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Zafar M, Subramaniyan V, Tibika F, Tulchinsky Y. Cationic ligands - from monodentate to pincer systems. Chem Commun (Camb) 2024. [PMID: 38920056 DOI: 10.1039/d4cc01489h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
For a long time, the small group of cationic ligands stood out as obscure systems within the general landscape of coordinative chemistry. However, this situation has started to change rapidly during the last decade, with more and more examples of metal-coordinated cationic species being reported. The growing interest in these systems is not only of purely academic nature, but also driven by accumulating evidence of their high catalytic utility. Overcoming the inherently poor coordinating ability of cationic species often required additional structural stabilization. In numerous cases this was realized by functionalizing them with a pair of chelating side-arms, effectively constructing a pincer-type scaffold. This comprehensive review aims to encompass all cationic ligands possessing such pincer architecture reported to date. Herein every cationic species that has ever been embedded in a pincer framework is described in terms of its electronic structure, followed by an in-depth discussion of its donor/acceptor properties, based on computational studies (DFT) and available experimental data (IR, NMR or CV). We then elaborate on how the positive charge of these ligands affects the spectroscopic and redox properties, as well as the reactivity, of their complexes, compared to those of the structurally related neutral ligands. Among other systems discussed, this review also surveys our own contribution to this field, namely, the introduction of sulfonium-based pincer ligands and their complexes, recently reported by our group.
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Affiliation(s)
- Mohammad Zafar
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
| | | | - Françoise Tibika
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
| | - Yuri Tulchinsky
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
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2
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Mast M, Schubert H, Mayer HA, Wesemann L. Trianionic Carbocyclic NCN Pincer Ligand: Coordination Chemistry and Reactivity Studies. Inorg Chem 2024; 63:10860-10870. [PMID: 38804041 DOI: 10.1021/acs.inorgchem.4c01602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
(BCHT-NCN)H3 (1) [1,6-bis(methylene(bis-2,6-diisopropylaniline)(benzo)cycloheptatriene)] was synthesized by nucleophilic substitution treating 1,6-bis(methylenebromide)(benzo)cycloheptatriene with 2 equiv of Li[2,6-iPr2C6H3NH], Li[Dipp-NH]. Triple deprotonation of (BCHT-NCN)H3 (1) using n-BuLi yields the deprotonation product [(BCHT-NCN)Li3] (2), which crystallizes as a dimer [{[BCHT-NCN]Li3(Et2O)2}2] (2)2. Coordination compounds of the trianionic pincer ligand were obtained with SnCl2, YCl3(THF)3.5, and HfCl4(THF)2: [(BCHT-NCN)SnLi] (3), [(BCHT-NCN)Y(THF)2] (4), [(BCHT-NCN)HfCl2][Li(THF)4] (5), respectively. A hafnium hydride complex [(BCHT-NCN)HfH(HBEt3)][K(Et2O)2] (6) was isolated after reaction of 5 with K[HBEt3]. A MeNHC substitution product [(BCHT-NCN)HfCl(MeNHC)] (7) was synthesized treating compound 5 with MeNHC at rt. Following an n-BuLi reaction of 7 gives an alkyl complex [(BCHT-NCN)Hf(n-Bu)(MeNHC)] (8). Thermolysis of 7 yields the isomerization product [(BCHT-NCN#)HfCl(MeNHC)] (9), which was transferred into a methyl complex [(BCHT-NCN#)HfMe(MeNHC)] (10) upon treatment with MeMgBr. Hydride abstraction from complex 9 leads to a cationic complex [(BCHT-NCN+)HfCl(MeNHC)][Al(OtBuF)4] (11).
