Chemistry Indiana University 800 East Kirkwood Avenue 47405 Bloomington Indiana USA
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11
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12
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Synthesis, characterization and reactivity of vanadium, chromium, and manganese PNP pincer complexes. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2016.02.064] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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13
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Tondreau AM, Boncella JM. The synthesis of PNP-supported low-spin nitro manganese(I) carbonyl complexes. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.04.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Glatz M, Schröder-Holzhacker C, Bichler B, Stöger B, Mereiter K, Veiros LF, Kirchner K. Synthesis and characterization of cationic dicarbonyl Fe(II) PNP pincer complexes. MONATSHEFTE FUR CHEMIE 2016; 147:1713-1719. [PMID: 27729712 PMCID: PMC5028400 DOI: 10.1007/s00706-016-1811-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 06/26/2016] [Indexed: 11/03/2022]
Abstract
ABSTRACT In the present work, we have prepared a series of octahedral Fe(II) complexes of the type trans-[Fe(PNP)(CO)2Cl]+-PNP are tridentate pincer-type ligands based on 2,6-diaminopyridine. These complexes are formed irrespective of the size of the substituents at the phosphorus sites and whether cis-[Fe(PNP)(Cl2)(CO)] or trans-[Fe(PNP)(Cl2)(CO)] are reacted with CO in the presence of 1 equiv of silver salts. X-ray structures of representative complexes are presented. Based on simple bonding considerations the selective formation of trans-dicarbonyl Fe(II) complexes is unexpected. In fact, DFT calculations confirm that trans-dicarbonyl complexes are indeed thermodynamically disfavored over the respective cis-dicarbonyl compounds, but are favored for kinetic reasons. GRAPHICAL ABSTRACT
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Affiliation(s)
- Mathias Glatz
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163, 1060 Vienna, Austria
| | - Christian Schröder-Holzhacker
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163, 1060 Vienna, Austria
| | - Bernhard Bichler
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163, 1060 Vienna, Austria
| | - Berthold Stöger
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Kurt Mereiter
- 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, 1060 Vienna, Austria
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15
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Schröder-Holzhacker C, Gorgas N, Stöger B, Kirchner K. Synthesis and reactivity of BINEPINE-based chiral Fe(II) PNP pincer complexes. MONATSHEFTE FUR CHEMIE 2016; 147:1023-1030. [PMID: 27340297 PMCID: PMC4869728 DOI: 10.1007/s00706-016-1706-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 02/11/2016] [Indexed: 11/25/2022]
Abstract
ABSTRACT A new asymmetric chiral PNP ligand based on the 2,6-diaminopyridine scaffold featuring a R-BINEPINE moiety was prepared. Treatment of anhydrous FeX2 (X = Cl, Br) with 1 equiv of PNP-iPr,BIN at room temperature afforded the coordinatively unsaturated paramagnetic complexes [Fe(PNP-iPr,BIN)X2]. The structure of [Fe(PNP-iPr,BIN)Cl2] is described. Both complexes react readily with the strong π-acceptor ligand CO in solution to afford selectively the diamagnetic complexes trans-[Fe(PNP-iPr,BIN)(CO)X2] in quantitative yield. Due the lability of the CO ligand, these complexes are only stable under a CO atmosphere and isolation in pure form was not possible. The preparation of the carbonyl hydride complex [Fe(PNP-iPr,BIN)(H)(CO)Br] was achieved albeit in low yields via a one pot procedure by treatment of [Fe(PNP-iPr,BINEP)Br2] with CO and subsequent reaction with Na[HBEt3]. This complex was obtained as an inseparable mixture of two diastereomers in a ca. 1:1 ratio and was tested as catalyst for the hydrogenation of ketones. The catalyst showed acceptable activity under mild conditions (5 bar H2, room temperature) with yields up to >99 % within 18 h. GRAPHICAL ABSTRACT
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Affiliation(s)
- Christian Schröder-Holzhacker
- />Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163-OC, 1060 Vienna, Austria
| | - Nikolaus Gorgas
- />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
| | - Karl Kirchner
- />Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163-OC, 1060 Vienna, Austria
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16
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Bauer G, Hu X. Recent developments of iron pincer complexes for catalytic applications. Inorg Chem Front 2016. [DOI: 10.1039/c5qi00262a] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Iron pincer complexes exhibit excellent activity in homogeneous catalysis.
