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Ludwig S, Hamann FM, Helmdach K, Villinger A, Seidel WW. Tuning the potential of redox-active diphosphine ligands based on the alkyne complexes [Tp*W(CO)L{η 2-C 2(PPh 2) 2}]. Dalton Trans 2023; 52:326-337. [PMID: 36504075 DOI: 10.1039/d2dt02794a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Eleven complexes with the general formula [Tp*W(CO)L{η2-C2(PPh2)2}]n+ {Tp* = hydridotris(3,4,5-trimethylpyrazolyl)-borate, L = F-, Cl-, Br-, I-, MeS-, PhS-, pyCH2S-, CN- and TfO-; n = 0 and L = CH3CN and pyridine; n = 1} have been synthesized and fully characterized. Depending on L, the oxidation process from W(II) to W(III) is detected between -0.28 and +0.55 V vs. Fc/Fc+ and the spectroscopic properties (X-ray, IR, and NMR) are influenced according to the electron-rich or electron-poor character of the central metal. The basicity of the alkyne complex-based phosphine groups was estimated by the 31P/77Se coupling method of the corresponding diselenides. Selected examples of the dppa-complex ligands were converted into the corresponding κ2-PdCl2 chelate complexes and employed in a Sonogashira reaction in order to estimate the effect of L on the catalytic behaviour of the dinuclear complexes. While the spectroscopic properties show a good correlation with the redox potential in a mostly linear fashion, catalytic activity is influenced only slightly. The effect of PdCl2 coordination on the alkyne complex is evident from the W(II)/W(III) redox potentials measured by cyclic voltammetry supported by a change of the CO stretching frequency in IR. A comparison of the molecular structures of the alkyne complexes with terminal phosphine groups and the PdCl2 chelate complexes all determined by XRD shows the essential flexibility of the bend-back angles in the alkyne complex moiety.
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Affiliation(s)
- Stephan Ludwig
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.
| | - Friederike M Hamann
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany. .,Leibniz Institut für Katalyse e.V., Albert-Einstein-Straße 29a, 18059 Rostock, Germany
| | - Kai Helmdach
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.
| | - Alexander Villinger
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany.
| | - Wolfram W Seidel
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany. .,Leibniz Institut für Katalyse e.V., Albert-Einstein-Straße 29a, 18059 Rostock, Germany
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Hüttenschmidt M, Lange H, Cordero MAA, Villinger A, Lochbrunner S, Seidel WW. Development and application of redox-active cyclometallating ligands based on W(II) alkyne complexes. Dalton Trans 2022; 51:852-856. [PMID: 35006216 DOI: 10.1039/d1dt02393d] [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 assembly of dinuclear complexes with the ultimate smallest ditopic ligands based on side-on complexes of methyl substituted alkynes is presented. In fact, the coordination of Ru(II) and Ir(III) by a W alkyne complex based cyclometallating metalla-ligand causes close intermetallic electronic cooperation, which substantially changes the electrochemical and photophysical properties of the single isolated moieties.
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Affiliation(s)
| | - Helge Lange
- Institut für Chemie, Universität Rostock, 18055 Rostock, Germany.
| | | | | | - Stefan Lochbrunner
- Institute for Physics and Department of Life, Light and Matter, Universität Rostock, 18051 Rostock, Germany
| | - Wolfram W Seidel
- Institut für Chemie, Universität Rostock, 18055 Rostock, Germany. .,Leibniz-Institut für Katalyse e.V., 18059 Rostock, Germany
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Timmermann C, Thiem P, Wanitschke D, Hüttenschmidt M, Romischke J, Villinger A, Seidel WW. Migratory insertion of isocyanide into a ketenyl-tungsten bond as key step in cyclization reactions. Chem Sci 2021; 13:123-132. [PMID: 35059160 PMCID: PMC8694283 DOI: 10.1039/d1sc06149f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 11/21/2021] [Indexed: 12/28/2022] Open
Abstract
Treatment of the side-on tungsten alkyne complex of ethinylethyl ether [Tp*W(CO)2(η2-C,C'-HCCOCH2CH3)]+ {Tp* = hydridotris(3,4,5-trimethylpyrazolyl)borate} (2a) with n-Bu4NI afforded the end-on ketenyl complex [Tp*W(CO)2(κ1-HCCO)] (4a). This formal 16 ve complex bearing the prototype of a ketenyl ligand is surprisingly stable and converts only under activation by UV light or heat to form a dinuclear complex [Tp*2W2(CO)4(μ-CCH2)] (6). The ketenyl ligand in complex 4a underwent a metal template controlled cyclization reaction upon addition of isocyanides. The oxametallacycles [Tp*W(CO)2{κ2-C,O-C(NHXy)C(H)C(Nu)O}] {Nu = OMe (7), OEt (8), N(i-Pr)2 (9), OH (10), O1/2 (11)} were formed by coordination of Xy-NC (Xy = 2,6-dimethylphenyl) at 4a and subsequent migratory insertion (MI) into the W-ketenyl bond. The resulting intermediate is susceptible to addition reactions with protic nucleophiles. Compounds 2a-PF6, 4a/b, and 7-11 were fully characterized including XRD analysis. The cyclization mechanism has been confirmed both experimentally and by DFT calculations. In cyclic voltammetry, complexes 7-9 are characterized by a reversible W(ii)/W(iii) redox process. The dinuclear complex 11 however shows two separated redox events. Based on cyclic voltammetry measurements with different conducting electrolytes and IR spectroelectrochemical (SEC) measurements the W(ii)/W(iii) mixed valent complex 11+ is assigned to class II in terms of the Robin-Day classification.