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Affiliation(s)
- Maximilian Mast
- Institut für Anorganische Chemie, Eberhard Karls Universität, Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
| | - Hartmut Schubert
- Institut für Anorganische Chemie, Eberhard Karls Universität, Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
| | - Hermann A Mayer
- Institut für Anorganische Chemie, Eberhard Karls Universität, Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
| | - Lars Wesemann
- Institut für Anorganische Chemie, Eberhard Karls Universität, Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany
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Kishino M, Takaoka S, Shibutani Y, Kusumoto S, Nozaki K. Synthesis and reactivity of PC(sp 3)P-pincer iridium complexes bearing a diborylmethyl anion. Dalton Trans 2022; 51:5009-5015. [PMID: 35296874 DOI: 10.1039/d2dt00513a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Novel PCP-pincer iridium complexes bearing a diborylmethyl anion were synthesized. Strong σ-electron-donation to the metal and significant π-backdonation from the metal to boron atoms at the β-position were observed both experimentally and computationally. H/D exchange of the aromatic C-H bond proceeded smoothly and, in addition, the α-methine-hydrogen between boron atoms was found to be replaced with deuterium in benzene-d6 solution possibly through diborylcarbene metal complexes as intermediates.
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Affiliation(s)
- Masamichi Kishino
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
| | - Satoko Takaoka
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
| | - Yuki Shibutani
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
| | - Shuhei Kusumoto
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
| | - Kyoko Nozaki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
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Wiedmaier NR, Schubert H, Mayer HA, Wesemann L. Carbocyclic pincer carbene complexes of ruthenium: syntheses and reversible hydrogenation. Dalton Trans 2021; 50:11814-11820. [PMID: 34369545 DOI: 10.1039/d1dt02266k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The ruthenium carbene pincer complex 2 was synthesized treating the benzo annulated cycloheptatriene bisphosphine 1 with RuCl3. Addition of three equivalents of hydrogen to the carbocyclic carbene complex 2 was achieved in reaction of 2 with hydrogen at elevated temperatures. Hydrogenated complex 4, exhibiting a rigid chair conformation in solution, was dehydrogenated by heating a toluene solution of complex 4 to reflux for 5-7 d. In reaction with ethylene, complex 4 transfers one equivalent of hydrogen, forming ethane and alkyl complex 5.
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Affiliation(s)
- Nicholas R Wiedmaier
- Institut für Anorganische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
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Wiedmaier NR, Speth H, Leistikow G, Eichele K, Schubert H, Mayer HA, Wesemann L. Conformation controlled stepwise hydride shuffling from the metal to the ligand backbone. Dalton Trans 2020; 49:7218-7227. [DOI: 10.1039/d0dt01431a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The protonation of the benzo annulated cycloheptatriene PCP pincer ruthenium hydrido dicarbonyl complex using the superacid [H(Et2O)2][BArF24] launches a cascade of hydride shifts which lead to the hydrogenation of the ligand backbone.
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Affiliation(s)
| | - Hansjörg Speth
- Institut für Anorganische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
| | - Georg Leistikow
- Institut für Anorganische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
| | - Klaus Eichele
- Institut für Anorganische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
| | - Hartmut Schubert
- Institut für Anorganische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
| | - Hermann A. Mayer
- Institut für Anorganische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