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Affiliation(s)
- Gerald Bauer
- Laboratory of Inorganic Synthesis and Catalysis
- Institute of Chemical Sciences and Engineering
- École Polytechnique Fédérale de Lausanne (EPFL)
- 1015 Lausanne
- Switzerland
| | - Xile Hu
- Laboratory of Inorganic Synthesis and Catalysis
- Institute of Chemical Sciences and Engineering
- École Polytechnique Fédérale de Lausanne (EPFL)
- 1015 Lausanne
- Switzerland
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17
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Rao GK, Gorelsky SI, Korobkov I, Richeson D. Coinage metal complexes supported by a "PN(3)P" scaffold. Dalton Trans 2015; 44:19153-62. [PMID: 26485392 DOI: 10.1039/c5dt03515e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A series of monovalent group 11 complexes, [2,6-{Ph2PNMe}2(NC5H3)]CuBr 1, [2,6-{Ph2PNMe}2(NC5H3)]CuOTf 2, [2,6-{Ph2PNMe}2(NC5H3)]AgOTf 3, and [2,6-{Ph2PNMe}2(NC5H3)](AuCl)24, supported by a neutral PN(3)P ligand have been synthesized and characterized by multinuclear NMR and single crystal X-ray diffraction studies. The variation of the coordination properties were analyzed and electronic structure calculations have been carried out to provide insight on the bonding details in these complexes. The Cu(I) complexes displayed an unusual coordination geometry with a tridentate pincer ligand and an overall four coordinate trigonal pyramidal geometry. In contrast the Ag(I) analogue displayed a bidentate κ(2)-P,P' ligation leaving the pyridyl-N atom uncoordinated and yielding a pyramidalized trigonal planar geometry around Ag. The bimetallic Au(I) complex completed the series and displayed a monodentate P-bonded ligand and a linear coordination geometry.
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Affiliation(s)
- Gyandshwar Kumar Rao
- Center for Catalysis Research and Innovation and Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
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18
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Rösler S, Ertl M, Irrgang T, Kempe R. Cobalt-Catalyzed Alkylation of Aromatic Amines by Alcohols. Angew Chem Int Ed Engl 2015; 54:15046-50. [DOI: 10.1002/anie.201507955] [Citation(s) in RCA: 253] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Indexed: 12/13/2022]
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19
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Rösler S, Ertl M, Irrgang T, Kempe R. Cobalt-katalysierte Alkylierung von aromatischen Aminen durch Alkohole. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507955] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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20
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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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Huber R, Bigler R, Mezzetti A. Chiral Iron(II) NPPN Complexes: Synthesis and Application in the Asymmetric Strecker Reaction of Azomethine Imines. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00357] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Raffael Huber
- Department
of Chemistry and
Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Raphael Bigler
- Department
of Chemistry and
Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Antonio Mezzetti
- Department
of Chemistry and
Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
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22
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Bichler B, Glatz M, Stöger B, Mereiter K, Veiros LF, Kirchner K. An iron(II) complex featuring κ(3) and labile κ(2)-bound PNP pincer ligands - striking differences between CH2 and NH spacers. Dalton Trans 2015; 43:14517-9. [PMID: 25138445 DOI: 10.1039/c4dt01933d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Treatment of anhydrous FeCl2 with 2 equiv. of the pincer ligand PNP-Ph afforded the diamagnetic cationic octahedral complex [Fe(κ(3)-P,N,P-PNP)(κ(2)-P,N-PNP)Cl](+) featuring a κ(2)-P,N-bound PNP ligand. Preliminary reactivity studies revealed that the κ(2)-P,N-bound PNP ligand is labile reacting with CO to afford trans-[Fe(PNP-Ph)(CO)2Cl](+).
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Affiliation(s)
- Bernhard Bichler
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria.
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23
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Chilton NF, Lei H, Bryan AM, Grandjean F, Long GJ, Power PP. Ligand field influence on the electronic and magnetic properties of quasi-linear two-coordinate iron(ii) complexes. Dalton Trans 2015; 44:11202-11. [DOI: 10.1039/c5dt01589h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The magnetic properties and ligand-field effects for quasi-linear iron(ii) complexes are explored with the aid of theoretical models.
