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Pecak J, Talmazan RA, Svatunek D, Kirchner K, Podewitz M. Is Mn(I) More Promising Than Fe(II)-A Comparison of Mn vs Fe Complexes for Olefin Metathesis. Organometallics 2024; 43:457-466. [PMID: 38425381 PMCID: PMC10900517 DOI: 10.1021/acs.organomet.3c00398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/05/2024] [Accepted: 01/11/2024] [Indexed: 03/02/2024]
Abstract
Olefin metathesis is one of the most significant transformations in organic chemistry and is an excellent example for efficient homogeneous catalysis. Although most currently used catalysts are primarily based on 4d and 5d metals, cycloaddition and cycloreversion reactions can also be attributed to first-row transition metals, such as Fe. Surprisingly, the potential of Mn(I)-based catalysts for olefin metathesis has been unexplored despite their prominence in homogeneous catalysis and their diagonal relationship to Ru(II). In the present study, we have investigated the prospective capabilities of Mn complexes for cycloaddition and reversion reactions using density functional theory. Therefore, we have initially compared the literature known iron model systems and their isoelectronic Mn counterparts regarding their reactivity and electronic structure. Next, we constructed potential Mn complexes derived from synthetically accessible species, including carbonyl ligands and obeying octahedral geometry. Based on thermodynamic parameters and the calculation of electronic descriptors, we were able to validate the isodiagonal relationship. Our study serves as guidance for the experimental chemist.
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Affiliation(s)
- Jan Pecak
- Institute
of Materials Chemistry, TU Wien, Getreidemarkt 9, Vienna 1060, Austria
| | - Radu A. Talmazan
- Institute
of Materials Chemistry, TU Wien, Getreidemarkt 9, Vienna 1060, Austria
| | - Dennis Svatunek
- Institute
of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9, Vienna 1060, Austria
| | - Karl Kirchner
- Institute
of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9, Vienna 1060, Austria
| | - Maren Podewitz
- Institute
of Materials Chemistry, TU Wien, Getreidemarkt 9, Vienna 1060, Austria
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Schratzberger H, Liebminger LA, Stöger B, Veiros LF, Kirchner K. Base metal complexes featuring a new pyrazole-derived PCP pincer ligand. Dalton Trans 2023; 52:12410-12422. [PMID: 37594380 DOI: 10.1039/d3dt02111d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
A new pyrazole-derived PCP pincer ligand featuring a 1-methylpyrazole backbone tethered to two di(isopropyl)phosphine moieties via phenylene spacers (P(CH)P-iPr) was prepared. When reacting the ligand with group six carbonyl complexes [M(CO)6] (M = Cr, Mo, W) at 130 °C, complexes of the type [M(κ2PN-PCP-iPr)(CO)4] were obtained featuring a κ2P,N-bound ligand with a pendant phosphine arm. Upon an increase of the reaction temperature to 150 °C, in the case of molybdenum, the formation of the complex [Mo(κ3PCP-PCP-iPr)(CO)3] was observed featuring a weak Mo-C bond. DFT calculations reveal that there is no agostic η2-C-H interaction. Treatment of [Mn2(CO)10], [Fe2(CO)9], [Co2(CO)8] and [Ni(COD)2] afforded complexes [Mn(κ3PCP-PCP-iPr)(CO)3], [Fe(κ3PCP-PCP-iPr)(H)(CO)2], [Co(κ3PCP-PCP-iPr)(CO)2] and [Ni(κ3PCP-PCP-iPr)(H)], respectively, where the PCP ligand is coordinated in the typical meridional κ3-fashion. Postfunctionalization of the anionic PCP pincer ligand was possible via N-methylation of the second nitrogen atom of the pyrazole unit with the oxonium salt [Me3O]BF4. Treatment of [Mn(κ3PCP-PCP-iPr)(CO)3] and [Fe(κ3PCP-PCP-iPr)(H)(CO)2] with [Me3O]BF4 resulted in the formation of the cationic complexes [Mn(κ3PCP-PCPMe-iPr)(CO)3]+ and [Fe(κ3PCP-PCPMe-iPr)(Cl)(CO)2]+. In the case of the latter, the chloride ligand seems to originate from the solvent CH2Cl2 undergoing a hydride chloride exchange. All complexes were characterized by means of 1H, 13C{1H}, and 31P{1H} NMR spectroscopy, IR spectroscopy and HR-MS. In addition, the structures of representative complexes were determined by X-ray crystallography.
