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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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Maiola ML, Buss JA. Accessing Ta/Cu Architectures via Metal-Metal Salt Metatheses: Heterobimetallic C-H Bond Activation Affords μ-Hydrides. Angew Chem Int Ed Engl 2023; 62:e202311721. [PMID: 37831544 DOI: 10.1002/anie.202311721] [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: 08/11/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/15/2023]
Abstract
We employ a metal-metal salt metathesis strategy to access low-valent tantalum-copper heterometallic architectures (Ta-μ2 -H2 -Cu and Ta-μ3 -H2 -Cu3 ) that emulate structural elements proposed for surface alloyed nanomaterials. Whereas cluster assembly with carbonylmetalates is well precedented, the use of the corresponding polyarene transition metal anions is underexplored, despite recognition of these highly reactive fragments as storable sources of atomic Mn- . Our application of this strategy provides structurally unique early-late bimetallic species. These complexes incorporate bridging hydride ligands during their syntheses, the origin of which is elucidated via detailed isotopic labelling studies. Modification of ancillary ligand sterics and electronics alters the mechanism of bimetallic assembly; a trinuclear complex resulting from dinuclear C-H activation is demonstrated as an intermediate en route to formation of the bimetallic. Further validating the promise of this rational, bottom-up approach, a unique tetranuclear species was synthesized, featuring a Ta centre bearing three Ta-Cu interactions.
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Affiliation(s)
- Michela L Maiola
- Willard Henry Dow Laboratory, Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109, USA
| | - Joshua A Buss
- Willard Henry Dow Laboratory, Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109, USA
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3
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Young VG, Brennessel WW, Ellis JE. Crystal structure and synthesis of the bis(anthracene)dicuprate dianion as the dipotassium salt, [K(tetrahydrofuran) 2] 2[{Cu(9,10-η 2-anthracene)} 2], the first anionic arene complex of copper. Acta Crystallogr C Struct Chem 2023; 79:456-463. [PMID: 37787071 PMCID: PMC10625718 DOI: 10.1107/s2053229623008367] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 09/22/2023] [Indexed: 10/04/2023] Open
Abstract
Reactions of (tricyclohexylphosphane)copper(I) chloride with two equivalents of potassium anthracene (KAn) in tetrahydrofuran (THF) at 200 K provides air-sensitive but thermally stable (at 293 K) solutions from which yellow crystalline blocks of bis[bis(tetrahydrofuran-κO)potassium] bis(μ-anthracene-κ2C9:C10)dicopper, [K(THF)2]2[{Cu(9,10-η2-C14H10)}2] or [K(C4H8O)2]2[Cu2(C14H10)2], 1, were isolated in about 50% yield. Single-crystal X-ray crystallographic analysis of 1 confirmed the presence of the first known (arene)cuprate. Also, unlike all previously known homoleptic (anthracene)metallates of d-block elements, which contain metals coordinated only to terminal rings, the organocuprate unit in 1 contains copper bound to the 9,10-carbons of the central ring of anthracene. No other d- or f-block metal is known to afford an anthracene or other aromatic hydrocarbon complex having the architecture of organodicuprate 1.
