1
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Landaeta VR, Horsley Downie TM, Wolf R. Low-Valent Transition Metalate Anions in Synthesis, Small Molecule Activation, and Catalysis. Chem Rev 2024; 124:1323-1463. [PMID: 38354371 PMCID: PMC10906008 DOI: 10.1021/acs.chemrev.3c00121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 10/09/2023] [Accepted: 10/09/2023] [Indexed: 02/16/2024]
Abstract
This review surveys the synthesis and reactivity of low-oxidation state metalate anions of the d-block elements, with an emphasis on contributions reported between 2006 and 2022. Although the field has a long and rich history, the chemistry of transition metalate anions has been greatly enhanced in the last 15 years by the application of advanced concepts in complex synthesis and ligand design. In recent years, the potential of highly reactive metalate complexes in the fields of small molecule activation and homogeneous catalysis has become increasingly evident. Consequently, exciting applications in small molecule activation have been developed, including in catalytic transformations. This article intends to guide the reader through the fascinating world of low-valent transition metalates. The first part of the review describes the synthesis and reactivity of d-block metalates stabilized by an assortment of ligand frameworks, including carbonyls, isocyanides, alkenes and polyarenes, phosphines and phosphorus heterocycles, amides, and redox-active nitrogen-based ligands. Thereby, the reader will be familiarized with the impact of different ligand types on the physical and chemical properties of metalates. In addition, ion-pairing interactions and metal-metal bonding may have a dramatic influence on metalate structures and reactivities. The complex ramifications of these effects are examined in a separate section. The second part of the review is devoted to the reactivity of the metalates toward small inorganic molecules such as H2, N2, CO, CO2, P4 and related species. It is shown that the use of highly electron-rich and reactive metalates in small molecule activation translates into impressive catalytic properties in the hydrogenation of organic molecules and the reduction of N2, CO, and CO2. The results discussed in this review illustrate that the potential of transition metalate anions is increasingly being tapped for challenging catalytic processes with relevance to organic synthesis and energy conversion. Therefore, it is hoped that this review will serve as a useful resource to inspire further developments in this dynamic research field.
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Affiliation(s)
| | | | - Robert Wolf
- University of Regensburg, Institute
of Inorganic Chemistry, 93040 Regensburg, Germany
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2
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Yang ES, Wilson DWN, Goicoechea JM. Metal-Mediated Oligomerization Reactions of the Cyaphide Anion. Angew Chem Int Ed Engl 2023; 62:e202218047. [PMID: 36656139 PMCID: PMC10946887 DOI: 10.1002/anie.202218047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/20/2023]
Abstract
The cyaphide anion, CP- , is shown to undergo three distinct oligomerization reactions in the coordination sphere of metals. Reductive coupling of Au(IDipp)(CP) (IDipp=1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) by Sm(Cp*)2 (OEt2 ) (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl), was found to afford a tetra-metallic complex containing a 2,3-diphosphabutadiene-1,1,4,4-tetraide fragment. By contrast, non-reductive dimerization of Ni(SIDipp)(Cp)(CP) (SIDipp=1,3-bis(2,6-diisopropylphenyl)-imidazolidin-2-ylidene; Cp=cyclopentadienyl), gives rise to an asymmetric bimetallic complex containing a 1,3-diphosphacyclobutadiene-2,4-diide moiety. Spontaneous trimerization of Sc(Cp*)2 (CP) results in the formation of a trimetallic complex containing a 1,3,5-triphosphabenzene-2,4,6-triide fragment. These transformations show that while cyaphido transition metal complexes can be readily accessed using metathesis reactions, many such species are unstable to further oligomerization processes.
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Affiliation(s)
- Eric S. Yang
- Department of ChemistryUniversity of OxfordChemistry Research Laboratory12 Mansfield RoadOxfordOX1 3TAUK
| | - Daniel W. N. Wilson
- Department of ChemistryUniversity of OxfordChemistry Research Laboratory12 Mansfield RoadOxfordOX1 3TAUK
| | - Jose M. Goicoechea
- Department of ChemistryUniversity of OxfordChemistry Research Laboratory12 Mansfield RoadOxfordOX1 3TAUK
- Department of ChemistryIndiana University—Bloomington800 E. Kirkwood Ave.BloomingtonIN-47405-7102USA
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3
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Scharnhölz MT, Coburger P, Gravogl L, Klose D, Gamboa‐Carballo JJ, Le Corre G, Bösken J, Schweinzer C, Thöny D, Li Z, Meyer K, Grützmacher H. Bis(imidazolium)-1,3-diphosphete-diide: A Building Block for FeC 2 P 2 Complexes and Clusters. Angew Chem Int Ed Engl 2022; 61:e202205371. [PMID: 35661524 PMCID: PMC9796810 DOI: 10.1002/anie.202205371] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Indexed: 01/07/2023]
Abstract
Reaction of the 6π-electron aromatic four-membered heterocycle (IPr)2 C2 P2 (1) (IPr=1,3-bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene) with [Fe2 CO9 ] gives the neutral iron tricarbonyl complex [Fe(CO)3 -η3 -{(IPr)2 C2 P2 }] (2). Oxidation with two equivalents of the ferrocenium salt, [Fe(Cp)2 ](BArF24 ), affords the dicationic tricarbonyl complex [Fe(CO)3 -η4 -{(IPr)2 C2 P2 }](BArF24 )2 (4). The one-electron oxidation proceeds under concomitant loss of one CO ligand to give the paramagnetic dicarbonyl radical cation complex [Fe(CO)2 -η4 -{(IPr)2 C2 P2 }](BArF24 ) (5). Reduction of 5 allows the preparation of the neutral dicarbonyl complex [Fe(CO)2 -η4 -{(IPr)2 C2 P2 }] (6). An analysis by various spectroscopic techniques (57 Fe Mössbauer, EPR) combined with DFT calculations gives insight into differences of the electronic structure within the members of this unique series of iron carbonyl complexes, which can be either described as electron precise or Wade-Mingos clusters.
