1
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Shi Y, Li C, Di J, Xue Y, Jia Y, Duan J, Hu X, Tian Y, Li Y, Sun C, Zhang N, Xiong Y, Jin T, Chen P. Polycationic Open-Shell Cyclophanes: Synthesis of Electron-Rich Chiral Macrocycles, and Redox-Dependent Electronic States. Angew Chem Int Ed Engl 2024; 63:e202402800. [PMID: 38411404 DOI: 10.1002/anie.202402800] [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: 02/07/2024] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 02/28/2024]
Abstract
π-Conjugated chiral nanorings with intriguing electronic structures and chiroptical properties have attracted considerable interests in synthetic chemistry and materials science. We present the design principles to access new chiral macrocycles (1 and 2) that are essentially built on the key components of main-group electron-donating carbazolyl moieties or the π-expanded aza[7]helicenes. Both macrocycles show the unique molecular conformations with a (quasi) figure-of-eight topology as a result of the conjugation patterns of 2,2',7,7'-spirobifluorenyl in 1 and triarylamine-coupled aza[7]helicene-based building blocks in 2. This electronic nature of redox-active, carbazole-rich backbones enabled these macrocycles to be readily oxidized chemically and electrochemically, leading to the sequential production of a series of positively charged polycationic open-shell cyclophanes. Their redox-dependent electronic states of the resulting multispin polyradicals have been characterized by VT-ESR, UV/Vis-NIR absorption and spectroelectrochemical measurements. The singlet (ΔES-T=-1.29 kcal mol-1) and a nearly degenerate singlet-triplet ground state (ΔES-T(calcd)=-0.15 kcal mol-1 and ΔES-T(exp)=0.01 kcal mol-1) were proved for diradical dications 12+2⋅ and 22+2⋅, respectively. Our work provides an experimental proof for the construction of electron-donating new chiral nanorings, and more importantly for highly charged polyradicals with potential applications in chirospintronics and organic conductors.
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Affiliation(s)
- Yafei Shi
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
| | - Chenglong Li
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
| | - Jiaqi Di
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
| | - Yuting Xue
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
| | - Yawei Jia
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
| | - Jiaxian Duan
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
| | - Xiaoyu Hu
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
| | - Yu Tian
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
| | - Yanqiu Li
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
| | - Cuiping Sun
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
| | - Niu Zhang
- Analysis and Testing Centre, Beijing Institute of Technology, 102488, Beijing, China
| | - Yan Xiong
- Analysis and Testing Centre, Beijing Institute of Technology, 102488, Beijing, China
| | - Tianyun Jin
- Center of Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography University of California, San Diego La Jolla, 92093, USA
| | - Pangkuan Chen
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Medical Molecule Science, Pharmaceutical Engineering of the Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 102488, China
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2
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Van Raden JM, Deng JR, Gotfredsen H, Hergenhahn J, Clarke M, Edmondson M, Hart J, O'Shea JN, Duarte F, Saywell A, Anderson HL. Template-Directed Synthesis of Strained meso-meso-Linked Porphyrin Nanorings. Angew Chem Int Ed Engl 2024; 63:e202400103. [PMID: 38230920 DOI: 10.1002/anie.202400103] [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: 01/02/2024] [Revised: 01/17/2024] [Accepted: 01/17/2024] [Indexed: 01/18/2024]
Abstract
Strained macrocycles display interesting properties, such as conformational rigidity, often resulting in enhanced π-conjugation or enhanced affinity for non-covalent guest binding, yet they can be difficult to synthesize. Here we use computational modeling to design a template to direct the formation of an 18-porphyrin nanoring with direct meso-meso bonds between the porphyrin units. Coupling of a linear 18-porphyrin oligomer in the presence of this template gives the target nanoring, together with an unexpected 36-porphyrin ring by-product. Scanning tunneling microscopy (STM) revealed the elliptical conformations and flexibility of these nanorings on a Au(111) surface.