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Affiliation(s)
- Victor G. Young
- Department of Chemistry, 207 Pleasant Street SE, University of Minnesota, Minneapolis, MN 55455, USA
| | - William W. Brennessel
- Department of Chemistry, 120 Trustee Road, University of Rochester, Rochester, NY 14627, USA
| | - John E. Ellis
- Department of Chemistry, 207 Pleasant Street SE, University of Minnesota, Minneapolis, MN 55455, USA
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Ouellette ET, Magdalenski JS, Bergman RG, Arnold J. Applications of Low-Valent Transition Metalates: Development of a Reactive Noncarbonyl Rhenium(I) Anion. Acc Chem Res 2022; 55:783-793. [PMID: 35171568 DOI: 10.1021/acs.accounts.2c00013] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Low-valent transition metalates─anionic, electronic-rich organometallic complexes─comprise a class of highly reactive chemical reagents that find integral applications in organic synthesis, small-molecule activation, transient species stabilization, and M-E bond formation, among others. The inherent reactivity of such electron-rich metal centers has necessitated the widespread use of strong backbonding ligands, particularly carbonyls, to aid in the isolation and handling of metalate reagents, albeit sometimes at the expense of partially masking their full reactivity. However, recent synthetic explorations into transition-metalate complexes devoid of archetypic back-bonding ligands have led to the discovery of highly reactive metalates capable of performing a variety of novel chemical transformations.Building on our group's long-standing interest in reactive organometallic species, a series of rational progressions in early-to-middle transition-metal chemistry ultimately led to our isolation of a rhenium(I) β-diketiminate cyclopentadienide metalate that displays exceptional reactivity. We have found this Re(I) metalate to be capable of small-molecule activation; notably, the complex reversibly binds dinitrogen in solution and can be utilized to trap N2 for the synthesis of functionalized diazenido species. By employing isolobal analogues to N2 (CO and RNC), we were able to thoroughly monitor the mechanism of activation and conclude that the metalate's sodium counterion plays an integral role in promoting dinitrogen activation through a novel side-on interaction. The Re(I) metalate is also used in forming a variety of M-E bonds, including a series of uncommon rhenium-tetrylene (Si, Ge, and Sn) complexes that display varying degrees of multiple bonding. These metal tetrylenes act to highlight deviations in chemical properties within the group 14 elements. Our metalate's utility also applies to metal-metal bond formation, as demonstrated through the synthesis of a heterotetrametallic rhenium-zinc dimer. In this reaction, the Re(I) metalate performs a dual role as a reductant and metalloligand to stabilize a transient Zn22+ core fragment. Finally, the metalate displays unique reactivity with uranium(III) to yield the first transition metal-actinide inverse-sandwich bonds, in this case with three rhenium fragments bound through their Cp moieties surrounding the uranium center. Notably, throughout these endeavors we demonstrate that the metalate displays reactivity at multiple locations, including directly at the rhenium metal center, at a Cp carbon, through a Cp-sandwich mode, or through reversibly bound dinitrogen.Overall, the rhenium(I) metalate described herein demonstrates utility in diverse applications: small-molecule activation, the stabilization of reduced and/or unstable species, and the formation of unconventional M-E/M-M bonds or heterometallic complexes. Moving forward, we suggest that the continued discovery of noncarbonyl, electron-rich transition-metal anions featuring new or unconventional ligands should produce additional reactive organometallic species capable of stabilizing unique structural motifs and performing novel and unusual chemical transformations.
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Affiliation(s)
- Erik T. Ouellette
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Julian S. Magdalenski
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Robert G. Bergman
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - John Arnold
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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5
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Murillo J, Bhowmick R, Harriman KLM, Gomez-Torres A, Wright J, Meulenberg RW, Miró P, Metta-Magaña A, Murugesu M, Vlaisavljevich B, Fortier S. Actinide arene-metalates: ion pairing effects on the electronic structure of unsupported uranium-arenide sandwich complexes. Chem Sci 2021; 12:13360-13372. [PMID: 34777754 PMCID: PMC8528047 DOI: 10.1039/d1sc03275e] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/09/2021] [Indexed: 11/21/2022] Open
Abstract