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Affiliation(s)
| | - Peter Coburger
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Lisa Gravogl
- Department of Chemistry and PharmacyInorganic ChemistryFriedrich-Alexander-Universität Erlangen-Nürnberg (FAU)Egerlandstr. 191058ErlangenGermany
| | - Daniel Klose
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Juan José Gamboa‐Carballo
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland,Higher Institute of Technologies and Applied Sciences (InSTEC)University of HavanaAve. S. Allende 111010600HavanaCuba
| | - Grégoire Le Corre
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Jonas Bösken
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Clara Schweinzer
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Debora Thöny
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
| | - Zhongshu Li
- Lehn Institute of Functional Materials (LIFM)School of ChemistrySun Yat-Sen University510275GuangzhouChina,State Key Laboratory of Elemento-Organic ChemistryNankai University30071TianjinChina
| | - Karsten Meyer
- Department of Chemistry and PharmacyInorganic ChemistryFriedrich-Alexander-Universität Erlangen-Nürnberg (FAU)Egerlandstr. 191058ErlangenGermany
| | - Hansjörg Grützmacher
- Department of Chemistry and Applied BiosciencesETH ZürichVladimir-Prelog-Weg 18093ZürichSwitzerland
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4
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Zagidullin AA, Akhmatkhanova FF, Khrizanforov MN, Fayzullin RR, Gerasimova TP, Bezkishko IA, Miluykov VA. Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes. Beilstein J Org Chem 2022; 18:1338-1345. [PMID: 36247980 PMCID: PMC9531555 DOI: 10.3762/bjoc.18.139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/09/2022] [Indexed: 11/24/2022] Open
Abstract
A novel representative of sodium 3,4,5-triaryl-1,2-diphosphacyclopentadienide containing a chloro substituent in the meta-position of the aryl groups was obtained with a high yield based on the reaction of tributyl(1,2,3-triarylcyclopropenyl)phosphonium bromide and sodium polyphosphides. Further reaction of sodium 3,4,5-tris(3-chlorophenyl)-1,2-diphosphacyclopentadienide with [FeCp(η6-C6H5CH3)][PF6] complex gives a new 3,4,5-tris(3-chlorophenyl)-1,2-diphosphaferrocene. The electrochemical properties of 3,4,5-tris(3-chlorophenyl)-1,2-diphosphaferrocene were studied and compared to 3,4,5-tris(4-chlorophenyl)-1,2-diphosphaferrocene. It was found that the position of the chlorine atom on the aryl fragment has an influence on the reduction potential of 1,2-diphosphaferrocenes, while the oxidation potentials do not change.
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Affiliation(s)
- Almaz A Zagidullin
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, 420088 Kazan, Russian Federation
| | - Farida F Akhmatkhanova
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, 420088 Kazan, Russian Federation
| | - Mikhail N Khrizanforov
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, 420088 Kazan, Russian Federation
| | - Robert R Fayzullin
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, 420088 Kazan, Russian Federation
| | - Tatiana P Gerasimova
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, 420088 Kazan, Russian Federation
| | - Ilya A Bezkishko
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, 420088 Kazan, Russian Federation
| | - Vasili A Miluykov
- Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, 8 Arbuzov Street, 420088 Kazan, Russian Federation
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5
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Scharnhölz MT, Coburger P, Gravogl L, Klose D, Gamboa-Carballo JJ, Le Corre G, Bösken J, Schweinzer C, Thöny D, Meyer K, Li Z, Grützmacher H. Bis(imidazolium)‐1,3‐diphosphete‐diide: A Building Block for FeC2P2 Complexes and Clusters. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- M. T. Scharnhölz
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - P. Coburger
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - L. Gravogl
- FAU: Friedrich-Alexander-Universitat Erlangen-Nurnberg Chemie GERMANY
| | - D. Klose
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - J. J. Gamboa-Carballo
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - G. Le Corre
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - J. Bösken
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - C. Schweinzer
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - D. Thöny
- ETH Zürich: Eidgenossische Technische Hochschule Zurich Chemistry and Applied Biosciences SWITZERLAND
| | - K. Meyer
- FAU: Friedrich-Alexander-Universitat Erlangen-Nurnberg Chemie GERMANY
| | - Z. Li
- Sun Yat-Sen University Chemistry CHINA
| | - Hansjörg Grützmacher
- ETH Hönggerberg Deptmartment of Chemistry Vladimir Prelog Weg 1 8093 Zürich SWITZERLAND
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6
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Hierlmeier G, Coburger P, Scott DJ, Maier TM, Pelties S, Wolf R, Pividori DM, Meyer K, van Leest NP, de Bruin B. Di-tert-butyldiphosphatetrahedrane as a Source of 1,2-Diphosphacyclobutadiene Ligands. Chemistry 2021; 27:14936-14946. [PMID: 34424579 PMCID: PMC8596834 DOI: 10.1002/chem.202102335] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Indexed: 11/18/2022]
Abstract
Reactions of di‐tert‐butyldiphosphatetrahedrane (1) with cycloocta‐1,5‐diene‐ or anthracene‐stabilised metalate anions of iron and cobalt consistently afford complexes of the rarely encountered 1,2‐diphosphacyclobutadiene ligand, which have previously been very challenging synthetic targets. The subsequent reactivity of 1,2‐diphosphacyclobutadiene cobaltates toward various electrophiles has also been investigated and is compared to reactions of related 1,3‐diphosphacyclobutadiene complexes. The results highlight the distinct reactivity of such isomeric species, showing that the 1,2‐isomers can act as precursors for previously unknown triphospholium ligands. The electronic structures of the new complexes were investigated by several methods, including NMR, EPR and Mößbauer spectroscopies as well as quantum chemical calculations.