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Affiliation(s)
- Jeff M Van Raden
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA, UK
| | - Jie-Ren Deng
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA, UK
| | - Henrik Gotfredsen
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA, UK
| | - Janko Hergenhahn
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA, UK
| | - Michael Clarke
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Matthew Edmondson
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Jack Hart
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - James N O'Shea
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Fernanda Duarte
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA, UK
| | - Alex Saywell
- School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA, UK
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3
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Zhao H, Huang L, Liu W, Dong Q, Bai Q, Yuan J, Jiang Z, Chen M, Liu D, Wang J, Li Y, Wang P. Segmented Template-Directed Self-Assembly of Giant Truncated Triangular Supramolecules. Inorg Chem 2024; 63:4152-4159. [PMID: 38372260 DOI: 10.1021/acs.inorgchem.3c03899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
The template-directed strategy has been extensively employed for the construction of supramolecular architectures. However, with the increase in the size and complexity of these structures, the synthesis difficulty of the templates escalates exponentially, thereby impeding the widespread application of this strategy. In this study, two truncated triangles T1 and T2 were successfully self-assembled through a novel segmented template strategy by segmenting the core triangular template into portions. Two metallo-organic ligands L2 and L3 were designed and synthesized by dividing the central stable triangle into three separate parts and incorporating them into the precursor ligands, which served as templates to guide the self-assembly process with ligands L1 and L4, respectively. The assembled structures were unambiguously characterized by multidimensional and multinuclear NMR (1H, COSY, NOESY), multidimensional mass spectrometry analysis (ESI-MS and TWIM-MS), and transmission electron microscopy (TEM). Moreover, we observed the formation of fiberlike nanotubes from single-molecule triangles by hierarchical self-assembly.
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Affiliation(s)
- He Zhao
- Department of Organic and Polymer Chemistry, Hunan Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China
| | - Linlin Huang
- Department of Organic and Polymer Chemistry, Hunan Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China
| | - Wenping Liu
- Department of Organic and Polymer Chemistry, Hunan Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China
| | - Qiangqiang Dong
- Department of Organic and Polymer Chemistry, Hunan Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China
| | - Qixia Bai
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou Key Laboratory for Clean Energy and Materials, Guangzhou University, Guangzhou 510006, China
| | - Jie Yuan
- School of Chemistry and Chemical Engineering, Henan Normal University Xinxiang, Xinxiang 453007, Henan, China
| | - Zhilong Jiang
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou Key Laboratory for Clean Energy and Materials, Guangzhou University, Guangzhou 510006, China
| | - Mingzhao Chen
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou Key Laboratory for Clean Energy and Materials, Guangzhou University, Guangzhou 510006, China
| | - Die Liu
- Department of Organic and Polymer Chemistry, Hunan Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China
| | - Jun Wang
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou Key Laboratory for Clean Energy and Materials, Guangzhou University, Guangzhou 510006, China
| | - Yiming Li
- Department of Organic and Polymer Chemistry, Hunan Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China
| | - Pingshan Wang
- Department of Organic and Polymer Chemistry, Hunan Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou Key Laboratory for Clean Energy and Materials, Guangzhou University, Guangzhou 510006, China
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4
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Wei Y, Zhou P, Chen X, Bao Q, Xie L. Research Progress on Organic Nanohoops/Nanogrids. ACTA CHIMICA SINICA 2023. [DOI: 10.6023/a22110480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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5
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Ashbridge Z, Fielden SDP, Leigh DA, Pirvu L, Schaufelberger F, Zhang L. Knotting matters: orderly molecular entanglements. Chem Soc Rev 2022; 51:7779-7809. [PMID: 35979715 PMCID: PMC9486172 DOI: 10.1039/d2cs00323f] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Indexed: 11/29/2022]
Abstract
Entangling strands in a well-ordered manner can produce useful effects, from shoelaces and fishing nets to brown paper packages tied up with strings. At the nanoscale, non-crystalline polymer chains of sufficient length and flexibility randomly form tangled mixtures containing open knots of different sizes, shapes and complexity. However, discrete molecular knots of precise topology can also be obtained by controlling the number, sequence and stereochemistry of strand crossings: orderly molecular entanglements. During the last decade, substantial progress in the nascent field of molecular nanotopology has been made, with general synthetic strategies and new knotting motifs introduced, along with insights into the properties and functions of ordered tangle sequences. Conformational restrictions imparted by knotting can induce allostery, strong and selective anion binding, catalytic activity, lead to effective chiral expression across length scales, binding modes in conformations efficacious for drug delivery, and facilitate mechanical function at the molecular level. As complex molecular topologies become increasingly synthetically accessible they have the potential to play a significant role in molecular and materials design strategies. We highlight particular examples of molecular knots to illustrate why these are a few of our favourite things.