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Affiliation(s)
- Christopher Timmermann
- Institut für Chemie, Universität Rostock Albert-Einstein-Straße 3a D-18059 Rostock Germany
| | - Paula Thiem
- Institut für Chemie, Universität Rostock Albert-Einstein-Straße 3a D-18059 Rostock Germany
| | - Dominik Wanitschke
- Institut für Chemie, Universität Rostock Albert-Einstein-Straße 3a D-18059 Rostock Germany
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Straße 29a D-18059 Rostock Germany
| | - Mareike Hüttenschmidt
- Institut für Chemie, Universität Rostock Albert-Einstein-Straße 3a D-18059 Rostock Germany
| | - Johanna Romischke
- Institut für Chemie, Universität Rostock Albert-Einstein-Straße 3a D-18059 Rostock Germany
| | - Alexander Villinger
- Institut für Chemie, Universität Rostock Albert-Einstein-Straße 3a D-18059 Rostock Germany
| | - Wolfram W Seidel
- Institut für Chemie, Universität Rostock Albert-Einstein-Straße 3a D-18059 Rostock Germany
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Straße 29a D-18059 Rostock Germany
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Lange H, Schröder H, Oberem E, Villinger A, Rabeah J, Ludwig R, Neymeyr K, Seidel WW. Facile Synthesis of a Stable Side-on Phosphinyne Complex by Redox Driven Intramolecular Cyclisation. Chemistry 2020; 26:11492-11502. [PMID: 32181544 PMCID: PMC7540294 DOI: 10.1002/chem.201905750] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/08/2020] [Indexed: 11/23/2022]
Abstract
Alkyne complexes with vicinal substitution by a Lewis acid and a Lewis base at the coordinated alkyne are prospective frustrated Lewis pairs exhibiting a particular mutual distance and, hence, a specific activation potential. In this contribution, investigations on the generation of a WII alkyne complex bearing a phosphine as Lewis base and a carbenium group as Lewis acid are presented. Independently on potential substrates added, an intramolecular cyclisation product was always isolated. A subsequent deprotonation step led to an unprecedented side-on λ5 -phosphinyne complex, which is interpreted as highly zwitterionic according to visible absorption spectroscopy supported by TD-DFT. Low-temperature 31 P NMR and EPR spectroscopic measurements combined with time-dependent IR-spectroscopic monitoring provided insights in the mechanism of the cyclisation reaction. Decomposition of the multicomponent IR spectra by multivariate curve resolution and a kinetic hard-modelling approach allowed the derivation of kinetic parameters. Assignment of the individual IR spectra to potential intermediates was provided by DFT calculations.
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Affiliation(s)
- Helge Lange
- Institut für ChemieUniversität RostockAlbert-Einstein-Str. 3a18059RostockGermany
| | - Henning Schröder
- Institut für MathematikUniversität RostockUlmenstraße 6918057RostockGermany
| | - Elisabeth Oberem
- Institut für ChemieUniversität RostockAlbert-Einstein-Str. 3a18059RostockGermany
| | - Alexander Villinger
- Institut für ChemieUniversität RostockAlbert-Einstein-Str. 3a18059RostockGermany
| | - Jabor Rabeah
- Leibniz-Institut für Katalyse e.V.Albert-Einstein-Straße 29a18059RostockGermany
| | - Ralf Ludwig
- Institut für ChemieUniversität RostockAlbert-Einstein-Str. 3a18059RostockGermany
- Leibniz-Institut für Katalyse e.V.Albert-Einstein-Straße 29a18059RostockGermany
| | - Klaus Neymeyr
- Institut für MathematikUniversität RostockUlmenstraße 6918057RostockGermany
- Leibniz-Institut für Katalyse e.V.Albert-Einstein-Straße 29a18059RostockGermany
| | - Wolfram W. Seidel
- Institut für ChemieUniversität RostockAlbert-Einstein-Str. 3a18059RostockGermany
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Rüger J, Timmermann C, Villinger A, Seidel WW. Pathways to Polynuclear Complexes with α-S,N-Substituted Alkynes as Bridging Ligands. Inorg Chem 2019; 58:9270-9279. [DOI: 10.1021/acs.inorgchem.9b00976] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Julia Rüger
- Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Christopher Timmermann
- Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Alexander Villinger
- Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Wolfram W. Seidel
- Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
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Helmdach K, Ludwig S, Villinger A, Hollmann D, Kösters J, Seidel WW. Synthesis and activation potential of an open shell diphosphine. Chem Commun (Camb) 2018; 53:5894-5897. [PMID: 28509932 DOI: 10.1039/c7cc02114c] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A paramagnetic WIII alkyne complex bearing free terminal diphenylphosphino groups at the side-on coordinated alkyne was synthesized using a stepwise template strategy. This moderately stable metal supported open shell diphosphine shows an unprecedented spontaneous splitting of nitric oxide providing a WII-η2-C2{P(NH2)Ph2}{P(O)Ph2}+ complex featuring an amino phosphonium and a phosphine oxide substituent.
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Affiliation(s)
- Kai Helmdach
- Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany.
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Helmdach K, Villinger A, Seidel WW. The Influence of Stepwise P-Oxidation on the Coordination and Redox Behavior of W–Bisphosalkyne Complex Ligands. Organometallics 2017. [DOI: 10.1021/acs.organomet.7b00747] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kai Helmdach
- Institut für
Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany
| | - Alexander Villinger
- Institut für
Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany
| | - Wolfram W. Seidel
- Institut für
Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany
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