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Affiliation(s)
- Gabriele Hierlmeier
- Institut für Anorganische Chemie, Universität Regensburg, 93040, Regensburg, Germany
| | - Peter Coburger
- Institut für Anorganische Chemie, Universität Regensburg, 93040, Regensburg, Germany.,present address: Laboratory of Inorganic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Daniel J Scott
- Institut für Anorganische Chemie, Universität Regensburg, 93040, Regensburg, Germany
| | - Thomas M Maier
- Institut für Anorganische Chemie, Universität Regensburg, 93040, Regensburg, Germany
| | - Stefan Pelties
- Institut für Anorganische Chemie, Universität Regensburg, 93040, Regensburg, Germany
| | - Robert Wolf
- Institut für Anorganische Chemie, Universität Regensburg, 93040, Regensburg, Germany
| | - Daniel M Pividori
- Institut für Anorganische Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Karsten Meyer
- Institut für Anorganische Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Nicolaas P van Leest
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam (The, Netherlands
| | - Bas de Bruin
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam (The, Netherlands
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7
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Kelly JA, Gramüller J, Gschwind RM, Wolf R. Low-oxidation state cobalt-magnesium complexes: ion-pairing and reactivity. Dalton Trans 2021; 50:13985-13992. [PMID: 34542141 PMCID: PMC8507399 DOI: 10.1039/d1dt02621f] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 08/09/2021] [Indexed: 11/21/2022]
Abstract
Magnesium cobaltates (Arnacnac)MgCo(COD)2 (1-3) were synthesised by reacting (Arnacnac)MgI(OEt2) with K[Co(η4-COD)2] (COD = 1,5-cyclooctadiene) [Arnacnac = CH(ArNCMe)2; Ar = 2,4,6-Me3-C6H2 (Mes), 2,6-Et2-C6H3 (Dep), 2,6-iPr2-C6H3Mes (Dipp)]. Compounds 1-3 form contact ion-pairs in toluene, while solvent separated ion-pairs are formed in THF. The effect of ion-pairing on the reactivity is illustrated by reaction of 2 with tert-butylphosphaalkyne, which affords distinct 1,3-diphosphacyclobutadiene complexes. The heteroleptic sandwich complex [(Depnacnac)MgCo(P2C2tBu2)]2 (4) is selectively formed in toluene, while the homoleptic bis(1,3-diphosphacyclobutadiene) complex [(Depnacnac)Mg(THF)3][Co(P2C2tBu2)2] (5) is obtained in THF. Complex 4 is a precursor to further unusual phosphaorganometallic compounds. Substitution of the labile COD ligand in 4 by white phosphorus (P4) enabled the synthesis of the phosphorus-rich sandwich compound [(Depnacnac)MgCoP4(P2C2tBu2)]2 (6). The heterobimetallic complex (Cp*NiP2C2tBu2)Co(COD) (7) was isolated after treatment of 4 with Cp*Ni(acac) (Cp* = C5Me5, acac = acetylacetonate).
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Affiliation(s)
- John A Kelly
- University of Regensburg, Institute of Inorganic Chemistry, 93040 Regensburg, Germany.
| | - Johannes Gramüller
- University of Regensburg, Institute of Organic Chemistry, 93040 Regensburg, Germany
| | - Ruth M Gschwind
- University of Regensburg, Institute of Organic Chemistry, 93040 Regensburg, Germany
| | - Robert Wolf
- University of Regensburg, Institute of Inorganic Chemistry, 93040 Regensburg, Germany.
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8
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Coburger P, Leitl J, Scott DJ, Hierlmeier G, Shenderovich IG, Hey-Hawkins E, Wolf R. Synthesis of a carborane-substituted bis(phosphanido) cobaltate(i), ligand substitution, and unusual P 4 fragmentation. Chem Sci 2021; 12:11225-11235. [PMID: 34522320 PMCID: PMC8386647 DOI: 10.1039/d1sc02948g] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/07/2021] [Indexed: 01/13/2023] Open
Abstract
Oxidative addition of the P-P single bond of an ortho-carborane-derived 1,2-diphosphetane (1,2-C2(PMes)2B10H10) (Mes = 2,4,6-Me3C6H2) to cobalt(-i) and nickel(0) sources affords the first heteroleptic complexes of a carborane-bridged bis(phosphanido) ligand. The complexes also incorporate labile ligands suitable for further functionalisation. Thus, the cobalt(i) complex [K([18]crown-6)][Co{1,2-(PMes)2C2B10H10}(cod)] (cod = 1,5-cyclooctadiene) bearing a labile cyclooctadiene ligand undergoes facile ligand exchange reactions with isonitriles and tert-butyl phosphaalkyne with retention of the bis(phosphanido) ligand. However, in the reaction with one equivalent of P4, the electron-rich bis(phosphanido) moiety abstracts a single phosphorus atom with formation of a new P3 chain, while the remaining three P atoms derived from P4 form an η3-coordinating cyclo-P3 ligand. In contrast, when the same reaction is performed with two equivalents of the cobalt(i) complex, a dinuclear product is formed which features an unusual P4 chain in its molecular structure.
