1
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Greño M, Pérez-Redondo A, Torrijos J, Varela-Izquierdo V, Yélamos C. Half-Sandwich Zirconium and Hafnium Amidoborane Complexes: Precursors of Hydride Derivatives. Inorg Chem 2024; 63:6576-6588. [PMID: 38567753 PMCID: PMC11022180 DOI: 10.1021/acs.inorgchem.3c02826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 03/08/2024] [Accepted: 03/13/2024] [Indexed: 04/16/2024]
Abstract
Half-sandwich zirconium(IV) and hafnium(IV) complexes with amidoborane and hydride ligands have been isolated in the stoichiometric reactions of mono(pentamethylcyclopentadienyl)metal alkyl and amido derivatives with the amine-boranes NHR2BH3 (R2 = H2, Me2, HtBu). Treatment of the tris(trimethylsilylmethyl) complexes [M(η5-C5Me5)(CH2SiMe3)3] with NH3BH3 (3 equiv) gives the seven-coordinate species [M(η5-C5Me5)(NH2BH3)3] (M = Zr (1), Hf (2)) with three κ2N,H-NH2BH3 ligands. The tris(neophyl) [M(η5-C5Me5)(CH2CMe2Ph)3] or tris(dimethylamido) [M(η5-C5Me5)(NMe2)3] derivatives react with NHMe2BH3 (≥3 equiv) to afford bis(dimethylamidoborane) hydride complexes [M(η5-C5Me5)H(NMe2BH3)2] (M = Zr (3), Hf (4)) via thermally unstable [M(η5-C5Me5)(NMe2BH3)3] species. The reaction of [M(η5-C5Me5)(NMe2)3] and NH2tBuBH3 (≥4 equiv) affords analogous mixed amidoborane hydride derivatives [M(η5-C5Me5)H(NHtBuBH3)(NMe2BH3)] (M = Zr (5), Hf (6)) with κ2N,H-NHtBuBH3 and κ3N,H,H-NMe2BH3 ligands. The addition of NHR2BH3 (≥1 equiv) on the mono(dimethylamido) complexes [M(η5-C5Me5)Cl2(NMe2)] in hexane leads to the precipitation of the ionic compounds [(NHR2)2BH2][{M(η5-C5Me5)Cl2}2(μ-H)3] (R2 = Me2, M = Zr (7), Hf (8); R2 = HtBu, M = Zr (9), Hf (10)). Molecular hydride species [Cl2(η5-C5Me5)M(μ-Cl)(μ-H)2M(η5-C5Me5)Cl(NH2tBu)] (M = Zr (11), Hf (12)) could be isolated from mixtures of complexes [M(η5-C5Me5)Cl2(NMe2)] and lower ratios of NH2tBuBH3. The zirconium complex 11 decomposes in solution to give the mononuclear tert-butylamido derivative [Zr(η5-C5Me5)Cl2(NHtBu)] (13) along with other byproducts.
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Affiliation(s)
- Maider Greño
- Departamento de Química
Orgánica y Química Inorgánica, Instituto de Investigación
Química “Andrés M. del Río” (IQAR), Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain
| | - Adrián Pérez-Redondo
- Departamento de Química
Orgánica y Química Inorgánica, Instituto de Investigación
Química “Andrés M. del Río” (IQAR), Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain
| | - José Torrijos
- Departamento de Química
Orgánica y Química Inorgánica, Instituto de Investigación
Química “Andrés M. del Río” (IQAR), Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain
| | - Víctor Varela-Izquierdo
- Departamento de Química
Orgánica y Química Inorgánica, Instituto de Investigación
Química “Andrés M. del Río” (IQAR), Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain
| | - Carlos Yélamos
- Departamento de Química
Orgánica y Química Inorgánica, Instituto de Investigación
Química “Andrés M. del Río” (IQAR), Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain
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2
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Gulyaeva ES, Osipova ES, Kovalenko SA, Filippov OA, Belkova NV, Vendier L, Canac Y, Shubina ES, Valyaev DA. Two active species from a single metal halide precursor: a case study of highly productive Mn-catalyzed dehydrogenation of amine-boranes via intermolecular bimetallic cooperation. Chem Sci 2024; 15:1409-1417. [PMID: 38274083 PMCID: PMC10806649 DOI: 10.1039/d3sc05356c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/06/2023] [Indexed: 01/27/2024] Open
Abstract
Metal-metal cooperation for inert bond activation is a ubiquitous concept in coordination chemistry and catalysis. While the great majority of such transformations proceed via intramolecular mode in binuclear complexes, to date only a few examples of intermolecular small molecule activation using usually bimetallic frustrated Lewis pairs (Mδ+⋯M'δ-) have been reported. We introduce herein an alternative approach for the intermolecular bimetallic cooperativity observed in the catalytic dehydrogenation of amine-boranes, in which the concomitant activation of N-H and B-H bonds of the substrate via the synergetic action of Lewis acidic (M+) and basic hydride (M-H) metal species derived from the same mononuclear complex (M-Br). It was also demonstrated that this system generated in situ from the air-stable Mn(i) complex fac-[(CO)3(bis(NHC))MnBr] and NaBPh4 shows high activity for H2 production from several substrates (Me2NHBH3, tBuNH2BH3, MeNH2BH3, NH3BH3) at low catalyst loading (0.1% to 50 ppm), providing outstanding efficiency for Me2NHBH3 (TON up to 18 200) that is largely superior to all known 3d-, s-, p-, f-block metal derivatives and frustrated Lewis pairs (FLPs). These results represent a step forward towards more extensive use of intermolecular bimetallic cooperation concepts in modern homogeneous catalysis.