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Affiliation(s)
- Zoe Ashbridge
- Department of Chemistry, The University of Manchester, Manchester, UK
| | | | - David A Leigh
- Department of Chemistry, The University of Manchester, Manchester, UK
- School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, China
| | - Lucian Pirvu
- Department of Chemistry, The University of Manchester, Manchester, UK
| | | | - Liang Zhang
- Department of Chemistry, The University of Manchester, Manchester, UK
- School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, China
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6
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Ishizuka T, Grover N, Kingsbury CJ, Kotani H, Senge MO, Kojima T. Nonplanar porphyrins: synthesis, properties, and unique functionalities. Chem Soc Rev 2022; 51:7560-7630. [PMID: 35959748 DOI: 10.1039/d2cs00391k] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Porphyrins are variously substituted tetrapyrrolic macrocycles, with wide-ranging biological and chemical applications derived from metal chelation in the core and the 18π aromatic surface. Under suitable conditions, the porphyrin framework can deform significantly from regular planar shape, owing to steric overload on the porphyrin periphery or steric repulsion in the core, among other structure modulation strategies. Adopting this nonplanar porphyrin architecture allows guest molecules to interact directly with an exposed core, with guest-responsive and photoactive electronic states of the porphyrin allowing energy, information, atom and electron transfer within and between these species. This functionality can be incorporated and tuned by decoration of functional groups and electronic modifications, with individual deformation profiles adapted to specific key sensing and catalysis applications. Nonplanar porphyrins are assisting breakthroughs in molecular recognition, organo- and photoredox catalysis; simultaneously bio-inspired and distinctly synthetic, these molecules offer a new dimension in shape-responsive host-guest chemistry. In this review, we have summarized the synthetic methods and design aspects of nonplanar porphyrin formation, key properties, structure and functionality of the nonplanar aromatic framework, and the scope and utility of this emerging class towards outstanding scientific, industrial and environmental issues.
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Affiliation(s)
- Tomoya Ishizuka
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba and CREST (JST), 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571, Japan.
| | - Nitika Grover
- School of Chemistry, Chair of Organic Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Christopher J Kingsbury
- School of Chemistry, Chair of Organic Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Hiroaki Kotani
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba and CREST (JST), 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571, Japan.
| | - Mathias O Senge
- Institute for Advanced Study (TUM-IAS), Technical University of Munich, Focus Group - Molecular and Interfacial Engineering of Organic Nanosystems, Lichtenbergstrasse 2a, 85748 Garching, Germany.
| | - Takahiko Kojima
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba and CREST (JST), 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571, Japan.