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Affiliation(s)
- Heiko Schratzberger
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9, A-1060 Vienna, Austria.
| | - Lorenzo A Liebminger
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9, A-1060 Vienna, Austria.
| | - Berthold Stöger
- X-Ray Center, TU Wien, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Luis F Veiros
- Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049 001 Lisboa, Portugal
| | - Karl Kirchner
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9, A-1060 Vienna, Austria.
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Liang G, Zhang M. Insights into the Fluxional Processes of Monomethylcyclohexenyl Manganese Tricarbonyl. Molecules 2023; 28:molecules28073232. [PMID: 37049994 PMCID: PMC10096699 DOI: 10.3390/molecules28073232] [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: 03/09/2023] [Revised: 04/02/2023] [Accepted: 04/03/2023] [Indexed: 04/14/2023] Open
Abstract
Multiple fluxional processes of 6-monomethylcyclohexenylmanganese tricarbonyl [(6-MeC6H8)Mn(CO)3, complex 1] and 5-monomethylcyclohexenylmanganese tricarbonyl [(5-MeC6H8)Mn(CO)3, complex 2] have been explored using density functional theory (DFT) computations. The contributions of four agostomers-1, 2, 3, and 4-to the (MeC6H8)Mn(CO)3 exchange processes were revealed. The computational results demonstrated that the 1, 2-agostic isomerization only occurred via the η4-diene hydride transition state (TS-1-2, 14.0 kcal/mol), which is consistent with the experimentally proposed high-energy exchange process (16.0 kcal/mol). Excellent agreement is observed (R2 = 0.9862) when comparing the computed and experimentally observed variable temperature 1H NMR chemical shifts. With these results, important insights into the role of agostic interaction in the homogeneous catalysis process could be made, especially with regard to transition metal catalyzed C-H activation.
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Affiliation(s)
- Guangchao Liang
- Academy of Advanced Interdisciplinary Research, Xidian University, Xi'an 710071, China
| | - Min Zhang
- Department of Pharmacy, School of Medicine, Xi'an International University, Xi'an 710077, China
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Eder W, Himmelbauer D, Stöger B, Veiros LF, Pignitter M, Kirchner K. Manganese and iron PCP pincer complexes - the influence of sterics on structure and reactivity. Dalton Trans 2021; 50:13915-13924. [PMID: 34528031 DOI: 10.1039/d1dt02407h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The syntheses of various manganese and iron PCP pincer complexes via a solvothermal oxidative addition methodology is described. Upon reacting [Mn2(CO)10] with the ligands (P(C-Br)PCH2-iPr) (1a) and (P(C-Br)PO-iPr) (1b), Mn(I) PCP pincer complexes [Mn(PCPCH2-iPr)(CO)3] (2a) and [Mn(-PCPO-iPr)(CO)3] (2b) were obtained. Protonation of 2a with HBF4·Et2O led to the formation of [Mn(κ3P,CH,P-P(CH)PCH2-iPr)(CO)3]BF4 (3) featuring an η2-Caryl-H agostic bond. The solvothermal reaction of 1a with [Fe2(CO)9] afforded the Fe(II) PCP pincer complex [Fe(PCPCH2-iPr)(CO)2Br] (4). Treatment of 4 with Li[HBEt3] afforded the Fe(I) complex [Fe(PCPCH2-iPr)(CO)2] (5a). When using the sterically more demanding ligands (P(C-Br)PCH2-tBu) (1c) and (P(C-Br)PO-tBu)(1d) striking differences in reactivity were observed. While neither 1c nor 1d showed any reactivity towards [Mn2(CO)10], the reaction with [Fe2(CO)9] and [Fe(CO)5] led to the formation of the Fe(I) complexes [Fe(PCPCH2-tBu)(CO)2] (5b) and [Fe(PCPO-tBu)(CO)2] (5c). X-ray structures of representative complexes are provided.