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Affiliation(s)
- Ekaterina S Gulyaeva
- LCC-CNRS, Université de Toulouse, CNRS, UPS 205 Route de Narbonne 31077 Toulouse Cedex 4 France
- A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS), Russian Academy of Sciences 28/1 Vavilov Str., GSP-1, B-334 Moscow 119334 Russia
| | - Elena S Osipova
- A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS), Russian Academy of Sciences 28/1 Vavilov Str., GSP-1, B-334 Moscow 119334 Russia
| | - Sergey A Kovalenko
- A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS), Russian Academy of Sciences 28/1 Vavilov Str., GSP-1, B-334 Moscow 119334 Russia
| | - Oleg A Filippov
- A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS), Russian Academy of Sciences 28/1 Vavilov Str., GSP-1, B-334 Moscow 119334 Russia
| | - Natalia V Belkova
- A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS), Russian Academy of Sciences 28/1 Vavilov Str., GSP-1, B-334 Moscow 119334 Russia
| | - Laure Vendier
- LCC-CNRS, Université de Toulouse, CNRS, UPS 205 Route de Narbonne 31077 Toulouse Cedex 4 France
| | - Yves Canac
- LCC-CNRS, Université de Toulouse, CNRS, UPS 205 Route de Narbonne 31077 Toulouse Cedex 4 France
| | - Elena S Shubina
- A. N. Nesmeyanov Institute of Organoelement Compounds (INEOS), Russian Academy of Sciences 28/1 Vavilov Str., GSP-1, B-334 Moscow 119334 Russia
| | - Dmitry A Valyaev
- LCC-CNRS, Université de Toulouse, CNRS, UPS 205 Route de Narbonne 31077 Toulouse Cedex 4 France
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3
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Peng C, Liu W, Wang Y. Mechanistic insights into H 3B·NMeH 2 dehydrogenation by Co-based complexes: a DFT perspective. NEW J CHEM 2023. [DOI: 10.1039/d2nj06155d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
Mechanistic insights into Co-catalyzed H3B·NMeH2 dehydrogenation and polyaminoborane formation are carefully investigated using density functional theory.
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Affiliation(s)
- Cheng Peng
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
| | - Wei Liu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
| | - Yong Wang
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
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4
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Nuñez Bahena E, Schafer LL. From Stoichiometric to Catalytic E–H Functionalization by Non-Metallocene Zirconium Complexes─Recent Advances and Mechanistic Insights. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Erick Nuñez Bahena
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Laurel L. Schafer
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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5
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Brodie CN, Sotorrios L, Boyd TM, Macgregor SA, Weller AS. Dehydropolymerization of H 3B·NMeH 2 Mediated by Cationic Iridium(III) Precatalysts Bearing κ 3- iPr-PN RP Pincer Ligands ( R = H, Me): An Unexpected Inner-Sphere Mechanism. ACS Catal 2022; 12:13050-13064. [PMID: 36313521 PMCID: PMC9594342 DOI: 10.1021/acscatal.2c03778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/27/2022] [Indexed: 11/30/2022]
Abstract
![]()
The dehydropolymerization of H3B·NMeH2 to form N-methylpolyaminoborane using neutral
and
cationic catalysts based on the {Ir(iPr-PNHP)} fragment [iPr-PNHP = κ3-(CH2CH2PiPr2)2NH] is reported. Neutral
Ir(iPr-PNHP)H3 or
Ir(iPr-PNHP)H2Cl
precatalysts show no, or poor and unselective, activity respectively
at 298 K in 1,2-F2C6H4 solution.