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7
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Ashbridge Z, Kreidt E, Pirvu L, Schaufelberger F, Stenlid JH, Abild-Pedersen F, Leigh DA. Vernier template synthesis of molecular knots. Science 2022; 375:1035-1041. [PMID: 35239374 DOI: 10.1126/science.abm9247] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Molecular knots are often prepared using metal helicates to cross the strands. We found that coordinatively mismatching oligodentate ligands and metal ions provides a more effective way to synthesize larger knots using Vernier templating. Strands composed of different numbers of tridentate 2,6-pyridinedicarboxamide groups fold around nine-coordinate lanthanide (III) ions to generate strand-entangled complexes with the lowest common multiple of coordination sites for the ligand strands and metal ions. Ring-closing olefin metathesis then completes the knots. A 3:2 (ditopic strand:metal) Vernier assembly produces +31#+31 and -31#-31 granny knots. Vernier complexes of 3:4 (tetratopic strand:metal) stoichiometry selectively form a 378-atom-long trefoil-of-trefoils triskelion knot with 12 alternating strand crossings or, by using opposing stereochemistry at the terminus of the strand, an inverted-core triskelion knot with six alternating and six nonalternating strand crossings.
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Affiliation(s)
- Zoe Ashbridge
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Elisabeth Kreidt
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Lucian Pirvu
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | | | - Joakim Halldin Stenlid
- SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA.,SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Frank Abild-Pedersen
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - David A Leigh
- Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.,School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
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8
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Selinger AJ, Cavallin NA, Yanai A, Birol I, Hof F. Template‐Directed Synthesis of Bivalent, Broad‐Spectrum Hosts for Neuromuscular Blocking Agents**. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202113235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Allison J. Selinger
- Department of Chemistry University of Victoria 3800 Finnerty Rd. Victoria BC V8P 5C2 Canada
- Centre for Advanced Materials and Related Technology (CAMTEC) University of Victoria 3800 Finnerty Rd. Victoria BC V8W 2Y2 Canada
| | - Natalie A. Cavallin
- Department of Chemistry University of Victoria 3800 Finnerty Rd. Victoria BC V8P 5C2 Canada
- Centre for Advanced Materials and Related Technology (CAMTEC) University of Victoria 3800 Finnerty Rd. Victoria BC V8W 2Y2 Canada
| | - Anat Yanai
- Canada's Michael Smith Genome Sciences Centre BC Cancer Vancouver BC V5Z 4S6 Canada
| | - Inanc Birol
- Canada's Michael Smith Genome Sciences Centre BC Cancer Vancouver BC V5Z 4S6 Canada
- Department of Medical Genetics University of British Columbia Vancouver BC V6T 1Z3 Canada
| | - Fraser Hof
- Department of Chemistry University of Victoria 3800 Finnerty Rd. Victoria BC V8P 5C2 Canada
- Centre for Advanced Materials and Related Technology (CAMTEC) University of Victoria 3800 Finnerty Rd. Victoria BC V8W 2Y2 Canada
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9
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Selinger AJ, Cavallin NA, Yanai A, Birol I, Hof F. Template-Directed Synthesis of Bivalent, Broad-Spectrum Hosts for Neuromuscular Blocking Agents*. Angew Chem Int Ed Engl 2021; 61:e202113235. [PMID: 34889016 DOI: 10.1002/anie.202113235] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Indexed: 12/19/2022]
Abstract
We report on the synthesis of bivalent water-soluble calix[4]arene and calix[5]arene hosts, Super-sCx4 and Super-sCx5 as new broad-spectrum supramolecular binders of neuromuscular blocking agents (NMBAs). Synthesis was achieved using the target bisquaternary amine NMBAs as a template to link two highly anionic p-sulfonatocalixarene building blocks in aqueous solution. Bivalent anionic hosts Super-sCx4 and Super-sCx5 bind by engaging both quaternary amines present on a variety of NMBAs. We report low μM binding to structurally diverse alkyl, steroidal, curarine and benzylisoquinoline NMBAs with high selectivity over the neurotransmitter acetylcholine and a variety of other hydrophobic amines.