| | - Lars Wesemann
- Institut für Anorganische Chemie
- Universität Tübingen
- 72076 Tübingen
- Germany
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Reitsamer C, Schlapp-Hackl I, Partl G, Schuh W, Kopacka H, Wurst K, Peringer P. Crystal structure of an iridium(III) complex of the [C(dppm) 2] PCP pincer ligand system and its conjugate CH acid form. Acta Crystallogr E Crystallogr Commun 2018; 74:620-624. [PMID: 29850078 PMCID: PMC5947474 DOI: 10.1107/s2056989018004905] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 03/26/2018] [Indexed: 11/22/2022]
Abstract
The crystal structures of [IrIII(CO)(C(dppm)2-κ3P,C,P′)ClH]Cl and [IrIII(CO)(CH(dppm)2-κ3P,C,P′)ClH]Cl2 have been determined. Both complexes show a slightly distorted octahedral coordinated IrIII centre. The PCP pincer ligand system is arranged in a meridional manner. After the successful creation of the newly designed PCP carbodiphosphorane (CDP) ligand [Reitsamer et al. (2012 ▸). Dalton Trans.41, 3503–3514; Stallinger et al. (2007 ▸). Chem. Commun. pp. 510–512], the treatment of this PCP pincer system with the transition metal iridium and further the analysis of the structures by single-crystal diffraction and by NMR spectroscopy were of major interest. Two different iridium complexes, namely (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}methane-κ3P,C,P′)carbonylchloridohydridoiridium(III) chloride dichloromethane trisolvate, [IrIII(CO){C(dppm)2-κ3P,C,P′}ClH]Cl·3CH2Cl2 (1) and the closely related (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}methanide(1+)-κ3P,C,P′)carbonylchloridohydridoiridium(III) dichloride–hydrochloric acid–water (1/2/5.5), [IrIII(CO){CH(dppm)2-κ3P,C,P′)ClH]Cl}2 (2), have been designed and both complexes show a slightly distorted octahedral coordinated IrIII centre. The PCP pincer ligand system is arranged in a meridional manner, the CO ligand is located trans to the central PCP carbon and a hydride and chloride are located perpendicular above and below the P2C2 plane. With an Ir—CCDP distance of 2.157 (5) Å, an Ir—CO distance of 1.891 (6) Å and a quite short C—O distance of 1.117 (7) Å, complex 1 presents a strong carbonyl bond. Complex 2, the corresponding CH acid of 1, shows an additionally attached proton at the carbodiphosphorane carbon atom located antiperiplanar to the hydride of the metal centre. In comparison with complex 1, the Ir—CCDP distance of 2.207 (3) Å is lengthened and the Ir—C—O values indicate a weaker trans influence of the central carbodiphosphorane carbon atom.
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9
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Abstract
Transition metal hydride complexes are usually amphoteric, not only acting as hydride donors, but also as Brønsted-Lowry acids. A simple additive ligand acidity constant equation (LAC for short) allows the estimation of the acid dissociation constant Ka(LAC) of diamagnetic transition metal hydride and dihydrogen complexes. It is remarkably successful in systematizing diverse reports of over 450 reactions of acids with metal complexes and bases with metal hydrides and dihydrogen complexes, including catalytic cycles where these reactions are proposed or observed. There are links between pKa(LAC) and pKa(THF), pKa(DCM), pKa(MeCN) for neutral and cationic acids. For the groups from chromium to nickel, tables are provided that order the acidity of metal hydride and dihydrogen complexes from most acidic (pKa(LAC) -18) to least acidic (pKa(LAC) 50). Figures are constructed showing metal acids above the solvent pKa scales and organic acids below to summarize a large amount of information. Acid-base features are analyzed for catalysts from chromium to gold for ionic hydrogenations, bifunctional catalysts for hydrogen oxidation and evolution electrocatalysis, H/D exchange, olefin hydrogenation and isomerization, hydrogenation of ketones, aldehydes, imines, and carbon dioxide, hydrogenases and their model complexes, and palladium catalysts with hydride intermediates.