In contrast, addition of [NMeH3][BArF4] (ArF = 3,5-(CF3)2C6H3) to Ir(iPr-PNHP)H3 immediately starts catalysis, suggesting that a cationic
catalytic manifold operates. Consistent with this, independently synthesized
cationic precatalysts are active (tested between 0.5 and 2.0 mol %
loading) producing poly(N-methylaminoborane) with Mn ∼ 40,000 g/mol, Đ ∼1.5, i.e., dihydrogen/dihydride, [Ir(iPr-PNHP)(H)2(H2)][BArF4]; σ-amine-borane [Ir(iPr-PNHP)(H)2(H3B·NMe3)][BArF4]; and [Ir(iPr-PNHP)(H)2(NMeH2)][BArF4]. Density functional theory (DFT) calculations
probe hydride exchange processes in two of these complexes and also
show that the barrier to amine-borane dehydrogenation is lower (22.5
kcal/mol) for the cationic system compared with the neutral system
(24.3 kcal/mol). The calculations show that the dehydrogenation proceeds
via an inner-sphere process without metal–ligand cooperativity,
and this is supported experimentally by N–Me substituted [Ir(iPr-PNMeP)(H)2(H3B·NMe3)][BArF4] being
an active catalyst. Key to the lower barrier calculated for the cationic
system is the outer-sphere coordination of an additional H3B·NMeH2 with the N–H group of the ligand.
Experimentally, kinetic studies indicate a complex reaction manifold
that shows pronounced deceleratory temporal profiles. As supported
by speciation and DFT studies, a key observation is that deprotonation
of [Ir(iPr-NHP)(H)2(H2)][BArF4], formed upon amine-borane
dehydrogenation, by the slow in situ formation of NMeH2 (via B–N bond cleavage), results in the formation of essentially
inactive Ir(iPr-PNHP)H3, with a coproduct of [NMeH3]+/[H2B(NMeH2)2]+. While reprotonation
of Ir(iPr-PNHP)H3 results in a return to the cationic cycle, it is proposed, supported
by doping experiments, that reprotonation is attenuated by entrainment
of the [NMeH3]+/[H2B(NMeH2)2]+/catalyst in insoluble polyaminoborane.
The role of [NMeH3]+/[H2B(NMeH2)]+ as chain control agents is also noted.
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Affiliation(s)
| | - Lia Sotorrios
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Timothy M. Boyd
- Department of Chemistry, University of York, York YO10 5DD, U.K
- Chemistry Research Laboratories, University of Oxford, Oxford OX1 3TA, U.K
| | - Stuart A. Macgregor
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
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6
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Maier M, Klopf J, Glasmacher C, Fantuzzi F, Bachmann J, Ayhan O, Koner A, Engels B, Helten H. Electrophilic activation of difunctional aminoboranes: B-N coupling versus intramolecular Cl/Me exchange. Chem Commun (Camb) 2022; 58:4464-4467. [PMID: 35293910 DOI: 10.1039/d2cc00976e] [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
Treatment of an N-silyl-B-chloro-aminoborane with substoichio-metric quantities of Me3SiOTf afforded B-N coupling, whereas activation with 5 mol% of Ag[Al{OC(CF3)3}4] led to Cl/Me exchange between the boron and the silicon center. Combined experimental and computational studies of the latter process support a chain reaction that is initiated by nucleation-limited chloride abstraction.
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Affiliation(s)
- Matthias Maier
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Jonas Klopf
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Clemens Glasmacher
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Felipe Fantuzzi
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany. .,Institute for Physical and Theoretical Chemistry Julius-Maximilians-Universität Würzburg, Emil-Fischer-Strasse 42, 97074 Würzburg, Germany.
| | - Jonas Bachmann
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Ozan Ayhan
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Abhishek Koner
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
| | - Bernd Engels
- Institute for Physical and Theoretical Chemistry Julius-Maximilians-Universität Würzburg, Emil-Fischer-Strasse 42, 97074 Würzburg, Germany.
| | - Holger Helten
- Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
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7
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Cabeza JA, García-Álvarez P, Gómez-Gallego M, Sierra MA. Advances in the synthesis and reactivity of group 6 metal allenyls. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2022. [DOI: 10.1016/bs.adomc.2022.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Lindenau K, Spannenberg A, Reiß F, Beweries T. Mono- and dinuclear zirconocene( iv) amide complexes for the catalytic dehydropolymerisation of phenylsilane. RSC Adv 2022; 12:26277-26283. [PMID: 36275119 PMCID: PMC9477068 DOI: 10.1039/d2ra04955d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 09/08/2022] [Indexed: 11/21/2022] Open
Abstract
Mono- and dinuclear zirconocene amide complexes were tested as catalysts for the dehydropolymerisation of phenylsilane. The dinuclear complex is surprisingly stable, producing mixtures of polysilanes and cyclic oligomers.
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Affiliation(s)
- Kevin Lindenau
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Fabian Reiß
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Torsten Beweries
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
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9
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Rosenthal U. Take a "Snapshot" of New Syntheses, Reactions, and Characterizations from Unusual Unsaturated Ring Strained Group 4 Metallacycles. Chemistry 2021; 27:17751-17760. [PMID: 34463390 PMCID: PMC9293241 DOI: 10.1002/chem.202102855] [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: 08/05/2021] [Indexed: 11/24/2022]
Abstract
Recently published syntheses, reactions and characterizations of unusual unsaturated ring strained Group 4 metallocene metallacycles like metalla-cyclocumulenes, -cycloallenes and -cycloalkynes with different ring size are updated for the last three years. There exist for some of these metallacycles, depending on the ring size, 7-, 5- and 4-membered compounds. The new results for these metallacycles are summarized here and considered in addition to the former published results. Additionally, several compounds of this type were now characterized by new reactions. For a better understanding of these compounds, some spectroscopical methods as well as theoretical calculations were published. Despite of these all-C-metallacycles, only in some cases the syntheses and reactions for the corresponding hetero-metallacycles were published too. Examples for these metallaheterocyclic compounds will not be considered in this article. All these unusual ring strained compounds have a great potential for a lot of interesting synthetic applications in the future. Additionally, they are very interesting from the theoretical point of view.