Addition of [UI2(THF)3(μ-OMe)]2·THF (2·THF) to THF solutions containing 6 equiv. of K[C14H10] generates the heteroleptic dimeric complexes [K(18-crown-6)(THF)2]2[U(η6-C14H10)(η4-C14H10)(μ-OMe)]2·4THF (118C6·4THF) and {[K(THF)3][U(η6-C14H10)(η4-C14H10)(μ-OMe)]}2 (1THF) upon crystallization of the products in THF in the presence or absence of 18-crown-6, respectively. Both 118C6·4THF and 1THF are thermally stable in the solid-state at room temperature; however, after crystallization, they become insoluble in THF or DME solutions and instead gradually decompose upon standing. X-ray diffraction analysis reveals 118C6·4THF and 1THF to be structurally similar, possessing uranium centres sandwiched between bent anthracenide ligands of mixed tetrahapto and hexahapto ligation modes. Yet, the two complexes are distinguished by the close contact potassium-arenide ion pairing that is seen in 1THF but absent in 118C6·4THF, which is observed to have a significant effect on the electronic characteristics of the two complexes. Structural analysis, SQUID magnetometry data, XANES spectral characterization, and computational analyses are generally consistent with U(iv) formal assignments for the metal centres in both 118C6·4THF and 1THF, though noticeable differences are detected between the two species. For instance, the effective magnetic moment of 1THF (3.74 μB) is significantly lower than that of 118C6·4THF (4.40 μB) at 300 K. Furthermore, the XANES data shows the U LIII-edge absorption energy for 1THF to be 0.9 eV higher than that of 118C6·4THF, suggestive of more oxidized metal centres in the former. Of note, CASSCF calculations on the model complex {[U(η6-C14H10)(η4-C14H10)(μ-OMe)]2}2− (1*) shows highly polarized uranium–arenide interactions defined by π-type bonds where the metal contributions are primarily comprised by the 6d-orbitals (7.3 ± 0.6%) with minor participation from the 5f-orbitals (1.5 ± 0.5%). These unique complexes provide new insights into actinide–arenide bonding interactions and show the sensitivity of the electronic structures of the uranium atoms to coordination sphere effects. Use of Chatt metal-arene protocols with uranium leads to the synthesis of the first well-characterized, unsupported actinide–arenide sandwich complexes. The electronic structures of the actinide centres show a key sensitivity to ion pairing effects.![]()
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Affiliation(s)
- Jesse Murillo
- Department of Chemistry and Biochemistry, University of Texas at El Paso El Paso Texas 79968 USA
| | - Rina Bhowmick
- Department of Chemistry, University of South Dakota Vermillion South Dakota 57069 USA
| | - Katie L M Harriman
- Department of Chemistry and Biomolecular Sciences, University of Ottawa Ottawa Ontario K1N 6N5 Canada
| | - Alejandra Gomez-Torres
- Department of Chemistry and Biochemistry, University of Texas at El Paso El Paso Texas 79968 USA
| | - Joshua Wright
- Department of Physics, Illinois Institute of Technology Chicago Illinois 60616 USA
| | - Robert W Meulenberg
- Department of Physics and Astronomy and Frontier Institute for Research in Sensor Technologies, University of Maine Orono Maine 04469 USA
| | - Pere Miró
- Department of Chemistry, University of South Dakota Vermillion South Dakota 57069 USA
| | - Alejandro Metta-Magaña
- Department of Chemistry and Biochemistry, University of Texas at El Paso El Paso Texas 79968 USA
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa Ottawa Ontario K1N 6N5 Canada
| | - Bess Vlaisavljevich
- Department of Chemistry, University of South Dakota Vermillion South Dakota 57069 USA
| | - Skye Fortier
- Department of Chemistry and Biochemistry, University of Texas at El Paso El Paso Texas 79968 USA
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6
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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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7
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Han J, Grofe A, Gao J. Variational Energy Decomposition Analysis of Charge-Transfer Interactions between Metals and Ligands in Carbonyl Complexes. Inorg Chem 2021; 60:14060-14071. [PMID: 34460236 DOI: 10.1021/acs.inorgchem.1c01367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Variational energy decomposition analyses have been presented to quantify the σ-dative, ligand-to-metal forward charge transfer (CT) and the π-conjugative, metal-to-ligand backward charge delocalization on a series of isolelectronic transition-metal carbonyl complexes M(CO)6, including M = Ti2-, V-, Cr, Mn+, and Fe2+. Although the qualitative features of these energy terms are understood, well-defined quantitative studies have been scarce. Consistent with early findings, electrostatic and Pauli exchange effects play a key role in σ-donation, resulting in blue shifts in ligand vibrational frequency in the complex geometries. Excluding chemical bonding interactions between the CO ligand and the metal fragments in the energy decomposition analysis, we found that loosely bound electrostatic complexes can be formed at a longer metal-to-ligand distance due to the exponential decay of Pauli exchange. In all complexes, the overall binding stabilization can be attributed to CT effects, with opposing trends between σ-donation and π-back bonding that follows an order of Ti2- (4.4) > V1- (2.6) > Cr (1.5) > Mn1+ (1.1) > Fe2+ (0.5) in π-to-σ CT ratio. These electronic and energetic features are mirrored in the vibrational frequency shifts induced by different factors. The present investigation may help stimulate the use of energy decomposition techniques to understand the structure and activity of metallocatalysts using density functional theory.