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Affiliation(s)
| | - Hao Lei
- Department of Chemistry
- University of California at Davis
- Davis
- USA
| | - Aimee M. Bryan
- Department of Chemistry
- University of California at Davis
- Davis
- USA
| | - Fernande Grandjean
- Department of Chemistry
- Missouri University of Science and Technology
- University of Missouri
- Rolla
- USA
| | - Gary J. Long
- Department of Chemistry
- Missouri University of Science and Technology
- University of Missouri
- Rolla
- USA
| | - Philip P. Power
- Department of Chemistry
- University of California at Davis
- Davis
- USA
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Murugesan S, Stöger B, Carvalho MD, Ferreira L, Pittenauer E, Allmaier G, Veiros LF, Kirchner K. Synthesis and Reactivity of Four- and Five-Coordinate Low-Spin Cobalt(II) PCP Pincer Complexes and Some Nickel(II) Analogues. Organometallics 2014; 33:6132-6140. [PMID: 27642210 PMCID: PMC5021385 DOI: 10.1021/om5007769] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Indexed: 11/29/2022]
Abstract
Anhydrous CoCl2 or [NiCl2(DME)] reacts with the ligand PCPMe-iPr (1) in the presence of nBuLi to afford the 15e and 16e square planar complexes [Co(PCPMe-iPr)Cl] (2) and [Ni(PCPMe-iPr)Cl] (3), respectively. Complex 2 is a paramagnetic d7 low-spin complex, which is a useful precursor for a series of Co(I), Co(II), and Co(III) PCP complexes. Complex 2 reacts readily with CO and pyridine to afford the five-coordinate square-pyramidal 17e complexes [Co(PCPMe-iPr)(CO)Cl] (4) and [Co(PCPMe-iPr)(py)Cl] (5), respectively, while in the presence of Ag+ and CO the cationic complex [Co(PCPMe-iPr)(CO)2]+ (6) is afforded. The effective magnetic moments μeff of all Co(II) complexes were derived from the temperature dependence of the inverse molar magnetic susceptibility by SQUID measurements and are in the range 1.9 to 2.4 μB. This is consistent with a d7 low-spin configuration with some degree of spin-orbit coupling. Oxidation of 2 with CuCl2 affords the paramagnetic Co(III) PCP complex [Co(PCPMe-iPr)Cl2] (7), while the synthesis of the diamagnetic Co(I) complex [Co(PCPMe-iPr)(CO)2] (8) was achieved by stirring 2 in toluene with KC8 in the presence of CO. Finally, the cationic 16e Ni(II) PCP complex [Ni(PCPMe-iPr)(CO)]+ (10) was obtained by reacting complex 3 with 1 equiv of AgSbF6 in the presence of CO. The reactivity of CO addition to Co(I), Co(II), and Ni(II) PCP square planar complexes of the type [M(PCPMe-iPr)(CO)] n (n = +1, 0) was investigated by DFT calculations, showing that formation of the Co species, 6 and 8, is thermodynamically favorable, while Ni(II) maintains the 16e configuration since CO addition is unfavorable in this case. X-ray structures of most complexes are provided and discussed. A structural feature of interest is that the apical CO ligand in 4 deviates significantly from linearity, with a Co-C-O angle of 170.0(1)°. The DFT-calculated value is 172°, clearly showing that this is not a packing but an electronic effect.