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Affiliation(s)
- Robert H Morris
- Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
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10
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Arras J, Speth H, Mayer HA, Wesemann L. Different Coordination Modes of the Ph2PCsp3PPh2 Pincer Ligand in Rhodium Complexes as a Consequence of Csp3–H Metal Interaction. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00437] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Janet Arras
- Institut für Anorganische
Chemie, Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
| | - Hansjörg Speth
- Institut für Anorganische
Chemie, Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
| | - Hermann A. Mayer
- Institut für Anorganische
Chemie, Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
| | - Lars Wesemann
- Institut für Anorganische
Chemie, Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
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11
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Fuku-en SI, Yamamoto J, Kojima S, Yamamoto Y. Synthesis and Application of New Dipyrido-annulated N-Heterocyclic Carbene with Phosphorus Substituents. CHEM LETT 2014. [DOI: 10.1246/cl.131074] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Shin-ichi Fuku-en
- Department of Chemistry, Graduate School of Science, Hiroshima University
| | - Junki Yamamoto
- Department of Chemistry, Graduate School of Science, Hiroshima University
| | - Satoshi Kojima
- Department of Chemistry, Graduate School of Science, Hiroshima University
| | - Yohsuke Yamamoto
- Department of Chemistry, Graduate School of Science, Hiroshima University
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12
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Leis W, Wernitz S, Reichart B, Ruckerbauer D, Wielandt JW, Mayer HA. Benzo annulated cycloheptatriene PCP pincer iridium complexes. Dalton Trans 2014; 43:12187-99. [DOI: 10.1039/c4dt00885e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chemical conversions of a cycloheptatriene iridium pincer complex were studied by NMR and MS techniques as well as DFT calculations.
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Affiliation(s)
- Wolfgang Leis
- Institute of Inorganic Chemistry
- University of Tuebingen
- 72076 Tuebingen, Germany
| | - Sophie Wernitz
- Institute of Inorganic Chemistry
- University of Tuebingen
- 72076 Tuebingen, Germany
| | - Benedikt Reichart
- Institut für Chemie – Bereich Anorganik
- Karl-Franzens-Universität Graz
- 8010 Graz, Austria
| | - David Ruckerbauer
- Institut für Chemie – Bereich Anorganik
- Karl-Franzens-Universität Graz
- 8010 Graz, Austria
| | | | - Hermann A. Mayer
- Institute of Inorganic Chemistry
- University of Tuebingen
- 72076 Tuebingen, Germany
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13
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Musa S, Filippov OA, Belkova NV, Shubina ES, Silantyev GA, Ackermann L, Gelman D. Ligand-Metal Cooperating PC(sp3)P Pincer Complexes as Catalysts in Olefin Hydroformylation. Chemistry 2013; 19:16906-9. [DOI: 10.1002/chem.201303311] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Indexed: 11/10/2022]
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14
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Gelman D, Romm R. PC(sp 3)P Transition Metal Pincer Complexes: Properties and Catalytic Applications. TOP ORGANOMETAL CHEM 2013. [DOI: 10.1007/978-3-642-31081-2_10] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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15
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Wingard LA, Finniss MC, Norris M, White PS, Brookhart M, Templeton JL. Synthesis, Structure, and Reactivity of Iridium(III) Complexes Containing a 4,6-Dimethyl-1,3-benzenediphenylimine Pincer Ligand. Inorg Chem 2012; 52:515-26. [DOI: 10.1021/ic302589b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Leah A. Wingard
- W. R.
Kenan Laboratory, Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
27599-3290, United States
| | - Mathew C. Finniss
- W. R.
Kenan Laboratory, Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
27599-3290, United States
| | - Michael Norris
- W. R.
Kenan Laboratory, Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
27599-3290, United States
| | - Peter S. White
- W. R.
Kenan Laboratory, Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
27599-3290, United States
| | - Maurice Brookhart
- W. R.
Kenan Laboratory, Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
27599-3290, United States
| | - Joseph L. Templeton
- W. R.
