1
|
Krückel T, Schauerte S, Ke J, Schlottmann M, Bausch S, Chen X, Räuber C, Almeida Silva ID, Wiegand T, Albrecht M. 7Li NMR Spectroscopy: A Tool for Determining Dimerization Constants and Averaged Dimerization Constants of the Monomer/Dimer Equilibrium of Hierarchical Helicates. Chemistry 2024; 30:e202400387. [PMID: 38451207 DOI: 10.1002/chem.202400387] [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: 01/29/2024] [Revised: 03/07/2024] [Accepted: 03/25/2024] [Indexed: 03/08/2024]
Abstract
7Li nuclear magnetic resonance (NMR) spectroscopy is an ideal tool to study hierarchically assembled helicates of the form Li[Li3L6Ti2]. Internally bound and external lithium ions can be well distinguished by solution- or solid-state NMR spectroscopy and dimerization constants of the monomer/dimer equilibrium can be easily determined in solution. Averaged dimerization constants can be estimated in case of statistical mixtures of helicates formed from mixtures of ligands.
Collapse
Affiliation(s)
- Tobias Krückel
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, D-52074, Aachen, Germany
| | - Steffen Schauerte
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, D-52074, Aachen, Germany
| | - Jinbo Ke
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, D-52074, Aachen, Germany
| | - Marcel Schlottmann
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, D-52074, Aachen, Germany
| | - Sandra Bausch
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, D-52074, Aachen, Germany
| | - Xiaofei Chen
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, D-52074, Aachen, Germany
| | - Christoph Räuber
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, D-52074, Aachen, Germany
| | | | - Thomas Wiegand
- Max-Planck Institut für chemische Energiekonversion, Stiftstr. 34-36, D-45470, Mülheim/Ruhr, Germany
- Institut für Technische und Makromolekulare Chemie, RWTH Aachen University, Worringerweg 2, D-52074, Aachen, Germany
| | - Markus Albrecht
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, D-52074, Aachen, Germany
| |
Collapse
|
2
|
Albrecht M. The Monomer-Dimer Equilibrium of Triscatechol Titanium(IV)-Based Hierarchical Helicates as a Tool for the Development of Molecular Balances and Molecular Switches. Acc Chem Res 2023; 56:3271-3281. [PMID: 37955356 DOI: 10.1021/acs.accounts.3c00525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
ConspectusHierarchical helicates are formed by noncovalent connection of two or more monomeric metal complex units, e.g., by bridging metal cations. A unique kind of hierarchical helicate is obtained from 3-carbonyl substituted catechol ligands with titanium(IV) ions in the presence of lithium cations. This kind of supramolecular complex shows in solution a "monomer-dimer" equilibrium. There are different possibilities (solvent, countercation, substituents at carbonyl unit, etc.) to shift this equilibrium to either the monomer or the dimer side. Thus, the lithium-bridged catecholate-based hierarchical helicates resemble a molecular switch. In this Account, different aspects are discussed of how this unique behavior of the dimeric titanium catecholates can be used for application.Thorough investigation of the energetics of the monomer-dimer equilibrium leads to a deeper understanding of the thermodynamic and kinetic effects of the dimerization (or dissociation) process. In this context, even weak interaction of substituents in the periphery of the complexes can be observed. Hereby on the one hand, solvent effects have an important influence and can be easily evaluated. The thorough understanding of the behavior of the monomer-dimer equilibrium allows one to develop some novel applications. In this respect, the use of the hierarchical helicate-based switch as a platform for reaction control and catalysis is described. Decent enantioselectivities up to ee = 58% can be found in Diels-Alder reactions in the periphery of the dimers, while switching to the monomer as a reaction platform still allows the cycloaddition reaction but turns the selectivity off. Additionally, it is described that catalytically important units can be introduced and hydrogenation reactions as well as Michael-type reactions are catalyzed at the helicates.Covalent connection of two catechol ester units leads to classical helicates. Depending on the alkaline metal cation, those can be switched from a compressed to an expanded form or vice versa. Hereby the monomer-dimer equilibrium is transformed into a structural switch. The switching process can be initiated by removal or addition of lithium cations (e.g., by addition of [2.1.1]cryptand). Alternative switching possibilities are based in the case of glycol bridged helicates on cation translocation isomerism and with thioester derivatives it occurs spontaneously in DMSO. Introduction of chiral tethers results in a three state switch allowing expansion/compression as well as switching of the helicity.
Collapse
Affiliation(s)
- Markus Albrecht
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, D-52074 Aachen, Germany
| |
Collapse
|
3
|
Schlottmann M, Krückel T, Albrecht M. Stereochemical dominance in hierarchically formed helicates. Chem Commun (Camb) 2022; 58:6104-6107. [PMID: 35506399 DOI: 10.1039/d2cc01411d] [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 competition of different chiral ligands in the control of stereochemistry of hierarchically formed helical coordination compounds is investigated. It is found that sterically demanding chiral units can dominate the chiral induction of the helix even if they are present as a minor species. Hereby the relative strength of stereoinduction of different chiral units can be evaluated.