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Affiliation(s)
- Sathiyamoorthy Murugesan
- Institute
of Applied Synthetic Chemistry and Institute of Chemical Technologies
and Analytics, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Berthold Stöger
- Institute
of Applied Synthetic Chemistry and Institute of Chemical Technologies
and Analytics, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Maria Deus Carvalho
- Centro de Química e Bioquímica/DQB and Centro de Física
da Matéria
Condensada, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Liliana
P. Ferreira
- Centro de Química e Bioquímica/DQB and Centro de Física
da Matéria
Condensada, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Department
of Physics, University of Coimbra, 3004-516 Coimbra, Portugal
| | - Ernst Pittenauer
- Institute
of Applied Synthetic Chemistry and Institute of Chemical Technologies
and Analytics, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Günter Allmaier
- Institute
of Applied Synthetic Chemistry and Institute of Chemical Technologies
and Analytics, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Luis F. Veiros
- Centro de
Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais No. 1, 1049-001 Lisboa, Portugal
| | - Karl Kirchner
- Institute
of Applied Synthetic Chemistry and Institute of Chemical Technologies
and Analytics, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
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25
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Sonnenberg JF, Lough AJ, Morris RH. Synthesis of Iron P-N-P′ and P-NH-P′ Asymmetric Hydrogenation Catalysts. Organometallics 2014. [DOI: 10.1021/om5008083] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Jessica F. Sonnenberg
- Davenport Laboratories, Department
of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Alan J. Lough
- Davenport Laboratories, Department
of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Robert H. Morris
- Davenport Laboratories, Department
of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
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26
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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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27
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Four- and five-coordinate high-spin iron(II) complexes bearing bidentate soft/hard SN ligands based on 2-aminopyridine. Polyhedron 2014. [DOI: 10.1016/j.poly.2014.05.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Lagaditis PO, Sues PE, Sonnenberg JF, Wan KY, Lough AJ, Morris RH. Iron(II) Complexes Containing Unsymmetrical P–N–P′ Pincer Ligands for the Catalytic Asymmetric Hydrogenation of Ketones and Imines. J Am Chem Soc 2014; 136:1367-80. [DOI: 10.1021/ja4082233] [Citation(s) in RCA: 251] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Paraskevi O. Lagaditis
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 Canada
| | - Peter E. Sues
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 Canada
| | - Jessica F. Sonnenberg
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 Canada
| | - Kai Yang Wan
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 Canada
| | - Alan J. Lough
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 Canada
| | - Robert H. Morris
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 Canada
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29
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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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30
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Bichler B, Holzhacker C, Stöger B, Puchberger M, Veiros LF, Kirchner K. Heterolytic Cleavage of Dihydrogen by an Iron(II) PNP Pincer Complex via Metal-Ligand Cooperation. Organometallics 2013; 32:4114-4121. [PMID: 23990692 PMCID: PMC3751463 DOI: 10.1021/om400241x] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Indexed: 01/24/2023]
Abstract
The bis-carbonyl Fe(II) complex trans-[Fe(PNP-iPr)(CO)2Cl]+ reacts with Zn as reducing agent under a dihydrogen atmosphere to give the Fe(II) hydride complex cis-[Fe(PNP-iPr)(CO)2H]+ in 97% isolated yield. A crucial step in this reaction seems to be the reduction of the acidic NH protons of the PNP-iPr ligand to afford H2 and the coordinatively unsaturated intermediate [Fe(PNPH-iPr)(CO)2]+ bearing a dearomatized pyridine moiety. This species is able to bind and heterolytically cleave H2 to give cis-[Fe(PNP-iPr)(CO)2H]+. The mechanism of this reaction has been studied by DFT calculations. The proposed mechanism was supported by deuterium labeling experiments using D2 and the N-deuterated isotopologue of trans-[Fe(PNP-iPr)(CO)2Cl]+. While in the first case deuterium was partially incorporated into both N and Fe sites, in the latter case no reaction took place. In addition, the N-methylated complex trans-[Fe(PNPMe-iPr)(CO)2Cl]+ was prepared, showing no reactions with Zn and H2 under the same reaction conditions. An alternative synthesis of cis-[Fe(PNP-iPr)(CO)2H]+ was developed utilizing the Fe(0) complex [Fe(PNP-iPr)(CO)2]. This compound is obtained in high yield by treatment of either trans-[Fe(PNP-iPr)(CO)2Cl]+ or [Fe(PNP-iPr)Cl2] with an excess of NaHg or a stoichiometric amount of KC8 in the presence of carbon monoxide. Protonation of [Fe(PNP-iPr)(CO)2] with HBF4 gave the hydride complex cis-[Fe(PNP-iPr)(CO)2H]+. X-ray structures of both cis-[Fe(PNP-iPr)(CO)2H]+ and [Fe(PNP-iPr)(CO)2] are presented.