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Affiliation(s)
- Uwe Rosenthal
- Leibniz Institute for CatalysisUniversity of RostockAlbert-Einstein-Str. 29 A18059RostockGermany
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10
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Brodie CN, Boyd TM, Sotorríos L, Ryan DE, Magee E, Huband S, Town JS, Lloyd-Jones GC, Haddleton DM, Macgregor SA, Weller AS. Controlled Synthesis of Well-Defined Polyaminoboranes on Scale Using a Robust and Efficient Catalyst. J Am Chem Soc 2021; 143:21010-21023. [PMID: 34846131 DOI: 10.1021/jacs.1c10888] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The air tolerant precatalyst, [Rh(L)(NBD)]Cl ([1]Cl) [L = κ3-(iPr2PCH2CH2)2NH, NBD = norbornadiene], mediates the selective synthesis of N-methylpolyaminoborane, (H2BNMeH)n, by dehydropolymerization of H3B·NMeH2. Kinetic, speciation, and DFT studies show an induction period in which the active catalyst, Rh(L)H3 (3), forms, which sits as an outer-sphere adduct 3·H3BNMeH2 as the resting state. At the end of catalysis, dormant Rh(L)H2Cl (2) is formed. Reaction of 2 with H3B·NMeH2 returns 3, alongside the proposed formation of boronium [H2B(NMeH2)2]Cl. Aided by isotopic labeling, Eyring analysis, and DFT calculations, a mechanism is proposed in which the cooperative "PNHP" ligand templates dehydrogenation, releasing H2B═NMeH (ΔG‡calc = 19.6 kcal mol-1). H2B═NMeH is proposed to undergo rapid, low barrier, head-to-tail chain propagation for which 3 is the catalyst/initiator. A high molecular weight polymer is formed that is relatively insensitive to catalyst loading (Mn ∼71 000 g mol-1; Đ, of ∼ 1.6). The molecular weight can be controlled using [H2B(NMe2H)2]Cl as a chain transfer agent, Mn = 37 900-78 100 g mol-1. This polymerization is suggested to arise from an ensemble of processes (catalyst speciation, dehydrogenation, propagation, chain transfer) that are geared around the concentration of H3B·NMeH2. TGA and DSC thermal analysis of polymer produced on scale (10 g, 0.01 mol % [1]Cl) show a processing window that allows for melt extrusion of polyaminoborane strands, as well as hot pressing, drop casting, and electrospray deposition. By variation of conditions in the latter, smooth or porous microstructured films or spherical polyaminoboranes beads (∼100 nm) result.
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Affiliation(s)
- Claire N Brodie
- Department of Chemistry, University of York, Heslington, York YO31 1ES, U.K
| | - Timothy M Boyd
- Department of Chemistry, University of York, Heslington, York YO31 1ES, U.K.,Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Lia Sotorríos
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - David E Ryan
- Department of Chemistry, University of York, Heslington, York YO31 1ES, U.K.,Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Eimear Magee
- International Institute for Nanocomposites Manufacturing, WMG, University of Warwick, Coventry CV4 7AL, U.K
| | - Steven Huband
- Department of Physics, University of Warwick, Coventry CV4 7AL, U.K
| | - James S Town
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Guy C Lloyd-Jones
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, Scotland, U.K
| | - David M Haddleton
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Stuart A Macgregor
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Andrew S Weller
- Department of Chemistry, University of York, Heslington, York YO31 1ES, U.K
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11
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Lindenau K, Zander E, Schünemann C, Spannenberg A, Andreev MV, Burlakov VV, Reiß F, Beweries T. Synthesis and Characterization of Dinuclear Allenediide Bridged Hafnocene(IV) Complexes. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kevin Lindenau
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Edgar Zander
- Abteilung für Anorganische Chemie, Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany
| | - Claas Schünemann
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Maxim V. Andreev
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street 28, 119991 Moscow, Russia
| | - Vladimir V. Burlakov
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Street 28, 119991 Moscow, Russia
| | - Fabian Reiß
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Torsten Beweries
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany
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12
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Devillard M, De Albuquerque Pinheiro CA, Caytan E, Roiland C, Dinoi C, Del Rosal I, Alcaraz G. Uncatalyzed Formation of Polyaminoboranes from Diisopropylaminoborane and Primary Amines: a Kinetically Controlled Polymerization Reaction. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202001458] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marc Devillard
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) 35000 Rennes France
| | | | - Elsa Caytan
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) 35000 Rennes France
| | - Claire Roiland
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) 35000 Rennes France
| | - Chiara Dinoi
- LPCNO CNRS & INSA Universitć de Toulouse 135 avenue de Rangueil 31077 Toulouse France
| | - Iker Del Rosal
- LPCNO CNRS & INSA Universitć de Toulouse 135 avenue de Rangueil 31077 Toulouse France
| | - Gilles Alcaraz
- Univ Rennes CNRS ISCR (Institut des Sciences Chimiques de Rennes) 35000 Rennes France
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13
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Lindenau K, Jannsen N, Rippke M, Al Hamwi H, Selle C, Drexler HJ, Spannenberg A, Sawall M, Neymeyr K, Heller D, Reiß F, Beweries T. Mechanistic insights into dehydrocoupling of amine boranes using dinuclear zirconocene complexes. Catal Sci Technol 2021. [DOI: 10.1039/d1cy00531f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Catalytic dehydrocoupling of H3B·NMe2H using Cp2Zr(Cl)(μ-Me3SiC3SiMe3)Zr(Cl)Cp2 (1)/MeLi was studied. Spectroscopic monitoring and stoichiometric experiments show the formation and interconversion of several catalytically active Zr species.