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Affiliation(s)
- Allison J Selinger
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd., Victoria, BC V8P 5C2, Canada.,Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, 3800 Finnerty Rd., Victoria, BC V8W 2Y2, Canada
| | - Natalie A Cavallin
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd., Victoria, BC V8P 5C2, Canada.,Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, 3800 Finnerty Rd., Victoria, BC V8W 2Y2, Canada
| | - Anat Yanai
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, BC V5Z 4S6, Canada
| | - Inanc Birol
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, BC V5Z 4S6, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Fraser Hof
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd., Victoria, BC V8P 5C2, Canada.,Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, 3800 Finnerty Rd., Victoria, BC V8W 2Y2, Canada
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10
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Jirásek M, Anderson HL, Peeks MD. From Macrocycles to Quantum Rings: Does Aromaticity Have a Size Limit? Acc Chem Res 2021; 54:3241-3251. [PMID: 34347441 DOI: 10.1021/acs.accounts.1c00323] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
ConspectusThe ring currents of aromatic and antiaromatic molecules are remarkable emergent phenomena. A ring current is a quantum-mechanical feature of the whole system, and its existence cannot be inferred from the properties of the individual components of the ring. Hückel's rule states that when an aromatic molecule with a circuit of [4n + 2] π electrons is placed in a magnetic field, the field induces a ring current that creates a magnetic field opposing the external field inside the ring. In contrast, antiaromatic rings with 4n π electrons exhibit ring currents in the opposite direction. This rule bears the name of Erich Hückel, and it grew from his molecular orbital theory, but modern formulations of Hückel's rule incorporate contributions from others, particularly William Doering and Ronald Breslow. It is often assumed that aromaticity is restricted to small molecular rings with up to about 22 π electrons. This Account outlines the discovery of global ring currents in large macrocycles with circuits of up to 162 π electrons. The largest aromatic rings yet investigated are cyclic porphyrin oligomers, which exhibit global ring currents after oxidation, reduction or optical excitation but not in the neutral ground state. The global aromaticity in these porphyrin nanorings leads to experimentally measurable aromatic stabilization energies in addition to magnetic effects that can be studied by NMR spectroscopy. Wheel-like templates can be bound inside these nanorings, providing excellent control over the molecular geometry and allowing the magnetic shielding to be probed inside the nanoring. The ring currents in these systems are well-reproduced by density functional theory (DFT), although the choice of DFT functional often turns out to be critical. Here we review recent contributions to this field and present a simple method for determining the ring current susceptibility (in nA/T) in any aromatic or antiaromatic ring from experimental NMR data by classical Biot-Savart calculations. We use this method to quantify the ring currents in a variety of aromatic rings. This survey confirms that Hückel's rule reliably predicts the direction of the ring current, and it reveals that the ring current susceptibility is surprisingly insensitive to the size of the ring. The investigation of aromaticity in even larger molecular rings is interesting because ring currents are also observed when mesoscopic metal rings are placed in a magnetic field at low temperatures. The striking similarity between the ring currents in molecules and mesoscopic metal rings arises because the effects have a common origin: a field-dependent phase shift in the electronic wave function. The main difference is that the magnetic flux through mesoscopic rings is much greater because of their larger areas, so their persistent currents are nonlinear and oscillatory with the applied field, whereas the flux through aromatic molecules is so small that their response is approximately linear in the applied field. We discuss how nonlinearity is expected to emerge in large molecular nanorings at high magnetic fields. The insights from this work are fundamentally important for understanding aromaticity and for bridging the gap between chemistry and mesoscopic physics, potentially leading to new functions in molecular electronics.