Collapse
Affiliation(s)
- Marcel Schlottmann
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
| | - Tobias Krückel
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
| | - Markus Albrecht
- Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
| |
Collapse
|
4
|
Scarpi-Luttenauer M, Mobian P, Barloy L. Synthesis, structure and functions of discrete titanium-based multinuclear architectures. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214439] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
5
|
Mevissen C, Kwamen ACN, Himmel L, Chen X, Brückner M, Huda S, Göb C, Jenniches J, Oppel I, Ward JS, Rissanen K, Albrecht M. Helicates with Ether‐Substituted Catechol Esters as Ligands. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000843] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Christian Mevissen
- Institut für Organische Chemie RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - A. Carel N. Kwamen
- Institut für Organische Chemie RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Leonard Himmel
- Institut für Organische Chemie RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Xiaofei Chen
- Institut für Organische Chemie RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Matthias Brückner
- Institut für Organische Chemie RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Saskia Huda
- Institut für Organische Chemie RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Christian Göb
- Institut für Anorganische Chemie RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Judith Jenniches
- Institut für Anorganische Chemie RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Iris Oppel
- Institut für Anorganische Chemie RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Jas S. Ward
- Department of Chemistry University of Jyväskylä P.O. Box 35 40014 Jyväskylä Finland
| | - Kari Rissanen
- Department of Chemistry University of Jyväskylä P.O. Box 35 40014 Jyväskylä Finland
| | - Markus Albrecht
- Institut für Organische Chemie RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| |
Collapse
|
6
|
Kwamen ACN, Jenniches J, Oppel IM, Albrecht M. Solvent Dependence of the Monomer-Dimer Equilibrium of Ketone-Substituted Triscatecholate Titanium(IV) Complexes. Chemistry 2020; 26:10550-10554. [PMID: 32222003 PMCID: PMC7496165 DOI: 10.1002/chem.202001053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/26/2020] [Indexed: 11/25/2022]
Abstract
Hierarchical helicates based on ketone-substituted titanium(IV)triscatecholates show different monomer-dimer behavior depending on different solvents. The dimerization constants of a whole series of differently alkyl-substituted complexes is analyzed to show that the solvent has a very strong influence on the dimerization. Hereby, effects like solvophobicity/philicity, sterics, electronics of the substituents and weak side-chain-side-chain interactions seem to act in concert.
Collapse
Affiliation(s)
- A. Carel N. Kwamen
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 1Aachen52074Germany
| | - Judith Jenniches
- Institut für Anorganische ChemieRWTH Aachen UniversityLandoltweg 1Aachen52074Germany
| | - Iris M. Oppel
- Institut für Anorganische ChemieRWTH Aachen UniversityLandoltweg 1Aachen52074Germany
| | - Markus Albrecht
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 1Aachen52074Germany
| |
Collapse
|
7
|
Affiliation(s)
- Markus Albrecht
- Institut für Organische Chemie RWTH Aachen University Landoltweg 1 D‐52074 Aachen Germany
| |
Collapse
|
8
|
Kwamen ACN, de Macedo GS, Wiederhold C, Oppel IM, Albrecht M. Catechol Thioesters: Ligands for Hierarchically Formed Lithium-Bridged Titanium(IV) Helicates and Helicate-Based Switches. Chemistry 2020; 26:3829-3833. [PMID: 31899932 PMCID: PMC7154688 DOI: 10.1002/chem.201905212] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Indexed: 12/22/2022]
Abstract
The thioester moiety is introduced as a lithium binding unit for the hierarchical formation of titanium(IV) catecholate-based lithium-bridged helicates. In solution, the coordination compounds show a monomer-dimer equilibrium which -in comparison to the oxo esters- is significantly shifted towards the monomers. In addition, the influence of the thioester side chain on the dimerization behavior is investigated and an expansible/compressible molecular switch is synthesized. In the latter case expansion and compression are performed reversibly in methanol, whereas in DMSO spontaneous expansion occurs.