Kenan Laboratory, Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
27599-3290, United States
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Mantas-Öktem K, Öfele K, Pöthig A, Bechlars B, Herrmann WA, Kühn FE. Reactions of Nitrogen Donors with Cycloheptatrienylidene Complexes: Metal Coordination versus Nucleophilic Attack on the Carbene Ligand. Organometallics 2012. [DOI: 10.1021/om300867g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kevser Mantas-Öktem
- Chair of Inorganic Chemistry/Molecular
Catalysis, Catalysis
Research Center, Technische Universität München, Ernst-Otto-Fischer-Strasse 1, D-85747 Garching b. München,
Germany
| | - Karl Öfele
- Chair of Inorganic Chemistry/Molecular
Catalysis, Catalysis
Research Center, Technische Universität München, Ernst-Otto-Fischer-Strasse 1, D-85747 Garching b. München,
Germany
| | - Alexander Pöthig
- Chair of Inorganic Chemistry/Molecular
Catalysis, Catalysis
Research Center, Technische Universität München, Ernst-Otto-Fischer-Strasse 1, D-85747 Garching b. München,
Germany
| | - Bettina Bechlars
- Chair of Inorganic Chemistry/Molecular
Catalysis, Catalysis
Research Center, Technische Universität München, Ernst-Otto-Fischer-Strasse 1, D-85747 Garching b. München,
Germany
| | - Wolfgang A. Herrmann
- Chair of Inorganic Chemistry/Molecular
Catalysis, Catalysis
Research Center, Technische Universität München, Ernst-Otto-Fischer-Strasse 1, D-85747 Garching b. München,
Germany
| | - Fritz E. Kühn
- Chair of Inorganic Chemistry/Molecular
Catalysis, Catalysis
Research Center, Technische Universität München, Ernst-Otto-Fischer-Strasse 1, D-85747 Garching b. München,
Germany
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17
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Gelman D, Musa S. Coordination Versatility of sp3-Hybridized Pincer Ligands toward Ligand–Metal Cooperative Catalysis. ACS Catal 2012. [DOI: 10.1021/cs3005083] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dmitri Gelman
- Institute of Chemistry, The Hebrew University, Edmund Safra Campus, 91904 Jerusalem,
Israel
| | - Sanaa Musa
- Institute of Chemistry, The Hebrew University, Edmund Safra Campus, 91904 Jerusalem,
Israel
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18
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Affiliation(s)
- Clarite Azerraf
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904 Israel
| | - Dmitri Gelman
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904 Israel
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19
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Öfele K, Tosh E, Taubmann C, Herrmann WA. Carbocyclic Carbene Metal Complexes. Chem Rev 2009; 109:3408-44. [DOI: 10.1021/cr800516g] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K. Öfele
- TU München, Chemie, Lichtenbergstr. 4, Garching D-85747, Germany
| | - E. Tosh
- TU München, Chemie, Lichtenbergstr. 4, Garching D-85747, Germany
| | - C. Taubmann
- TU München, Chemie, Lichtenbergstr. 4, Garching D-85747, Germany
| | - W. A. Herrmann
- TU München, Chemie, Lichtenbergstr. 4, Garching D-85747, Germany
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20
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Arunachalampillai A, Olsson D, Wendt OF. Synthesis and characterisation of PCsp3P phosphine and phosphinite iridium complexes. Cyclometallation and dehydrogenation of a cyclohexyl ring. Dalton Trans 2009:8626-30. [DOI: 10.1039/b910798c] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Azerraf C, Gelman D. Exploring the Reactivity of C(sp3)-Cyclometalated IrIIICompounds in Hydrogen Transfer Reactions. Chemistry 2008; 14:10364-8. [DOI: 10.1002/chem.200801728] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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22
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Winter AM, Eichele K, Mack HG, Kaska WC, Mayer HA. Prototropic rearrangements in cycloheptatrienyl PCP pincer iridium complexes. Dalton Trans 2008:527-32. [DOI: 10.1039/b712712j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Bonnet S, Lutz M, Spek AL, Koten GV, Klein Gebbink RJM. η6-Coordination of a Ruthenium(II) Organometallic Fragment to the Arene Ring of N,C,N-Pincer Metal Complexes. Organometallics 2007. [DOI: 10.1021/om7009649] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sylvestre Bonnet