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Affiliation(s)
- Peter Coburger
- Institute of Inorganic Chemistry, Universität Regensburg 93040 Regensburg Germany
- Institute of Inorganic Chemistry, Universität Leipzig Johannisallee 29 04103 Leipzig Germany https://anorganik.chemie.uni-leipzig.de/anorganik/ak-hey-hawkins/
| | - Julia Leitl
- Institute of Inorganic Chemistry, Universität Regensburg 93040 Regensburg Germany
| | - Daniel J Scott
- Institute of Inorganic Chemistry, Universität Regensburg 93040 Regensburg Germany
| | - Gabriele Hierlmeier
- Institute of Inorganic Chemistry, Universität Regensburg 93040 Regensburg Germany
| | - Ilya G Shenderovich
- Institute of Organic Chemistry, Universität Regensburg 93040 Regensburg Germany
| | - Evamarie Hey-Hawkins
- Institute of Inorganic Chemistry, Universität Leipzig Johannisallee 29 04103 Leipzig Germany https://anorganik.chemie.uni-leipzig.de/anorganik/ak-hey-hawkins/
| | - Robert Wolf
- Institute of Inorganic Chemistry, Universität Regensburg 93040 Regensburg Germany
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Binuclear 1,3-diphosphacyclobutadiene vanadium carbonyls: Bending of the P2C2 ring in an unsaturated system with a vanadium-vanadium multiple bond. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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10
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Wan X, Wang X, Chen X, Jin R, Du Q, Xie Y, Bruce King R. 1,3-Diphosphacyclobutadiene sandwich compounds as bidentate ligands in metal carbonyl chemistry: Binuclear chromium derivatives. Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2019.119123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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11
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Rödl C, Wolf R. Flexidentate Coordination Behavior and Chemical Non‐Innocence of a Bis(1,3‐Diphosphacyclobutadiene) Sandwich Anion. Chemistry 2019; 25:8332-8343. [DOI: 10.1002/chem.201901061] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Christian Rödl
- University of RegensburgInstitute of Inorganic Chemistry 93040 Regensburg Germany
| | - Robert Wolf
- University of RegensburgInstitute of Inorganic Chemistry 93040 Regensburg Germany
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12
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Rödl C, Schwedtmann K, Weigand JJ, Wolf R. 1,3-Diphosphacyclobutene Cobalt Complexes. Chemistry 2019; 25:6180-6188. [PMID: 30840328 DOI: 10.1002/chem.201900170] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/05/2019] [Indexed: 11/10/2022]
Abstract
The synthesis and characterization of rare 1,3-diphosphacyclobutene transition-metal complexes is described. Reactions of the cobalt-hydride complex [Co(P2 C2 tBu2 )2 H] (G) with nBuLi, tBuLi, or PhLi afforded [Li(solv)x {Co(η3 -P2 C2 tBu2 HR)(η4 -P2 C2 tBu2 )}] (1: R=nBu, (solv)x =(Et2 O)2 ; 2: R=tBu, (solv)x =(thf)2 ; 3: R=Ph, (solv)x =(Et2 O)(thf)2 ), with an η3 -coordinated 1,3-diphosphacyclobutene ligand as a result of organyl-anion attack at one of the phosphorus atoms of the bis(1,3-diphosphacyclobutadiene) backbone. In contrast to the reactions with PhLi, the aryl-magnesium compounds p-tolyl magnesium chloride and p-fluorophenyl magnesium bromide deprotonate [Co(P2 C2 tBu2 )2 H] to give the magnesium salt [Mg(MeCN)6 ][Co(η4 -P2 C2 tBu2 )2 ]2 (4), which contains a bis(1,3-diphosphacyclobutadiene)-cobaltate anion. The [Co(η4 -P2 C2 tBu2 )2 ]- anions are well separated from the octahedral [Mg(MeCN)6 ]2+ cation in the molecular structure of 4. Compound 1 reacts with Me3 SiCl to give neutral [Co(η3 -P2 C2 tBu2 HnBu)(η4 -P2 C2 tBu2 SiMe3 )] (5, 52 % yield) with an SiMe3 group attached to one of the P atoms of the previously unfunctionalized backbone.