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Affiliation(s)
- Jingting Han
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin Province 130023, China
| | - Adam Grofe
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, Jilin Province 130023, China.,Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518055, China
| | - Jiali Gao
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518055, China.,Beijing University Shenzhen Graduate School, Shenzhen 518055, China.,Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455, United States
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8
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Ghana P, Schrader S, Rajeshkumar T, Spaniol TP, Englert U, Maron L, Okuda J. Reduced Arene Complexes of Hafnium Supported by a Triamidoamine Ligand. Angew Chem Int Ed Engl 2021; 60:14179-14187. [PMID: 33890350 PMCID: PMC8252659 DOI: 10.1002/anie.202103755] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Indexed: 11/09/2022]
Abstract
A series of hafnium complexes with a reduced arene of the general formula [K(L)][Hf(Xy-N3 N)(arene)] (Xy-N3 N={(3,5-Me2 C6 H3 )NCH2 CH2 }3 N3- , L=THF, 18-crown-6; arene=C10 H8 2- , C14 H10 2- ) mimic the chemistry of hafnium in its formal oxidation state +II. All compounds were obtained upon reduction of the chlorido complex [HfCl(Xy-N3 N)(thf)] with two equivalents of potassium naphthalenide or anthracenide. The reducing nature and the basicity of the reduced anthracene ligand were explored in the reaction of benzonitrile and azobenzene, and by deprotonation of tert-butylacetylene, respectively. The reduction of benzonitrile provides an initial double nitrile insertion product under kinetic control that rearranges after extrusion of one of the inserted nitriles to a hafnium imido complex as the thermodynamic product. The reduction of azobenzene resulted in a diphenylhydrazido(2-) complex. Treatment of terminal alkynes with the anthracene or diphenylhydrazido(2-) complex led to the selective protonation of the corresponding dianionic ligand.
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Affiliation(s)
- Priyabrata Ghana
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Sebastian Schrader
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Thayalan Rajeshkumar
- Université de Toulouse et CNRSINSAUPSUMR 5215LPCNO135 Avenue de RangueilF-31077ToulouseFrance
| | - Thomas P. Spaniol
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Ulli Englert
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Laurent Maron
- Université de Toulouse et CNRSINSAUPSUMR 5215LPCNO135 Avenue de RangueilF-31077ToulouseFrance
| | - Jun Okuda
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
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Ghana P, Schrader S, Rajeshkumar T, Spaniol TP, Englert U, Maron L, Okuda J. Reduzierte Arenkomplexe von Hafnium mit einem Triamidoaminliganden. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103755] [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]
Affiliation(s)
- Priyabrata Ghana
- Institut für anorganische Chemie RWTH Aachen Landoltweg 1 52056 Aachen Deutschland
| | - Sebastian Schrader
- Institut für anorganische Chemie RWTH Aachen Landoltweg 1 52056 Aachen Deutschland
| | - Thayalan Rajeshkumar
- Université de Toulouse et CNRS INSA UPS UMR 5215 LPCNO 135 Avenue de Rangueil F-31077 Toulouse Frankreich
| | - Thomas P. Spaniol
- Institut für anorganische Chemie RWTH Aachen Landoltweg 1 52056 Aachen Deutschland
| | - Ulli Englert
- Institut für anorganische Chemie RWTH Aachen Landoltweg 1 52056 Aachen Deutschland
| | - Laurent Maron
- Université de Toulouse et CNRS INSA UPS UMR 5215 LPCNO 135 Avenue de Rangueil F-31077 Toulouse Frankreich
| | - Jun Okuda
- Institut für anorganische Chemie RWTH Aachen Landoltweg 1 52056 Aachen Deutschland