- Chemical Biology & Organic Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands, and Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Martin Lutz
- Chemical Biology & Organic Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands, and Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Anthony L. Spek
- Chemical Biology & Organic Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands, and Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Gerard van Koten
- Chemical Biology & Organic Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands, and Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Robertus J. M. Klein Gebbink
- Chemical Biology & Organic Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands, and Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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24
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Baratta W, Ballico M, Del Zotto A, Zangrando E, Rigo P. CH Activation and CC Double Bond Formation Reactions in Iridiumortho-Methyl Arylphosphane Complexes. Chemistry 2007; 13:6701-9. [PMID: 17535000 DOI: 10.1002/chem.200700349] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The Vaska-type iridium(I) complex [IrCl(CO){PPh(2)(2-MeC(6)H(4))}(2)] (1), characterized by an X-ray diffraction study, was obtained from iridium(III) chloride hydrate and PPh(2)(2,6-MeRC(6)H(3)) with R=H in DMF, whereas for R=Me, activation of two ortho-methyl groups resulted in the biscyclometalated iridium(III) compound [IrCl(CO){PPh(2)(2,6-CH(2)MeC(6)H(3))}(2)] (2). Conversely, for R=Me the iridium(I) compound [IrCl(CO){PPh(2)(2,6-Me(2)C(6)H(3))}(2)] (3) can be obtained by treatment of [IrCl(COE)(2)](2) (COE=cyclooctene) with carbon monoxide and the phosphane in acetonitrile. Compound 3 in CH(2)Cl(2) undergoes intramolecular C-H oxidative addition, affording the cyclometalated hydride iridium(III) species [IrHCl(CO){PPh(2)(2,6-CH(2)MeC(6)H(3))}{PPh(2)(2,6-Me(2)C(6)H(3))}] (4). Treatment of 2 with Na[BAr(f) (4)] (Ar(f)=3,5-C(6)H(3)(CF(3))(2)) gives the fluxional cationic 16-electron complex [Ir(CO){PPh(2)(2,6-CH(2)MeC(6)H(3))}(2)][BAr(f) (4)] (5), which reversibly reacts with dihydrogen to afford the delta-agostic complex [IrH(CO){PPh(2)(2,6-CH(2)MeC(6)H(3))}{PPh(2)(2,6-Me(2)C(6)H(3))}][BAr(f)(4)] (6), through cleavage of an Ir-C bond. This species can also be formed by treatment of 4 with Na[BAr(f)(4)] or of 2 with Na[BAr(f)(4)] through C-H oxidative addition of one ortho-methyl group, via a transient 14-electron iridium(I) complex. Heating of the coordinatively unsaturated biscyclometalated species 5 in toluene gives the trans-dihydride iridium(III) complex [IrH(2)(CO){PPh(2)(2,6-MeC(6)H(3)CH=CHC(6)H(3)Me-2,6)PPh(2)}][BAr(f) (4)] (7), containing a trans-stilbene-type terdentate ligand, as result of a dehydrogenative carbon-carbon double bond coupling reaction, possibly through an iridium carbene species.
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Affiliation(s)
- Walter Baratta
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Udine, Via Cotonificio 108, 33100 Udine, Italy
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Yang X, Walstrom A, Tsvetkov N, Pink M, Caulton KG. Influence of Chelate Substituents on the Structure and Spin State of Unsaturated [N(SiMe2CH2PtBu2)2]Ru−X. Inorg Chem 2007; 46:4612-6. [PMID: 17461579 DOI: 10.1021/ic070283x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Density functional theory calculations on the conformational preferences in the two fused five-membered rings of anionic N(SiR2CH2PR'2)2 chelated to RuX+ are compared to several experimental structures (X=halide). The calculations consider the structures of both singlet and triplet states and reveal that both the four tBu groups and the crowded juncture (N(SiMe2)2) of the two rings must be included computationally to understand the observed structures. Computational experiments with different substituents R and R' show the reality of N-->Ru pi donation. The cases where X=H and CH3 are also studied.
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Affiliation(s)
- Xiaofan Yang
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
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