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Affiliation(s)
- Christian Rödl
- Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany
| | - Kai Schwedtmann
- Faculty of Chemistry and Food Chemistry, Chair of Inorganic Molecular Chemistry, TU Dresden, 01062, Dresden, Germany
| | - Jan J Weigand
- Faculty of Chemistry and Food Chemistry, Chair of Inorganic Molecular Chemistry, TU Dresden, 01062, Dresden, Germany
| | - Robert Wolf
- Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany
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Rödl C, Malberg JBN, Wolf R. Functionalization of 1,3-diphosphacyclobutadiene cobalt complexes via Si–P bond insertion. ACTA ACUST UNITED AC 2018. [DOI: 10.1515/znb-2018-0121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
We report the synthesis of functionalized 1,3-bis(diphosphacyclobutadiene) complexes via the insertion of carbon-oxygen bonds of ethers, esters, aldehydes and amides into the P–Si bond of silylated complexes. Reactions of [K(tol)2][Co(η
4-P2C2R2)2] [[K(tol)2][1a]: R=tBu, [K(tol)2][1b]: R=tPent (=tert-pentyl)] with Me3SiCl afford the trimethylsilyl-substituted derivatives [Co(η
4-P2C2R2SiMe3)(η
4-P2C2R2)] (2a,
b, R=tBu, tPent). The Me3Si group is connected to a phosphorus atom of one of the 1,3-diphosphacyclobutadiene ligands. 2a,
b readily react with organic substrates containing C–O single and C=O double bonds at ambient temperature. [Co(η
4-P2C2R2(CH2)4OSiMe3)(η
4-P2C2R2)] (3a, b) are formed by reaction of 2a, b with traces of THF. They can also be isolated by reacting the THF solvates [K(thf)2{Co(P2C2
tBu2)2}] ([K(thf)2][1a]) and [K(thf)3{Co(P2C2
tPent2)2}] ([K(thf)3][1b]) with Me3SiCl in toluene or THF. The adamantyl-substituted complex [Co(η
4-P2C2Ad2(CH2)4OSiMe3)(η
4-P2C2Ad2)] (3c) was prepared analogously from [K(thf)4{Co(P2C2Ad2)2}] and Me3SiCl. [K(thf)2][1a] reacts cleanly with Ph3SnCl affording [Co(η
4-P2C2
tBu2SnPh3)(η
4-P2C2
tBu2)] (4) in high yield. Reaction of 2a with styrene oxide affords [Co(η
4-P2C2
tBu2PhC2H3OSiMe3)(η
4-P2C2
tBu2)] (5) as a single regioisomer. By contrast, multinuclear NMR spectroscopic studies indicate mixtures of two isomeric insertion products 6/6′ and 7/7′, respectively, which result from the insertion of 1,2-epoxy-2-methylpropane and 1,2-epoxyoctane. Moreover, these monitoring studies show that reactions of 2a with acyclic ethers afford alkyl substituted complexes such as [Co(η
4-P2C2
tBu2Et)(η
4-P2C2
tBu2)] (8) and alkylsilyl ethers. Reaction of 2a with γ-butyrolactone gives [Co(η
4-P2C2
tBu2(CH2)3C(O)OSiMe3)(η
4-P2C2
tBu2)] (9) via cleavage of the endocyclic C–O single bond of the lactone. Benzaldehyde and acetone cleanly react with 2a to [Co(η
4-P2C2
tBu2CH(Ph)OSiMe3)(η
4-P2C2
tBu2)] (10) and [Co(η
4-P2C2
tBu2CMe2OSiMe3)(η
4-P2C2
tBu2)] (11), while the sterically more demanding ketones 3-pentanone and acetophenone selectively yield the known hydride complex [Co(η
4-P2C2
tBu2)2H] (A). Phenyl isocyanate reacts with 2a at elevated temperature to form [Co(η
3-P2C2
tBu2CON(Ph)SiMe3)(η
4-P2C2
tBu2)] (12) with a functionalized η
3-coordinated ligand. [K(tol)2][1a], [K(tol)2][1b], 2a, 2b, 3a–c, 4, 5, and 9–12 were isolated and characterized by multinuclear NMR spectroscopy, UV/Vis spectroscopy and elemental analysis. [K(tol)2][1b], 2a, 2b, 3c, 4, 5, and 9–12 were additionally characterized by X-ray crystallography.
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Affiliation(s)
- Christian Rödl
- Institut für Anorganische Chemie , Universität Regensburg , Universitätsstraße 31 , 93053 Regensburg , Germany
| | | | - Robert Wolf
- Institut für Anorganische Chemie , Universität Regensburg , Universitätsstraße 31 , 93053 Regensburg , Germany
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14
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Rummel EM, Balázs G, Heinl V, Scheer M. Isomerisierung, Ringerweiterungs- und Ringverengungsreaktionen von 1,3-Diphosphet-Komplexen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201703633] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Eva-Maria Rummel
- Universität Regensburg; Institut für Anorganische Chemie; 93040 Regensburg Deutschland
| | - Gábor Balázs
- Universität Regensburg; Institut für Anorganische Chemie; 93040 Regensburg Deutschland
| | - Veronika Heinl
- Universität Regensburg; Institut für Anorganische Chemie; 93040 Regensburg Deutschland
| | - Manfred Scheer
- Universität Regensburg; Institut für Anorganische Chemie; 93040 Regensburg Deutschland
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15
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Rummel EM, Balázs G, Heinl V, Scheer M. Isomerization, Ring Expansion, and Ring Contraction of 1,3-Diphosphete Complexes. Angew Chem Int Ed Engl 2017; 56:9592-9596. [DOI: 10.1002/anie.201703633] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Eva-Maria Rummel
- University of Regensburg; Department of Inorganic Chemistry; 93040 Regensburg Germany
| | - Gábor Balázs
- University of Regensburg; Department of Inorganic Chemistry; 93040 Regensburg Germany
| | - Veronika Heinl
- University of Regensburg; Department of Inorganic Chemistry; 93040 Regensburg Germany
| | - Manfred Scheer
- University of Regensburg; Department of Inorganic Chemistry; 93040 Regensburg Germany
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16
