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Abstract
Dianionic N,N-chelating ligands play a crucial role in coordination chemistry, but reports on related complexes remain limited to certain types of ligands. In here, the reactions of two diprotic ligands, i.e., a biguanide and a carbothiamide, with trimethylaluminium, are reported, which give rise to mono- and dinuclear aluminium(III) complexes. In addition, single deprotonation of the diprotic biguanide using potassium bis(trimethylsilyl)amide gives rise to a one-dimensional coordination polymer. All complexes have been fully characterized, and their solid-state structures were determined by single crystal X-ray diffraction analysis.
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2
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Rinke P, Görls H, Kretschmer R. Calcium and Magnesium Bis(β-diketiminate) Complexes: Impact of the Alkylene Bridge on Schlenk-Type Rearrangements. Inorg Chem 2021; 60:5310-5321. [PMID: 33667337 DOI: 10.1021/acs.inorgchem.1c00301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Dinuclear heteroleptic alkaline-earth-metal complexes are interesting synthetic targets because the close proximity of two metals allows for cooperative effects. However, these complexes are also prone to undergoing Schlenk-type rearrangements, affording less-active homoleptic complexes. Here we present the metalation of bis(β-diketimine) ligands possessing flexible bridging groups, i.e., 1,2-ethylene, 1,3-propylene, and trans-1,2-cyclohexylene, using calcium and magnesium precursors. Four mononuclear homoleptic calcium complexes were obtained, highlighting the pronounced tendency of calcium to undergo Schlenk-like redistributions. In the case of magnesium, however, the bridging group plays a crucial role, yielding seven dinuclear heteroleptic complexes but also one mononuclear and one dinuclear homoleptic complexes. In addition, a trinuclear mixed heteroleptic-homoleptic magnesium complex, which is a rare example of an intermediate of the Schlenk equilibrium, was isolated.
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Affiliation(s)
- Philipp Rinke
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany.,Jena Center for Soft Matter, Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
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3
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Zuo S, Zhang F, Liu J, Zuo A. Synthesis of bis(2-imino-1,3-dimethylbenzimidazoline)s via reactions of a solvothermally prepared benzimidazolium chloride and diamines. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.152920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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4
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Rösch A, Seifert F, Vass V, Görls H, Kretschmer R. Synthesis, structure, and catalytic activity of dinuclear aluminium bis(amidinate) and bis(guanidinate) complexes. NEW J CHEM 2021. [DOI: 10.1039/d0nj05007e] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The ring-opening polymerization grand prix: Bis(amidinate)s outpaced their bis(guanidinate) competitors and won the race, while the drivers’ engines using acidic co-initiators collapsed before take-off.
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Affiliation(s)
- Andreas Rösch
- Institute of Inorganic Chemistry
- University of Regensburg
- 93053 Regensburg
- Germany
| | - Fabian Seifert
- Institute of Inorganic and Analytical Chemistry
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
| | - Valentin Vass
- Institute of Inorganic Chemistry
- University of Regensburg
- 93053 Regensburg
- Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
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5
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Rösch A, Herzog CM, Schreiner SHF, Görls H, Kretschmer R. Ditopic bis( N, N', N'-substituted 1,2-ethanediamine) ligands: synthesis and coordination chemistry. Dalton Trans 2020; 49:13818-13828. [PMID: 33001083 DOI: 10.1039/d0dt03124k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The synthesis of two different types of bis(N,N',N'-substituted 1,2-ethanediamine)s, bridged either through the secondary (type 1) or tertiary (type 2) amine groups is reported. Selected protio-ligands have been applied in subsequent metallation reactions using aluminium, magnesium, tin, and zinc sources allowing to isolate five mononuclear and eight dinuclear complexes. All complexes have been fully characterized and their solid-state structures have been studied by means of single-crystal X-ray diffraction analysis. Nine of the 13 complexes carry reactive alkyl, amide or hydride groups, which indicates their potential as catalysts or supports for (transition) metals.
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Affiliation(s)
- Andreas Rösch
- Institute of Inorganic Chemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Christoph M Herzog
- Institute of Inorganic Chemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Simon H F Schreiner
- Institute of Inorganic Chemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany and Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena Philosophenweg 7, 07743 Jena, Germany.
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6
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Rösch A, Schreiner SHF, Schüler P, Görls H, Kretschmer R. Magnesium bis(amidinate) and bis(guanidinate) complexes: impact of the ligand backbone and bridging groups on the coordination behaviour. Dalton Trans 2020; 49:13072-13082. [PMID: 32926063 DOI: 10.1039/d0dt01923b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A library of ten dinucleating bis(amidine) and bis(guanidine) ligands, in which the bridging groups, terminal rests, and backbone substituents were systematically altered, has been synthesized and subsequently applied in metallation reactions using three different magnesium sources. Eight Mg complexes could be isolated and fully characterized, and in seven cases their solid-state structure could be determined by means of single crystal X-ray diffraction analysis. The results evidence a versatile coordination behaviour, which ranges from the first dinuclear heteroleptic magnesium iodide complex to dinuclear homoleptic complexes. These findings indicate the crucial impact of both the ligand and the magnesium source not only on the accessibility of well-defined dinuclear complexes but also on the aggregation in solution and in the solid state.