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Affiliation(s)
| | - Nora Jannsen
- Leibniz-Institut für Katalyse e.V
- 18059 Rostock
- Germany
| | - Mirko Rippke
- Leibniz-Institut für Katalyse e.V
- 18059 Rostock
- Germany
| | | | - Carmen Selle
- Leibniz-Institut für Katalyse e.V
- 18059 Rostock
- Germany
| | | | | | - Mathias Sawall
- Institut für Mathematik
- Universität Rostock
- 18055 Rostock
- Germany
| | - Klaus Neymeyr
- Leibniz-Institut für Katalyse e.V
- 18059 Rostock
- Germany
- Institut für Mathematik
- Universität Rostock
| | - Detlef Heller
- Leibniz-Institut für Katalyse e.V
- 18059 Rostock
- Germany
| | - Fabian Reiß
- Leibniz-Institut für Katalyse e.V
- 18059 Rostock
- Germany
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14
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Hasche P, Haak J, Anke F, Kubis C, Baumann W, Drexler HJ, Jiao H, Beweries T. Dehydropolymerisation of methylamine borane using highly active rhodium(iii) bis(thiophosphinite) pincer complexes: catalytic and mechanistic insights. Catal Sci Technol 2021. [DOI: 10.1039/d1cy00124h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The bis(thiophosphinite) pincer complexes [(RPSCSPR)Rh(py)(H)(Cl)] (RPSCSPR = C6H4–2,6-(SPR2)2 with R = iPr, 2a and R = Ph, 2b) are highly active precatalysts for the dehydropolymerisation of methylamine borane.
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Affiliation(s)
- Patrick Hasche
- Leibniz-Institut für Katalyse e.V. (LIKAT)
- 18059 Rostock
- Germany
| | - Julia Haak
- Leibniz-Institut für Katalyse e.V. (LIKAT)
- 18059 Rostock
- Germany
| | - Felix Anke
- Leibniz-Institut für Katalyse e.V. (LIKAT)
- 18059 Rostock
- Germany
| | - Christoph Kubis
- Leibniz-Institut für Katalyse e.V. (LIKAT)
- 18059 Rostock
- Germany
| | | | | | - Haijun Jiao
- Leibniz-Institut für Katalyse e.V. (LIKAT)
- 18059 Rostock
- Germany
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15
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Anke F, Boye S, Spannenberg A, Lederer A, Heller D, Beweries T. Dehydropolymerisation of Methylamine Borane and an N-Substituted Primary Amine Borane Using a PNP Fe Catalyst. Chemistry 2020; 26:7889-7899. [PMID: 32118328 PMCID: PMC7383739 DOI: 10.1002/chem.202000809] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Indexed: 01/30/2023]
Abstract
Dehydropolymerisation of methylamine borane (H3 B⋅NMeH2 ) using the well-known iron amido complex [(PNP)Fe(H)(CO)] (PNP=N(CH2 CH2 PiPr2 )2 ) (1) gives poly(aminoborane)s by a chain-growth mechanism. In toluene, rapid dehydrogenation of H3 B⋅NMeH2 following first-order behaviour as a limiting case of a more general underlying Michaelis-Menten kinetics is observed, forming aminoborane H2 B=NMeH, which selectively couples to give high-molecular-weight poly(aminoborane)s (H2 BNMeH)n and only traces of borazine (HBNMe)3 by depolymerisation after full conversion. Based on a series of comparative experiments using structurally related Fe catalysts and dimethylamine borane (H3 B⋅NMe2 H) polymer formation is proposed to occur by nucleophilic chain growth as reported earlier computationally and experimentally. A silyl functionalised primary borane H3 B⋅N(CH2 SiMe3 )H2 was studied in homo- and co-dehydropolymerisation reactions to give the first examples for Si containing poly(aminoborane)s.