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Competition between phosphorus lone pairs and ring π-systems in binding to transition metals: Binuclear diphosphacyclobutadiene cobalt carbonyl derivatives. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2016.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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1,3-Diphosphacyclobutadiene as a ligand in binuclear manganese carbonyl derivatives: Role of the ring phosphorus atoms. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2016.02.055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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18
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Wiegel AK, Rad BR, Herrmann D, Wolf R. Synthesis and Characterization of Tetra(pyridyl)cyclobutadiene Iron Complexes [Cp*Fe(C 4py 4)] -(py = 3-pyridyl and 4-pyridyl, Cp* = C 5Me 5). Z Anorg Allg Chem 2015. [DOI: 10.1002/zaac.201500235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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19
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Rödl C, Wolf R. Cobalt(I) and Nickel(II) Complexes of Bis(1,3-diphosphacyclobutadiene) Sandwich Anions. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201500583] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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20
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Ang CY, Kuan SL, Tan GK, Goh LY, Roemmele TL, Yu X, Boeré RT. Coordination complexes of thiazyl rings — Synthesis, structure, and density functional theory (DFT) computational analysis of CpCr(CO)x (x = 2, 3) complexes of fluorinated and nonfluorinated 1λ3-1,2,4,6-thiatriazinyls with differing Cr–S bond orders. CAN J CHEM 2015. [DOI: 10.1139/cjc-2014-0257] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The reaction of [3,5-Ph2-C2N3S]2 with [CpCr(CO)3]2 in toluene at room temperature forms an adduct via a Cr–S bond, formulated as CpCr(CO)3SN3C2Ph2, which has fitting NMR, IR, and combustion analysis data. The structure was determined by a single-crystal X-ray structure diffraction study (P21/n, a = 8.4611(17) Å, b = 20.509(4) Å, c = 11.757(2) Å, β = 104.453(7)°). The Cr–S bond length of 2.4908(11) Å corresponds to a bond order of 1.0 from >90 values for CpCr(CO)x or Cp*Cr(CO)x moieties (x = 2, 3) bonded to S, which are used to establish a Pauling-type bond order scale specific to this class of compounds. Similar reactions of fluorinated thiatriazinyls derived from [3-Ph-5-CF3-C2N3S]2 or [4-MeOC6H4-5-CF3-C2N3S]2 are accompanied by the loss of CO to produce CpCr(CO)2SN3C2PhCF3 (P1, a = 8.0929(8) Å, b = 10.3160(10) Å, c = 11.2405(11) Å, α = 70.032(2)°, β = 72.076(2)°, γ = 82.375(2)°) and CpCr(CO)2SN3(CCF3)(C6H4OCH3) (P21/c, a = 8.1311(7) Å, b = 24.284(2) Å, c = 9.1025(8) Å, β = 97.218(2)°), also fully characterized by spectroscopy and crystallography. Their measured Cr–S bond lengths, 2.2987(14) and 2.2965(11) Å, correspond to bond orders of 1.5. (U/R)B3PW91/6-311+G(2df,2p)//B3PW91/6-31G(2d,p) hybrid density functional theory (DFT) calculations show that the tricarbonyl complex has an unusual σ bond. However, the dicarbonyl complexes of the fluorinated thiatriazinyls are π bonded.
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Affiliation(s)
- Chwee Ying Ang
- Department of Chemistry, National University of Singapore, Kent Ridge, Singapore 117543
| | - Seah Ling Kuan
- Department of Chemistry, National University of Singapore, Kent Ridge, Singapore 117543
| | - Geok Kheng Tan
- Department of Chemistry, National University of Singapore, Kent Ridge, Singapore 117543
| | - Lai Yoong Goh
- Department of Chemistry, National University of Singapore, Kent Ridge, Singapore 117543
| | - Tracey L. Roemmele
- Department of Chemistry and Biochemistry and the Canadian Centre for Research in Advanced Fluorine Technologies, University of Lethbridge, 4401 University Dr. W, Lethbridge, AB T1K 3M4, Canada
| | - Xin Yu
- Department of Chemistry and Biochemistry and the Canadian Centre for Research in Advanced Fluorine Technologies, University of Lethbridge, 4401 University Dr. W, Lethbridge, AB T1K 3M4, Canada
| | - René T. Boeré
- Department of Chemistry and Biochemistry and the Canadian Centre for Research in Advanced Fluorine Technologies, University of Lethbridge, 4401 University Dr. W, Lethbridge, AB T1K 3M4, Canada
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21
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Rezaei Rad B, Chakraborty U, Mühldorf B, Sklorz JAW, Bodensteiner M, Müller C, Wolf R. Synthesis, Structure, and Reactivity of Pentamethylcyclopentadienyl 2,4,6-Triphenylphosphinine Iron Complexes. Organometallics 2015. [DOI: 10.1021/om501161y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Babak Rezaei Rad
- Institute
of Inorganic Chemistry, University of Regensburg, D-93040 Regensburg, Germany
| | - Uttam Chakraborty
- Institute
of Inorganic Chemistry, University of Regensburg, D-93040 Regensburg, Germany
| | - Bernd Mühldorf
- Institute
of Inorganic Chemistry, University of Regensburg, D-93040 Regensburg, Germany
| | - Julian A. W. Sklorz
- Institut
für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße
34/36, D-14195 Berlin, Germany
| | - Michael Bodensteiner
- Institute
of Inorganic Chemistry, University of Regensburg, D-93040 Regensburg, Germany
| | - Christian Müller
- Institut
für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße
34/36, D-14195 Berlin, Germany
| | - Robert Wolf
- Institute
of Inorganic Chemistry, University of Regensburg, D-93040 Regensburg, Germany
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22
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Abstract
In this paper, we reported the smallest main-group dicarbide with all deltahedras, which is also the first main-group dicarbide with (n + 1) polyhedral skeletal electron pairs (PSEPs).