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Affiliation(s)
- Andreas Rösch
- Institute of Inorganic Chemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
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7
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Berlinck RGS, Bernardi DI, Fill T, Fernandes AAG, Jurberg ID. The chemistry and biology of guanidine secondary metabolites. Nat Prod Rep 2020; 38:586-667. [PMID: 33021301 DOI: 10.1039/d0np00051e] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Covering: 2017-2019Guanidine natural products isolated from microorganisms, marine invertebrates and terrestrial plants, amphibians and spiders, represented by non-ribosomal peptides, guanidine-bearing polyketides, alkaloids, terpenoids and shikimic acid derived, are the subject of this review. The topics include the discovery of new metabolites, total synthesis of natural guanidine compounds, biological activity and mechanism-of-action, biosynthesis and ecological functions.
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Affiliation(s)
- Roberto G S Berlinck
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil.
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8
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Calderón‐Díaz A, Arras J, Miller ET, Bhuvanesh N, McMillen CD, Stollenz M. Ethylene‐Bridged Tetradentate Bis(amidines): Supramolecular Assemblies through Hydrogen Bonding and Photoluminescence upon Deprotonation. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000207] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Alvaro Calderón‐Díaz
- Department of Chemistry and Biochemistry Kennesaw State University 370 Paulding Avenue NW, MD1203 30144 Kennesaw GA USA
| | - Janet Arras
- Department of Chemistry and Biochemistry Kennesaw State University 370 Paulding Avenue NW, MD1203 30144 Kennesaw GA USA
| | - Ethan T. Miller
- Department of Chemistry and Biochemistry Kennesaw State University 370 Paulding Avenue NW, MD1203 30144 Kennesaw GA USA
| | - Nattamai Bhuvanesh
- Department of Chemistry Texas A&M University 580 Ross Street, P.O. Box 30012 77842‐3012 College Station TX USA
| | - Colin D. McMillen
- Department of Chemistry Clemson University 379 Hunter Laboratories 29634‐0973 Clemson SC USA
| | - Michael Stollenz
- Department of Chemistry and Biochemistry Kennesaw State University 370 Paulding Avenue NW, MD1203 30144 Kennesaw GA USA
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9
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Dehmel M, Vass V, Prock L, Görls H, Kretschmer R. Synthesis and Coordination Chemistry of 3,4-Ethylene-Bridged 1,1,2,5-Tetrasubstituted Biguanides. Inorg Chem 2020; 59:2733-2746. [PMID: 32048512 DOI: 10.1021/acs.inorgchem.9b03093] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of 3,4-ethylene-bridged 1,1,2,5-tetrasubstituted biguanides is reported, which are accessible by three alternative routes. Exemplary molecular structures of the ligand and an observed side product have been elucidated by X-ray diffraction analysis. Mono- and dinuclear complexes of the biguanide in both its neutral and monoanionic forms were obtained, including examples of aluminum, copper, magnesium, potassium, tin, and zinc, indicating a versatile coordination behavior, as evidenced by means of single-crystal X-ray diffraction analysis.
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Affiliation(s)
- Maximilian Dehmel
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Valentin Vass
- University of Regensburg, Institute of Inorganic Chemistry, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Lukas Prock
- University of Regensburg, Institute of Inorganic Chemistry, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany.,Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena Philosophenweg 7, 07743 Jena, Germany
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10
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Kretschmer R. Ligands with Two Monoanionic N,N-Binding Sites: Synthesis and Coordination Chemistry. Chemistry 2020; 26:2099-2119. [PMID: 31755598 PMCID: PMC7064907 DOI: 10.1002/chem.201903442] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/19/2019] [Indexed: 11/07/2022]
Abstract
Polytopic ligands have become ubiquitous in coordination chemistry because they grant access to a variety of mono- and polynuclear complexes of transition metals as well as rare-earth and main-group elements. Nitrogen-based ditopic ligands, in which two monoanionic N,N-binding sites are framed within one molecule, are of particular importance and are therefore the primary focus of this review. In detail, bis(amidine)s, bis(guanidine)s, bis(β-diimine)s, bis(aminotroponimine)s, bis(pyrrolimine)s, and miscellaneous bis(N,N-chelating) ligands are reviewed. In addition to the general synthetic protocols, the application of these ligands is discussed along with their coordination chemistry, the multifarious binding modes, and the ability of these ligands to bridge two (or more) metal(loids).
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Affiliation(s)
- Robert Kretschmer
- Junior Professorship Inorganic Chemistry of Catalysis, Institute of Inorganic and Analytical ChemistryFriedrich Schiller University JenaHumboldtstrasse 807743JenaGermany
- Jena Center for Soft Matter (JCSM)Friedrich Schiller University JenaPhilosophenweg 707743JenaGermany
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11
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Dawood KM. Bis‐thiourea Derivatives and Their Utility in Synthesis of Mono‐heterocyclic, Bis‐heterocyclic, and Fused Heterocyclic Systems. J Heterocycl Chem 2019. [DOI: 10.1002/jhet.3540] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Kamal M. Dawood
- Chemistry Department, Faculty of ScienceCairo University Giza 12613 Egypt
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