Collapse
Affiliation(s)
- A. Carel N. Kwamen
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Gilles S. de Macedo
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Constanze Wiederhold
- Institut für Anorganische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Iris M. Oppel
- Institut für Anorganische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Markus Albrecht
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| |
Collapse
|
9
|
Schlottmann M, Van Craen D, Baums J, Funes-Ardoiz I, Wiederhold C, Oppel IM, Albrecht M. Stability of Hierarchically Formed Titanium(IV) Tris(catecholate ester) Helicates with Cyclohexyl Substituents in DMSO. Inorg Chem 2020; 59:1758-1762. [PMID: 31967799 DOI: 10.1021/acs.inorgchem.9b02988] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A cyclohexyl substituent strongly prefers the chair conformation with large substituents in equatorial positions, while other cycloalkyls are structurally more flexible. In hierarchically formed dimeric titanium(IV) tris(catecholates) equatorial versus axial connection of the cyclohexane to the ester results in either a more compact (axial) or more expanded (equatorial) structure. In DMSO solution the axial position results in a compact structure which minimizes solvophobic effects, leading to higher stability. However, computational investigations indicate that additionally intramolecular London dispersion interactions significantly contribute to the stability of the dimer. Thus, weak side-chain-side-chain interactions are responsible for the high stability of cyclohexyl ester derivatives with axial compared to equatorial ester connection.
Collapse
Affiliation(s)
- Marcel Schlottmann
- Institut für Organische Chemie , RWTH Aachen University , Landoltweg 1 , 52074 Aachen , Germany
| | - David Van Craen
- Institut für Organische Chemie , RWTH Aachen University , Landoltweg 1 , 52074 Aachen , Germany
| | - Julia Baums
- Institut für Organische Chemie , RWTH Aachen University , Landoltweg 1 , 52074 Aachen , Germany
| | - Ignacio Funes-Ardoiz
- Institut für Organische Chemie , RWTH Aachen University , Landoltweg 1 , 52074 Aachen , Germany
| | - Constanze Wiederhold
- Institut für Anorganische Chemie , RWTH Aachen University , Landoltweg 1 , 52074 Aachen , Germany
| | - Iris M Oppel
- Institut für Anorganische Chemie , RWTH Aachen University , Landoltweg 1 , 52074 Aachen , Germany
| | - Markus Albrecht
- Institut für Organische Chemie , RWTH Aachen University , Landoltweg 1 , 52074 Aachen , Germany
| |
Collapse
|
10
|
Kwamen ACN, Schlottmann M, Van Craen D, Isaak E, Baums J, Shen L, Massomi A, Räuber C, Joseph BP, Raabe G, Göb C, Oppel IM, Puttreddy R, Ward JS, Rissanen K, Fröhlich R, Albrecht M. Shedding Light on the Interactions of Hydrocarbon Ester Substituents upon Formation of Dimeric Titanium(IV) Triscatecholates in DMSO Solution. Chemistry 2020; 26:1396-1405. [PMID: 31737953 PMCID: PMC7027801 DOI: 10.1002/chem.201904639] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Indexed: 01/27/2023]
Abstract
The dissociation of hierarchically formed dimeric triple lithium bridged triscatecholate titanium(IV) helicates with hydrocarbyl esters as side groups is systematically investigated in DMSO. Primary alkyl, alkenyl, alkynyl as well as benzyl esters are studied in order to minimize steric effects close to the helicate core. The 1 H NMR dimerization constants for the monomer-dimer equilibrium show some solvent dependent influence of the side chains on the dimer stability. In the dimer, the ability of the hydrocarbyl ester groups to aggregate minimizes their contacts with the solvent molecules. Due to this, most solvophobic alkyl groups show the highest dimerization tendency followed by alkenyls, alkynyls and finally benzyls. Furthermore, trends within the different groups of compounds can be observed. For example, the dimer is destabilized by internal double or triple bonds due to π-π repulsion. A strong indication for solvent supported London dispersion interaction between the ester side groups is found by observation of an even/odd alternation of dimerization constants within the series of n-alkyls, n-Ω-alkenyls or n-Ω-alkynyls. This corresponds to the interaction of the parent hydrocarbons, as documented by an even/odd melting point alternation.
Collapse
Affiliation(s)
- A. Carel N. Kwamen
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Marcel Schlottmann
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - David Van Craen
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Elisabeth Isaak
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Julia Baums
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Li Shen
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Ali Massomi
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Christoph Räuber
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Benjamin P. Joseph
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Gerhard Raabe
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Christian Göb
- Institut für Anorganische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Iris M. Oppel
- Institut für Anorganische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| | - Rakesh Puttreddy
- University of JyväskyläDepartment of ChemistryP.O. Box 35Jyväskylä40014Finland
| | - Jas S. Ward
- University of JyväskyläDepartment of ChemistryP.O. Box 35Jyväskylä40014Finland
| | - Kari Rissanen
- University of JyväskyläDepartment of ChemistryP.O. Box 35Jyväskylä40014Finland
| | - Roland Fröhlich
- Organisch-Chemisches InstitutUniversität MünsterCorrensstrasse 4048149MünsterGermany
| | - Markus Albrecht
- Institut für Organische ChemieRWTH Aachen UniversityLandoltweg 152074AachenGermany
| |
Collapse
|