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Affiliation(s)
- Jing-jing Sui
- Institute of Theoretical Chemistry
- Jilin University
- Changchun 130023
- People's Republic of China
| | - Jing Xu
- Institute of Theoretical Chemistry
- Jilin University
- Changchun 130023
- People's Republic of China
| | - Yi-hong Ding
- Institute of Theoretical Chemistry
- Jilin University
- Changchun 130023
- People's Republic of China
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23
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Chirila A, Wolf R, Chris Slootweg J, Lammertsma K. Main group and transition metal-mediated phosphaalkyne oligomerizations. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2013.10.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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24
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Rezaei Rad B, Herrmann D, Lescop C, Wolf R. A tetradentate metalloligand: synthesis and coordination behaviour of a 2-pyridyl-substituted cyclobutadiene iron complex. Dalton Trans 2014; 43:4247-50. [DOI: 10.1039/c3dt52699b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A novel cyclobutadiene iron complex with four 2-pyridyl-substitutents acts as a bis(bidentate) chelate ligand toward Zn2+ cations.
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Affiliation(s)
- Babak Rezaei Rad
- University of Regensburg
- Institute of Inorganic Chemistry
- 93040 Regensburg, Germany
| | - Dirk Herrmann
- University of Regensburg
- Institute of Inorganic Chemistry
- 93040 Regensburg, Germany
| | - Christophe Lescop
- Sciences Chimiques de Rennes UMR 6226 CNRS
- Université de Rennes 1 Campus de Beaulieu
- 35042 Rennes Cedex, France
| | - Robert Wolf
- University of Regensburg
- Institute of Inorganic Chemistry
- 93040 Regensburg, Germany
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25
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Malberg J, Wiegand T, Eckert H, Bodensteiner M, Wolf R. Copper(I) and Silver(I) Complexes of 1,3-Diphosphacyclobutadiene Sandwich Anions: Synthesis, Crystal Structures, and Solution and Solid-State NMR Spectroscopic Characterization. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201301173] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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26
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Chen X, Jin R, Du Q, Feng H, Xie Y, King RB. Iron–iron bonding versus iron–phosphorus bonding in binuclear diphosphacyclobutadiene iron carbonyl complexes. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.08.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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27
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Malberg J, Lupton E, Schnöckelborg EM, de Bruin B, Sutter J, Meyer K, Hartl F, Wolf R. Synthesis and Electronic Structure of Dissymmetrical, Naphthalene-Bridged Sandwich Complexes [Cp′Fe(μ-C10H8)MCp*]x (x = 0, +1; M = Fe, Ru; Cp′ = η5-C5H2-1,2,4-tBu3; Cp* = η5-C5Me5). Organometallics 2013. [DOI: 10.1021/om4005862] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Jennifer Malberg
- Institute of Inorganic Chemistry, University of Regensburg, 93040 Regensburg, Germany
| | - Elizabeth Lupton
- Institute of Physical and Theoretical Chemistry, University of Regensburg, 93040 Regensburg, Germany
| | | | - Bas de Bruin
- Homogeneous and Supramolecular
Catalysis, Van
‘t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Jörg Sutter
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Karsten Meyer
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - František Hartl
- Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdom
| | - Robert Wolf
- Institute of Inorganic Chemistry, University of Regensburg, 93040 Regensburg, Germany
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28
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Malberg J, Wiegand T, Eckert H, Bodensteiner M, Wolf R. Gold(I) and Silver(I) Complexes of Diphosphacyclobutadiene Cobaltate Sandwich Anions. Chemistry 2013; 19:2356-69. [DOI: 10.1002/chem.201203606] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Indexed: 11/06/2022]
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29
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Brennessel WW, Ellis JE. Naphthalene and Anthracene Cobaltates(1−): Useful Storable Sources of an Atomic Cobalt Anion. Inorg Chem 2012; 51:9076-94. [PMID: 22877417 DOI: 10.1021/ic301240u] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- William W. Brennessel
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis,
Minnesota 55455, United States
| | - John E. Ellis
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis,
Minnesota 55455, United States
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30
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Schnöckelborg EM, Khusniyarov MM, de Bruin B, Hartl F, Langer T, Eul M, Schulz S, Pöttgen R, Wolf R. Unraveling the electronic structures of low-valent naphthalene and anthracene iron complexes: X-ray, spectroscopic, and density functional theory studies. Inorg Chem 2012; 51:6719-30. [PMID: 22639983 DOI: 10.1021/ic300366m] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Naphthalene and anthracene transition metalates are potent reagents, but their electronic structures have remained poorly explored. A study of four Cp*-substituted iron complexes (Cp* = pentamethylcyclopentadienyl) now gives rare insight into the bonding features of such species. The highly oxygen- and water-sensitive compounds [K(18-crown-6){Cp*Fe(η(4)-C(10)H(8))}] (K1), [K(18-crown-6){Cp*Fe(η(4)-C(14)H(10))}] (K2), [Cp*Fe(η(4)-C(10)H(8))] (1), and [Cp*Fe(η(4)-C(14)H(10))] (2) were synthesized and characterized by NMR, UV-vis, and (57)Fe Mössbauer spectroscopy. The