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Affiliation(s)
- Wolfgang Eder
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria.
| | - Daniel Himmelbauer
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria.
| | - Berthold Stöger
- X-Ray Center, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Luis F Veiros
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais No. 1, 1049-001 Lisboa, Portugal
| | - Marc Pignitter
- Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Karl Kirchner
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria.
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Pecak J, Eder W, Stöger B, Realista S, Martinho PN, Calhorda MJ, Linert W, Kirchner K. Synthesis, Characterization, and Catalytic Reactivity of {CoNO} 8 PCP Pincer Complexes. Organometallics 2020; 39:2594-2601. [PMID: 32742055 PMCID: PMC7388324 DOI: 10.1021/acs.organomet.0c00167] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Indexed: 11/28/2022]
Abstract
![]()
The reaction of coordinatively
unsaturated Co(II) PCP pincer complexes
with nitric oxide leads to the formation of new, air-stable, diamagnetic mono nitrosyl compounds. The synthesis
and characterization of five- and four-coordinate Co(III) and Co(I)
nitrosyl pincer complexes based on three different ligand scaffolds
is described. Passing NO through a solution of [Co(PCPNMe-iPr)Cl], [Co(PCPO-iPr)Cl] or [Co(PCPCH2-iPr)Br] led to the
formation of the low-spin complex [Co(PCP-iPr)(NO)X]
with a strongly bent NO ligand. Treatment of the latter species with
(X = Cl, Br) AgBF4 led to chloride abstraction and formation
of cationic square-planar Co(I) complexes of the type [Co(PCP-iPr)(NO)]+ featuring a linear NO group. This
reaction could be viewed as a formal two electron reduction of the
metal center by the NO radical from Co(III) to Co(I), if NO is counted
as NO+. Hence, these systems can be described as {CoNO}8 according to the Enemark–Feltham convention. X-ray
structures, spectroscopic and electrochemical data of all nitrosyl
complexes are presented. Preliminary studies show that [Co(PCPNMe-iPr)(NO)]+ catalyzes efficiently
the reductive hydroboration of nitriles with pinacolborane (HBpin)
forming an intermediate {CoNO}8 hydride species.
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Affiliation(s)
- Jan Pecak
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Wolfgang Eder
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Berthold Stöger
- X-Ray Center, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Sara Realista
- Instituto de Tecnologia Química e Biológica António Xavier, ITQB NOVA, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Paulo N Martinho
- BioISI - Biosystems and Integrative Sciences Institute, DQB, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Maria José Calhorda
- BioISI - Biosystems and Integrative Sciences Institute, DQB, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Wolfgang Linert
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
| | - Karl Kirchner
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9, A-1060 Vienna, Austria
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Synthesis and characterization of xylene-based group-six metal PCP pincer complexes. MONATSHEFTE FUR CHEMIE 2019. [DOI: 10.1007/s00706-019-02422-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Himmelbauer D, Mastalir M, Stöger B, Veiros LF, Kirchner K. Synthesis and Reactivity of Group Six Metal PCP Pincer Complexes: Reversible CO Addition Across the Metal–C aryl Bond. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00447] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | - Luis F. Veiros
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais No. 1, 1049-001 Lisboa, Portugal
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Bezdek MJ, Chirik PJ. Proton-Coupled Electron Transfer to a Molybdenum Ethylene Complex Yields a β-Agostic Ethyl: Structure, Dynamics and Mechanism. J Am Chem Soc 2018; 140:13817-13826. [DOI: 10.1021/jacs.8b08460] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Máté J. Bezdek
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Paul J. Chirik
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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Kadassery KJ, MacMillan SN, Lacy DC. Bisphosphine phenol and phenolate complexes of Mn(i): manganese(i) catalyzed Tishchenko reaction. Dalton Trans 2018; 47:12652-12655. [DOI: 10.1039/c8dt02933d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We synthesized new organomanganese complexes using the phenolic “pincer” type ligand H-POP.
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Affiliation(s)
| | | | - David C. Lacy
- Department of Chemistry
- University at Buffalo
- State University of New York
- Buffalo
- USA
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