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Affiliation(s)
- Felix Anke
- Leibniz-Institut für Katalyse e.V.Albert-Einstein-Str. 29a18059RostockGermany
| | - Susanne Boye
- Leibniz-Institut für Polymerforschung DresdenHohe Str. 601069DresdenGermany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V.Albert-Einstein-Str. 29a18059RostockGermany
| | - Albena Lederer
- Leibniz-Institut für Polymerforschung DresdenHohe Str. 601069DresdenGermany
- Technische Universität Dresden01062DresdenGermany
| | - Detlef Heller
- Leibniz-Institut für Katalyse e.V.Albert-Einstein-Str. 29a18059RostockGermany
| | - Torsten Beweries
- Leibniz-Institut für Katalyse e.V.Albert-Einstein-Str. 29a18059RostockGermany
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16
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Boyd TM, Andrea KA, Baston K, Johnson A, Ryan DE, Weller AS. A simple cobalt-based catalyst system for the controlled dehydropolymerisation of H3B·NMeH2 on the gram-scale. Chem Commun (Camb) 2020; 56:482-485. [DOI: 10.1039/c9cc08864d] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A simple Co-based catalyst system promotes the efficient and controlled dehydropolymerisation of amine–boranes on scale.
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Affiliation(s)
- Timothy M. Boyd
- Department of Chemistry
- Chemistry Research Laboratories
- University of Oxford
- Oxford
- UK
| | - Kori A. Andrea
- Department of Chemistry
- Chemistry Research Laboratories
- University of Oxford
- Oxford
- UK
| | - Katherine Baston
- Department of Chemistry
- Chemistry Research Laboratories
- University of Oxford
- Oxford
- UK
| | - Alice Johnson
- Department of Chemistry
- Chemistry Research Laboratories
- University of Oxford
- Oxford
- UK
| | - David E. Ryan
- Department of Chemistry
- Chemistry Research Laboratories
- University of Oxford
- Oxford
- UK
| | - Andrew S. Weller
- Department of Chemistry
- Chemistry Research Laboratories
- University of Oxford
- Oxford
- UK
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17
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Rosenthal U. Equilibria and mesomerism/valence tautomerism of group 4 metallocene complexes. Chem Soc Rev 2020; 49:2119-2139. [DOI: 10.1039/c9cs00637k] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Priority of equilibrium: reactivity of unusual group 4 metallocene complexes is best explained by the equilibrium and only additionally by the mesomerism/valence tautomerism. The equilibrium predominates the empirically found experimental results.
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Affiliation(s)
- Uwe Rosenthal
- Leibniz-Institute for Catalysis at the University of Rostock
- 19059 Rostock
- Germany
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18
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Arz MI, Knights AW, Manners I. Synthesis and Post-Polymerization Functionalization of Halogen-Substituted Polyphosphinoboranes to Access Alkyne-Functionalized Derivatives. Macromol Rapid Commun 2019; 41:e1900468. [PMID: 31880037 DOI: 10.1002/marc.201900468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/19/2019] [Indexed: 01/12/2023]
Abstract
Catalytic dehydropolymerization of halogen-functionalized phosphine-boranes (4-X-C6 H4 )PH2 ⋅BH3 (1a: X = Br, 1b: X = I) with [CpFe(CO)2 (OTf)] at 100 °C provides convenient access to halogen-functionalized polyphosphinoboranes [(4-X-C6 H4 )PH-BH2 ]n (2a: X = Br, 2b: X = I). These polymers are useful precursors for post-polymerization functionalization, which is demonstrated by Sonogashira coupling under mild conditions to yield the alkynyl-functionalized polyphosphinoborane [(4-PhCC-C6 H4 )PH-BH2 ]n (3).