paramagnetic complexes 1 and 2 were additionally characterized by electron paramagnetic resonance (EPR) spectroscopy and magnetic susceptibility measurements. The molecular structures of complexes K1, K2, and 2 were determined by single-crystal X-ray crystallography. Cyclic voltammetry of 1 and 2 and spectroelectrochemical experiments revealed the redox properties of these complexes, which are reversibly reduced to the monoanions [Cp*Fe(η(4)-C(10)H(8))](-) (1(-)) and [Cp*Fe(η(4)-C(14)H(10))](-) (2(-)) and reversibly oxidized to the cations [Cp*Fe(η(6)-C(10)H(8))](+) (1(+)) and [Cp*Fe(η(6)-C(14)H(10))](+) (2(+)). Reduced orbital charges and spin densities of the naphthalene complexes 1(-/0/+) and the anthracene derivatives 2(-/0/+) were obtained by density functional theory (DFT) methods. Analysis of these data suggests that the electronic structures of the anions 1(-) and 2(-) are best represented by low-spin Fe(II) ions coordinated by anionic Cp* and dianionic naphthalene and anthracene ligands. The electronic structures of the neutral complexes 1 and 2 may be described by a superposition of two resonance configurations which, on the one hand, involve a low-spin Fe(I) ion coordinated by the neutral naphthalene or anthracene ligand L, and, on the other hand, a low-spin Fe(II) ion coordinated to a ligand radical L(•-). Our study thus reveals the redox noninnocent character of the naphthalene and anthracene ligands, which effectively stabilize the iron atoms in a low formal, but significantly higher spectroscopic oxidation state.
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Affiliation(s)
- Eva-Maria Schnöckelborg
- Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstrasse 30, 48149 Münster, Germany
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31
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Schnöckelborg E, Hartl F, Langer T, Pöttgen R, Wolf R. Redox‐Active, Dinuclear Sandwich Compounds [Cp*Fe(μ‐L)FeCp*] (L = Naphthalene and Anthracene). Eur J Inorg Chem 2012. [DOI: 10.1002/ejic.201200001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Eva‐Maria Schnöckelborg
- University of Münster, Institute of Inorganic and Analytical Chemistry, Corrensstraße 30, 48149 Münster, Germany, Fax: +49‐941‐943‐814485
| | - František Hartl
- University of Reading, Department of Chemistry, Whiteknights, Reading, RG6 6AD, United Kingdom
| | - Thorsten Langer
- University of Münster, Institute of Inorganic and Analytical Chemistry, Corrensstraße 30, 48149 Münster, Germany, Fax: +49‐941‐943‐814485
| | - Rainer Pöttgen
- University of Münster, Institute of Inorganic and Analytical Chemistry, Corrensstraße 30, 48149 Münster, Germany, Fax: +49‐941‐943‐814485
| | - Robert Wolf
- University of Münster, Institute of Inorganic and Analytical Chemistry, Corrensstraße 30, 48149 Münster, Germany, Fax: +49‐941‐943‐814485
- University of Regensburg, Institute of Inorganic Chemistry, 93040 Regensburg, Germany
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32
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Weber K, Schnöckelborg EM, Wolf R. Catalytic Properties of Low Oxidation State Iron Complexes in Cross-Coupling Reactions: Anthracene Iron(−I) Complexes as Competent Catalysts. ChemCatChem 2011. [DOI: 10.1002/cctc.201100199] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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33
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Dzik WI, Zhang XP, de Bruin B. Redox noninnocence of carbene ligands: carbene radicals in (catalytic) C-C bond formation. Inorg Chem 2011; 50:9896-903. [PMID: 21520926 DOI: 10.1021/ic200043a] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In this Forum contribution, we highlight the radical-type reactivities of one-electron-reduced Fischer-type carbenes. Carbene complexes of group 6 transition metals (Cr, Mo, and W) can be relatively easily reduced by an external reducing agent, leading to one-electron reduction of the carbene ligand moiety. This leads to the formation of "carbene-radical" ligands, showing typical radical-type reactivities. Fischer-type carbene ligands are thus clearly redox-active and can behave as so-called "redox noninnocent ligands". The "redox noninnocence" of Fischer-type carbene ligands is most clearly illustrated at group 9 transition metals in the oxidation state II+ (Co(II), Rh(II), and Ir(II)). In such carbene complexes, the metal effectively reduces the carbene ligand by one electron in an intramolecular redox process. As a result, the thus formed "carbene radicals" undergo a variety of radical-type C-C and C-H bond formations. The redox noninnocence of Fischer-type carbene ligands is not just a chemical curiosity but, in fact, plays an essential role in catalytic cyclopropanation reactions by cobalt(II) porphyrins. This has led to the successful development of new chiral cobalt(II) porphyrins as highly effective catalysts for asymmetric cyclopropanation with unprecedented reactivity and stereocontrol. The redox noninnocence of the carbene intermediates results in the formation of carbene-radical ligands with nucleophilic character, which explains their effectiveness in the cyclopropanation of electron-deficient olefins and their reduced tendency to mediate carbene dimerization. To the best of our knowledge, this represents the first example in which the redox noninnocence of a reacting ligand plays a key role in a catalytic organometallic reaction. This Forum contribution ends with an outlook on further potential applications of one-electron-activated Fischer-type carbenes in new catalytic reactions.
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Affiliation(s)
- Wojciech I Dzik
- Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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