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10
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Abstract
Alkali metal naphthalenide or anthracenide reacted with scandium(III) anilides [Sc(X){N(tBu)Xy}2 (thf)] (X=N(tBu)Xy (1); X=Cl (2); Xy=C6 H3 -3,5-Me2 ) to give scandium complexes [M(thf)n ][Sc{N(tBu)Xy}2 (RA)] (M=Li-K; n=1-6; RA=C10 H8 2- (3-Naph-K) and C14 H10 2- (3-Anth-M)) containing a reduced arene ligand. Single-crystal X-ray diffraction revealed the scandium(III) center bonded to the naphthalene dianion in a σ2 :π-coordination mode, whereas the anthracene dianion is symmetrically attached to the scandium(III) center in a σ2 -fashion. All compounds have been characterized by multinuclear, including 45 Sc NMR spectroscopy. Quantum chemical calculations of these intensely colored arene complexes confirm scandium to be in the oxidation state +3. The intense absorptions observed in the UV/Vis spectra are due to ligand-to-metal charge transfers. Whereas nitriles underwent C-C coupling reaction with the reduced arene ligand, the reaction with one equivalent of [NEt3 H][BPh4 ] led to the mono-protonation of the reduced arene ligand.
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Affiliation(s)
- Priyabrata Ghana
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Alexander Hoffmann
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Thomas P. Spaniol
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Jun Okuda
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
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11
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Maier TM, Sandl S, Melzl P, Zweck J, Jacobi von Wangelin A, Wolf R. Heterogeneous Olefin Hydrogenation Enabled by a Highly-Reduced Nickel(-II) Catalyst Precursor. Chemistry 2020; 26:6113-6117. [PMID: 32034810 PMCID: PMC7318650 DOI: 10.1002/chem.201905537] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 02/03/2020] [Indexed: 12/21/2022]
Abstract
The hydrogenation of olefins, styrenes, enoates, imines, and sterically hindered tri-substituted olefins was accomplished using the pre-catalyst dilithiumbis(cycloocta-1,5-diene)nickelate(-II) (1). The mild conditions tolerate hydroxyl, halide, ester, and lactone functionalities. Mechanistic studies, including reaction progress analyses, poisoning experiments, and multinuclear NMR monitoring, indicate that a heterotopic (nickel nanoparticle) catalyst is in operation.
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Affiliation(s)
- Thomas M. Maier
- University of RegensburgInstitute of Inorganic Chemistry93040RegensburgGermany
| | - Sebastian Sandl
- University of HamburgDepartment of Chemistry20146HamburgGermany
| | - Peter Melzl
- University of RegensburgInstitute of Experimental and Applied Physics93040RegensburgGermany
| | - Josef Zweck
- University of RegensburgInstitute of Experimental and Applied Physics93040RegensburgGermany
| | | | - Robert Wolf
- University of RegensburgInstitute of Inorganic Chemistry93040RegensburgGermany
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12
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Sandl S, Jacobi von Wangelin A. The Role of Organoferrates in Iron-Catalyzed Cross-Couplings. Angew Chem Int Ed Engl 2020; 59:5434-5437. [PMID: 31999050 DOI: 10.1002/anie.201914844] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Indexed: 02/06/2023]
Abstract
Recent groundbreaking studies on organoferrates have demonstrated that coordinatively unsaturated three-coordinate-σ-alkylferrates are active catalysts in Fe-catalyzed cross-couplings with Grignard reagents and that pronounced solvent and counterion effects dictate metalate speciation and catalyst activity. Thanks to modern spectroscopic methods, sensitive catalyst intermediates could be analyzed.