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Affiliation(s)
- Marius I Arz
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Alastair W Knights
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Ian Manners
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.,Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada
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19
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LaPierre EA, Patrick BO, Manners I. Trivalent Titanocene Alkyls and Hydrides as Well-Defined, Highly Active, and Broad Scope Precatalysts for Dehydropolymerization of Amine-Boranes. J Am Chem Soc 2019; 141:20009-20015. [DOI: 10.1021/jacs.9b11112] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Etienne A. LaPierre
- Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada
| | - Brian O. Patrick
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Ian Manners
- Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada
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20
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Resendiz-Lara DA, Whittell GR, Leitao EM, Manners I. Catalytic Synthesis, Characterization, and Properties of Polyaminoborane Homopolymers and Random Copolymers. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01139] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
| | - George R. Whittell
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K
| | - Erin M. Leitao
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K
| | - Ian Manners
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K
- Department of Chemistry, University of Victoria, Victoria, BC V8W 3V6, Canada
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21
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Knitsch R, Han D, Anke F, Ibing L, Jiao H, Hansen MR, Beweries T. Fe(II) Hydride Complexes for the Homogeneous Dehydrocoupling of Hydrazine Borane: Catalytic Mechanism via DFT Calculations and Detailed Spectroscopic Characterization. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Robert Knitsch
- Institute for Physical Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
| | - Delong Han
- Leibniz-Institut für Katalyse an der Universität Rostock e.V., Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
| | - Felix Anke
- Leibniz-Institut für Katalyse an der Universität Rostock e.V., Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
| | - Lukas Ibing
- Institute for Physical Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
- MEET Battery Research
Center, Westfälische Wilhelms-Universität Münster, Corrensstr. 46, 48149 Münster, Germany
| | - Haijun Jiao
- Leibniz-Institut für Katalyse an der Universität Rostock e.V., Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
| | - Michael Ryan Hansen
- Institute for Physical Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstr. 28/30, 48149 Münster, Germany
| | - Torsten Beweries
- Leibniz-Institut für Katalyse an der Universität Rostock e.V., Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
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22
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Reiß F, Reiß M, Bresien J, Spannenberg A, Jiao H, Baumann W, Arndt P, Beweries T. 1-Titanacyclobuta-2,3-diene - an elusive four-membered cyclic allene. Chem Sci 2019; 10:5319-5325. [PMID: 31191888 PMCID: PMC6540905 DOI: 10.1039/c9sc01002e] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 04/20/2019] [Indexed: 11/28/2022] Open
Abstract
The synthesis and characterisation of a 1-titanacyclobuta-2,3-diene complex, an organometallic analog of elusive 1,2-cyclobutadiene, is presented.
The synthesis of an unusual 1-metalla-2,3-cyclobutadiene complex [rac-(ebthi)Ti(Me3SiC3SiMe3)] (rac-ebthi = rac-1,2-ethylene-1,1′-bis(η5-tetrahydroindenyl)), a formal metallacyclic analogue of a non-existent four-membered 1,2-cyclobutadiene, is described. By variation of the cyclopentadienyl ligand of the titanocene precursor it was possible to stabilise this highly exotic compound which selectively reacts with ketones and aldehydes to yield enynes by oxygen transfer to titanium. Analysis of the bonding and electronic structure of the metallacycle shows that the complex is best described as an unusual antiferromagnetically coupled biradicaloid system, possessing a formal Ti(iii) centre coordinated with a monoanionic radical ligand.
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Affiliation(s)
- Fabian Reiß
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock , Albert-Einstein-Str. 29a , 18059 Rostock , Germany . ;
| | - Melanie Reiß
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock , Albert-Einstein-Str. 29a , 18059 Rostock , Germany . ;
| | - Jonas Bresien
- Abteilung für Anorganische Chemie , Institut für Chemie , Universität Rostock , Albert-Einstein-Straße 3a , D-18059 Rostock , Germany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock , Albert-Einstein-Str. 29a , 18059 Rostock , Germany . ;
| | - Haijun Jiao
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock , Albert-Einstein-Str. 29a , 18059 Rostock , Germany . ;
| | - Wolfgang Baumann
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock , Albert-Einstein-Str. 29a , 18059 Rostock , Germany . ;
| | - Perdita Arndt
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock , Albert-Einstein-Str. 29a , 18059 Rostock , Germany . ;
| | - Torsten Beweries
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock , Albert-Einstein-Str. 29a , 18059 Rostock , Germany . ;
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23
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Del Horno E, Jover J, Mena M, Pérez-Redondo A, Yélamos C. Ammonia-Borane Derived BN Fragments Trapped on Bi- and Trimetallic Titanium(III) Systems. Chemistry 2019; 25:7096-7100. [PMID: 30866106 DOI: 10.1002/chem.201900083] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Indexed: 11/06/2022]
Abstract
Titanium(III) complexes containing unprecedented (NH2 BH2 NHBH3 )2- and {N(BH3 )3 }3- ligands have been isolated, and their structures elucidated by a combination of experimental and theoretical methods. The treatment of the trimethyl derivative [TiCp*Me3 ] (Cp*=η5 -C5 Me5 ) with NH3 BH3 (3 equiv) at room temperature gives the paramagnetic dinuclear complex [{TiCp*(NH2 BH3 )}2 (μ-NH2 BH2 NHBH3 )], which at 80 °C leads to the trinuclear hydride derivative [{TiCp*(μ-H)}3 {μ3 -N(BH3 )3 }]. The bonding modes of the anionic BN fragments in those complexes, as well as the dimethylaminoborane group trapped on the analogous trinuclear [{TiCp*(μ-H)}3 (μ3 -H)(μ3 -NMe2 BH2 )], have been studied by X-ray crystallography and density functional theory (DFT) calculations.