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Affiliation(s)
- Bernhard Bichler
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Christian Holzhacker
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Berthold Stöger
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Michael Puchberger
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Luis F. Veiros
- Centro de Química Estrutural, Instituto
Superior Técnico, Universidade Técnica
de Lisboa, Av. Rovisco Pais No. 1, 1049-001 Lisboa,
Portugal
| | - Karl Kirchner
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
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31
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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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32
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Öztopcu Ö, Holzhacker C, Puchberger M, Weil M, Mereiter K, Veiros LF, Kirchner K. Synthesis and Characterization of Hydrido Carbonyl Molybdenum and Tungsten PNP Pincer Complexes. Organometallics 2013; 32:3042-3052. [PMID: 23794778 PMCID: PMC3688336 DOI: 10.1021/om400254k] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Indexed: 11/28/2022]
Abstract
In the present study the Mo(0) and W(0) complexes [M(PNP)(CO)3] as well as seven-coordinate cationic hydridocarbonyl Mo(II) and W(II) complexes of the type [M(PNP)(CO)3H]+, featuring PNP pincer ligands based on 2,6-diaminopyridine, have been prepared and fully characterized. The synthesis of Mo(0) complexes [Mo(PNP)(CO)3] was accomplished by treatment of [Mo(CO)3(CH3CN)3] with the respective PNP ligands. The analogous W(0) complexes were prepared by reduction of the bromocarbonyl complexes [W(PNP)(CO)3Br]+ with NaHg. These intermediates were obtained from the known dinuclear complex [W(CO)4(μ-Br)Br]2, prepared in situ from W(CO)6 and stoichiometric amounts of Br2. Addition of HBF4 to [M(PNP)(CO)3] resulted in clean protonation at the molybdenum and tungsten centers to generate the Mo(II) and W(II) hydride complexes [M(PNP)(CO)3H]+. The protonation is fully reversible, and upon addition of NEt3 as base the Mo(0) and W(0) complexes [M(PNP)(CO)3] are regenerated quantitatively. All heptacoordinate complexes exhibit fluxional behavior in solution. The mechanism of the dynamic process of the hydrido carbonyl complexes was investigated by means of DFT calculations, revealing that it occurs in a single step. The structures of representative complexes were determined by X-ray single-crystal analyses.
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Affiliation(s)
- Özgür Öztopcu
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Christian Holzhacker
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Michael Puchberger
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Matthias Weil
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Kurt Mereiter
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Luis F. Veiros
- Centro de Química Estrutural, Instituto
Superior Técnico, Universidade Técnica
de Lisboa, Av. Rovisco Pais No. 1, 1049-001 Lisboa,
Portugal
| | - Karl Kirchner
- Institute
of Applied Synthetic Chemistry, Institute of Materials Chemistry, and Institute of Chemical
Technologies and Analytics, Vienna University
of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
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33
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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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34
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Bhattacharya P, Krause JA, Guan H. Iron Hydride Complexes Bearing Phosphinite-Based Pincer Ligands: Synthesis, Reactivity, and Catalytic Application in Hydrosilylation Reactions. Organometallics 2011. [DOI: 10.1021/om2005589] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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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35
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Benito-Garagorri D, Lagoja I, Veiros LF, Kirchner KA. Reactivity of coordinatively unsaturated iron complexes towards carbon monoxide: to bind or not to bind? Dalton Trans 2011; 40:4778-92. [PMID: 21380474 DOI: 10.1039/c0dt01636e] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An overview of the reactivity of coordinatively unsaturated iron complexes (in most cases Fe(II)) towards carbon monoxide is presented. Unsaturated iron complexes are known with coordination numbers (CN) of two to five adopting linear or slightly bent (CN = 2), trigonal (CN = 3), tetrahedral, square planar or trigonal pyramidal (CN = 4), and square-pyramidal or trigonal-bipyramidal geometries (CN = 5), respectively. The binding of CO depends strongly on the number and the nature of co-ligands (overall ligand field strength), the charge of the complex, the complex geometry, and the spin state of the unsaturated metal center. In many cases, CO addition to high-spin iron complexes takes place with concomitant spin state changes forming compounds in the lowest possible spin state, i.e., with S = 0. In several other cases, however, the addition of CO is reversible or is even totally rejected altogether for either thermodynamic or kinetic reasons. In the case of the latter such reactions are termed "spin-blocked" or "spin forbidden".
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Affiliation(s)
- David Benito-Garagorri
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060, Vienna, Austria.
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36
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37
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Sadimenko AP. Organometallic Complexes of Phosphinopyridines and Related Ligands. ADVANCES IN HETEROCYCLIC CHEMISTRY VOLUME 104 2011. [DOI: 10.1016/b978-0-12-388406-0.00003-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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38
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Alves LG, Dazinger G, Veiros LF, Kirchner K. Unusual Anion Effects in the Iron-Catalyzed Formation of 3-Hydroxyacrylates from Aromatic Aldehydes and Ethyl Diazoacetate. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000240] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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