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Affiliation(s)
- Sebastian Sandl
- Department of Chemistry, University of Hamburg, Martin Luther King Platz 6, 20146, Hamburg, Germany
| | - Axel Jacobi von Wangelin
- Department of Chemistry, University of Hamburg, Martin Luther King Platz 6, 20146, Hamburg, Germany
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13
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14
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Wilson ASS, Dinoi C, Hill MS, Mahon MF, Maron L, Richards E. Calcium Hydride Reduction of Polycyclic Aromatic Hydrocarbons. Angew Chem Int Ed Engl 2019; 59:1232-1237. [DOI: 10.1002/anie.201913895] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Indexed: 11/09/2022]
Affiliation(s)
| | - Chiara Dinoi
- Université de Toulouse et CNRS INSA UPS, UMR 5215 LPCNO 135 Avenue de Rangueil 31077 Toulouse France
| | | | - Mary F. Mahon
- Department of Chemistry University of Bath Bath BA2 7AY UK
| | - Laurent Maron
- Université de Toulouse et CNRS INSA UPS, UMR 5215 LPCNO 135 Avenue de Rangueil 31077 Toulouse France
| | - Emma Richards
- School of Chemistry Cardiff University Park Place Cardiff CF10 3AT UK
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Wilson ASS, Dinoi C, Hill MS, Mahon MF, Maron L, Richards E. Calcium Hydride Reduction of Polycyclic Aromatic Hydrocarbons. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201913895] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Chiara Dinoi
- Université de Toulouse et CNRS INSA UPS, UMR 5215 LPCNO 135 Avenue de Rangueil 31077 Toulouse France
| | | | - Mary F. Mahon
- Department of Chemistry University of Bath Bath BA2 7AY UK
| | - Laurent Maron
- Université de Toulouse et CNRS INSA UPS, UMR 5215 LPCNO 135 Avenue de Rangueil 31077 Toulouse France
| | - Emma Richards
- School of Chemistry Cardiff University Park Place Cardiff CF10 3AT UK
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16
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Maier TM, Coburger P, van Leest NP, Hey-Hawkins E, Wolf R. Direct synthesis of an anionic 13-vertex closo-cobaltacarborane cluster. Dalton Trans 2019; 48:15772-15777. [PMID: 31612881 DOI: 10.1039/c9dt03111a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Reaction of 1,2-bis(diphenylphosphino)-ortho-carborane (L) with [K(thf){(MesBIAN)Co(η4-cod)}] (1, MesBIAN = bis(mesityliminoace-naphthene)diimine, cod = 1,5-cyclooctadiene) affords an anionic 13-vertex closo-cobaltacarborane cluster (2) in one step. The mechanism of this transformation has been studied by experimental and quantum chemical techniques, which suggest that a series of outer-sphere electron transfer and isomerisation processes occurs. This work shows that low-valent metalate anions are promising reagents for the synthesis of anionic metallacarborane clusters.
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Affiliation(s)
- Thomas M Maier
- University of Regensburg, Institute of Inorganic Chemistry, 93040 Regensburg, Germany.
| | - Peter Coburger
- University of Regensburg, Institute of Inorganic Chemistry, 93040 Regensburg, Germany. and Leipzig University, Institute of Inorganic Chemistry, Johannisallee 29, 04103 Leipzig, Germany.
| | - Nicolaas P van Leest
- Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam (UvA) Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Evamarie Hey-Hawkins
- Leipzig University, Institute of Inorganic Chemistry, Johannisallee 29, 04103 Leipzig, Germany.
| | - Robert Wolf
- University of Regensburg, Institute of Inorganic Chemistry, 93040 Regensburg, Germany.
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