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Affiliation(s)
- Estefanía Del Horno
- Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, 28805, Alcalá, de Henares-Madrid, Spain
| | - Jesús Jover
- Department de Química Inorgànica i Orgànica, Institut de Química Teòrica i Computacional (IQTC-UB), Universitat de Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Spain
| | - Miguel Mena
- Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, 28805, Alcalá, de Henares-Madrid, Spain
| | - Adrián Pérez-Redondo
- Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, 28805, Alcalá, de Henares-Madrid, Spain
| | - Carlos Yélamos
- Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, 28805, Alcalá, de Henares-Madrid, Spain
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24
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Adams GM, Ryan DE, Beattie NA, McKay AI, Lloyd-Jones GC, Weller AS. Dehydropolymerization of H 3B·NMeH 2 Using a [Rh(DPEphos)] + Catalyst: The Promoting Effect of NMeH 2. ACS Catal 2019; 9:3657-3666. [PMID: 30984472 PMCID: PMC6454579 DOI: 10.1021/acscatal.9b00081] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/02/2019] [Indexed: 01/01/2023]
Abstract
![]()
[Rh(κ2-PP-DPEphos){η2η2-H2B(NMe3)(CH2)2tBu}][BArF4]
acts as an effective precatalyst
for the dehydropolymerization of H3B·NMeH2 to form N-methylpolyaminoborane (H2BNMeH)n. Control of polymer molecular weight is
achieved by variation of precatalyst loading (0.1–1 mol %,
an inverse relationship) and use of the chain-modifying agent H2: with Mn ranging between 5 500
and 34 900 g/mol and Đ between 1.5 and
1.8. H2 evolution studies (1,2-F2C6H4 solvent) reveal an induction period that gets longer
with higher precatalyst loading and complex kinetics with a noninteger
order in [Rh]TOTAL. Speciation studies at 10 mol % indicate
the initial formation of the amino–borane bridged dimer, [Rh2(κ2-PP-DPEphos)2(μ-H)(μ-H2BN=HMe)][BArF4], followed by the crystallographically
characterized amidodiboryl complex [Rh2(cis-κ2-PP-DPEphos)2(σ,μ-(H2B)2NHMe)][BArF4]. Adding
∼2 equiv of NMeH2 in tetrahydrofuran (THF) solution
to the precatalyst removes this induction period, pseudo-first-order
kinetics are observed, a half-order relationship to [Rh]TOTAL is revealed with regard to dehydrogenation, and polymer molecular
weights are increased (e.g., Mn = 40 000
g/mol). Speciation studies suggest that NMeH2 acts to form
the precatalysts [Rh(κ2-DPEphos)(NMeH2)2][BArF4] and [Rh(κ2-DPEphos)(H)2(NMeH2)2][BArF4], which were independently synthesized and shown to
follow very similar dehydrogenation kinetics, and produce polymers
of molecular weight comparable with [Rh(κ2-PP-DPEphos){η2-H2B(NMe3)(CH2)2tBu}][BArF4], which has been doped
with amine. This promoting effect of added amine in situ is shown
to be general in other cationic Rh-based systems, and possible mechanistic
scenarios are discussed.
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Affiliation(s)
- Gemma M. Adams
- Chemistry Research Laboratories, Mansfield Road, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - David E. Ryan
- Chemistry Research Laboratories, Mansfield Road, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Nicholas A. Beattie
- Institute of Chemical Sciences, Heriot Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Alasdair I. McKay
- Chemistry Research Laboratories, Mansfield Road, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Guy C. Lloyd-Jones
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Andrew S. Weller
- Chemistry Research Laboratories, Mansfield Road, University of Oxford, Oxford OX1 3TA, United Kingdom
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25
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Han D, Anke F, Trose M, Beweries T. Recent advances in transition metal catalysed dehydropolymerisation of amine boranes and phosphine boranes. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2018.09.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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26
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Colebatch AL, Weller AS. Amine-Borane Dehydropolymerization: Challenges and Opportunities. Chemistry 2019; 25:1379-1390. [PMID: 30338876 PMCID: PMC6391989 DOI: 10.1002/chem.201804592] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Indexed: 11/23/2022]
Abstract
The dehydropolymerization of amine-boranes, exemplified as H2 RB⋅NR'H2 , to produce polyaminoboranes (HRBNR'H)n that are inorganic analogues of polyolefins with alternating main-chain B-N units, is an area with significant potential, stemming from both fundamental (mechanism, catalyst development, main-group hetero-cross-coupling) and technological (new polymeric materials) opportunities. This Concept article outlines recent advances in the field, covering catalyst development and performance, current mechanistic models, and alternative non-catalytic routes for polymer production. The substrate scope, polymer properties and applications of these exciting materials are also outlined. Challenges and opportunities in the field are suggested, as a way of providing focus for future investigations.
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Affiliation(s)
- Annie L. Colebatch
- Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
- Department of ChemistryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - Andrew S. Weller
- Department of ChemistryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
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