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Siddique RG, Whittaker JJ, Al-Fayaad HA, McMurtrie JC, Clegg JK. Remote stereocentres do not disrupt the stereochemical coupling in homochiral [M 2L 3] helicates and [M 4L 6] tetrahedra. Dalton Trans 2023; 52:13487-13491. [PMID: 37725064 DOI: 10.1039/d3dt02486e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Despite the use of achiral ligands, the vast majority of metallosupramolecular assemblies containing octahedral tris-bidentate metal centres show strong stereochemical communication between metal centres, generally resulting in homochiral assemblies even though they are statistically disfavoured. Here we show that when resolved stereocentres are attached to the central part of a quaterpyridine ligand, the stereochemical coupling from this centre is insufficient to disrupt the strong stereochemical communication between metal centres in both [M2L3] helicates and [M4L6] tetrahedra.
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Affiliation(s)
- Rashid G Siddique
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld, 4072, Australia.
| | - Jacob J Whittaker
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld, 4072, Australia.
| | - Hydar A Al-Fayaad
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld, 4072, Australia.
| | - John C McMurtrie
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, Queensland 4000, Australia
| | - Jack K Clegg
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld, 4072, Australia.
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Siddique RG, Arachchige KSA, Al-Fayaad HA, McMurtrie JC, Clegg JK. Sterics and metal-ion radius control the self-assembly of [M 2L 3] helicates. Dalton Trans 2022; 51:12704-12708. [PMID: 35943089 DOI: 10.1039/d2dt02241a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The interplay of many factors influences the outcomes of self-assembly reactions. Using an acetylene-appended quaterpyridine ligand we show that both the size of the metal ion and the presence of steric repulsion between the acetylene groups result in the exclusive formation of [M2L3] helicates rather than a helicate/tetrahedron equilibrium.
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Affiliation(s)
- Rashid G Siddique
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld, 4072, Australia.
| | - Kasun S A Arachchige
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld, 4072, Australia.
| | - Hydar A Al-Fayaad
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld, 4072, Australia.
| | - John C McMurtrie
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, Queensland 4000, Australia
| | - Jack K Clegg
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld, 4072, Australia.
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Siddique RG, Arachchige KSA, Al-Fayaad HA, Thoburn JD, McMurtrie JC, Clegg JK. Controlling the Complexity and Interconversion Mechanisms in Self-Assembled [Fe 2 L 3 ] 4+ Helicates and [Fe 4 L 6 ] 8+ Cages. Angew Chem Int Ed Engl 2021; 61:e202115555. [PMID: 34897921 DOI: 10.1002/anie.202115555] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Indexed: 11/06/2022]
Abstract
Self-assembled coordination cages and metal-organic frameworks have relied extensively on symmetric ligands in their formation. Here we have prepared a relatively simple system employing an unsymmetric ligand that results in two distinct self-assembled structures, a [Fe2 L3 ]4+ helicate and a [Fe4 L6 ]8+ cage composed of 10 interconverting diastereomers and their enantiomers. We show that the steric profile of the ligand controls the complexity, thermodynamics and kinetics of interconversion of the system.
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Affiliation(s)
- Rashid G Siddique
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld 4072, Australia.,Department of Chemistry, School of Natural Sciences (SNS), National University of Science and Technology (NUST), H-12, Islamabad, 46000, Pakistan
| | - Kasun S A Arachchige
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld 4072, Australia
| | - Hydar A Al-Fayaad
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld 4072, Australia
| | - John D Thoburn
- Department of Chemistry, Randolph-Macon College, Ashland, VA 23005, USA
| | - John C McMurtrie
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, Queensland 4000, Australia
| | - Jack K Clegg
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Qld 4072, Australia
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4
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Siddique RG, Arachchige KSA, Al-Fayaad HA, Brock AJ, Micallef AS, Luis ET, Thoburn JD, McMurtrie JC, Clegg JK. The kinetics and mechanism of interconversion within a system of [Fe 2L 3] 4+ helicates and [Fe 4L 6] 8+ cages. Chem Commun (Camb) 2021; 57:4918-4921. [PMID: 33870998 DOI: 10.1039/d1cc01583d] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Nature builds simple molecules into highly complex assemblies, which are involved in all fundamental processes of life. Some of the most intriguing biological assemblies are those that can be precisely reconfigured to achieve different functions using the same building blocks. Understanding the reconfiguration of synthetic self-assembled systems will allow us to better understand the complexity of proteins and design useful artificial chemical systems. Here we have prepared a relatively simple system in which two distinct self-assembled structures, a [Fe2L3]4+ helicate and a [Fe4L6]8+ cage that are formed from the same precursors, coexist at equilibrium. We have measured the rates of interconversion of these two species and propose a mechanism for the transformation.
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Affiliation(s)
- Rashid G Siddique
- School of Chemistry and Molecular Biosciences, The University of Queensland St Lucia, Qld, 4072, Australia.
| | - Kasun S A Arachchige
- School of Chemistry and Molecular Biosciences, The University of Queensland St Lucia, Qld, 4072, Australia.
| | - Hydar A Al-Fayaad
- School of Chemistry and Molecular Biosciences, The University of Queensland St Lucia, Qld, 4072, Australia.
| | - Aidan J Brock
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, Queensland 4000, Australia
| | - Aaron S Micallef
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, Queensland 4000, Australia
| | - Ena T Luis
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, Queensland 4000, Australia
| | - John D Thoburn
- Department of Chemistry, Randolph-Macon College, Ashland, VA 23005, USA
| | - John C McMurtrie
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, Queensland 4000, Australia
| | - Jack K Clegg
- School of Chemistry and Molecular Biosciences, The University of Queensland St Lucia, Qld, 4072, Australia.
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Arachchige KSA, Fahrenhorst-Jones T, Burns JM, Al-Fayaad HA, Behera JN, Rao CNR, Clegg JK, Williams CM. 1,4-Diazacubane crystal structure rectified as piperazinium. Chem Commun (Camb) 2019; 55:11751-11753. [PMID: 31513198 DOI: 10.1039/c9cc06272f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
All 21 [n]-azacubanes are proposed by theoreticians to be stable, however, to-date only the synthesis of 1,4-diazacubane has been reported - as a Ni2+ templated Kagome metal organic framework (MOF). Described herein is the structural reassignment of this Kagome MOF on the basis of deducing the precise experimental procedure, and demonstrating that rather than the formation of 1,4-diazacubane, charge is balanced by disordered piperazinium cations across a twelve-fold symmetry site. Furthermore, quantum chemical calculations reveal that 1,4-diazacubane is unlikely to form under the reported conditions due to unfavorable enthalpies for select hypothetical reactions leading to such a product. This significant structure correction upholds the unconquered synthesis status quo of azacubane.
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Affiliation(s)
| | - Tyler Fahrenhorst-Jones
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, 4072, Queensland, Australia.
| | - Jed M Burns
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, 4072, Queensland, Australia.
| | - Hydar A Al-Fayaad
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, 4072, Queensland, Australia.
| | - Jogendra N Behera
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P. O., Bangalore 560064, India and Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India and School of Chemical Sciences, National Institute of Science Education and Research, Bhubaneswar 752 050, India
| | - C N R Rao
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P. O., Bangalore 560064, India and Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Jack K Clegg
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, 4072, Queensland, Australia.
| | - Craig M Williams
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, 4072, Queensland, Australia.
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