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Affiliation(s)
- Michael Jirásek
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
- Laboratory of Organic Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K
| | - Martin D Peeks
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
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11
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Senge MO, Sergeeva NN, Hale KJ. Classic highlights in porphyrin and porphyrinoid total synthesis and biosynthesis. Chem Soc Rev 2021; 50:4730-4789. [PMID: 33623938 DOI: 10.1039/c7cs00719a] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Porphyrins feature prominently in nature, be it as enzymatic cofactors, electron and exciton shuffles, as photoactive dyes, or as signaling substances. Their involvement in the generation, storage and use of oxygen is pivotal to life, while their photochemical properties are central to the biochemical functioning of plants. When complexed to metals, porphyrins can engage in a multitude of contemporary applications ranging from solar energy generation to serving as catalysts for important chemical reactions. They are also able to function as useful theranostic agents, and as novel materials for a wide range of applications. As such, they are widely considered to be highly valuable molecules, and it almost goes without saying that synthetic organic chemistry has dramatically underpinned all the key advances made, by providing reliable access to them. In fact, strategies for the synthesis of functionalized porphyrins have now reached a state of refinement where pretty well any desired porphyrin can successfully be synthesized with the approaches that are available, including a cornucopia of related macrocycle-modified porphyrinoids. In this review, we are going to illustrate the development of this exciting field by discussing a number of classic syntheses of porphyrins. Our coverage will encompass the natural protoporphyrins and chlorophylls, while also covering general strategies for the synthesis of unsymmetrical porphyrins and chlorins. Various industrial syntheses of porphyrins will also be discussed, as will other routes of great practical importance, and avenues to key porphyrinoids with modified macrocycles. A range of selected examples of contemporary functionalization reactions will be highlighted. The various key syntheses will be described and analyzed from a traditional mechanistic organic chemistry perspective to help student readers, and those who are new to this area. The aim will be to allow readers to mechanistically appreciate and understand how many of these fascinating ring-systems are built and further functionalized.
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Affiliation(s)
- Mathias O Senge
- School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin 2, Ireland.
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12
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Judd CJ, Nizovtsev AS, Plougmann R, Kondratuk DV, Anderson HL, Besley E, Saywell A. Molecular Quantum Rings Formed from a π-Conjugated Macrocycle. PHYSICAL REVIEW LETTERS 2020; 125:206803. [PMID: 33258651 DOI: 10.1103/physrevlett.125.206803] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 09/22/2020] [Indexed: 06/12/2023]
Abstract
The electronic structure of a molecular quantum ring (stacks of 40-unit cyclic porphyrin polymers) is characterized via scanning tunneling microscopy and scanning tunneling spectroscopy. Our measurements access the energetic and spatial distribution of the electronic states and, utilizing a combination of density functional theory and tight-binding calculations, we interpret the experimentally obtained electronic structure in terms of coherent quantum states confined around the circumference of the π-conjugated macrocycle. These findings demonstrate that large (53 nm circumference) cyclic porphyrin polymers have the potential to act as molecular quantum rings.
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Affiliation(s)
- Chris J Judd
- School of Physics & Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Anton S Nizovtsev
- School of Chemistry, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Academician Lavrentiev Avenue 3, 630090 Novosibirsk, Russian Federation
- Novosibirsk State University, Pirogova Street 2, 630090 Novosibirsk, Russian Federation
| | - Rikke Plougmann
- School of Physics & Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Dmitry V Kondratuk
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Elena Besley
- School of Chemistry, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Alex Saywell
- School of Physics & Astronomy, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
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13
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Bols PS, Rickhaus M, Tejerina L, Gotfredsen H, Eriksen K, Jirasek M, Anderson HL. Allosteric Cooperativity and Template-Directed Synthesis with Stacked Ligands in Porphyrin Nanorings. J Am Chem Soc 2020; 142:13219-13226. [PMID: 32633124 DOI: 10.1021/jacs.0c06269] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The link between allosteric cooperativity and template-directed synthesis has been investigated by studying complexes in which two oligopyridine ligands bind inside a zinc porphyrin nanoring in a stacked arrangement. The binding of a 6-porphyrin nanoring to two tridentate ligands (with s-triazine or benzene cores) occurs with high negative allosteric cooperativity (α ≈ 10-3-10-4). Formation constants for 1:1 and 1:2 complexes were determined by UV-vis-NIR denaturation titration, using pyridine as a competing ligand, and cooperativity factors were confirmed by NMR spectroscopy. The rate constants for formation of the 1:1 and 1:2 complexes are approximately equal, and the negative cooperativity can be attributed to faster dissociation of the 1:2 complex. These tridentate ligands are not effective templates for directing the synthesis of the 6-porphyrin nanoring, in keeping with their negative cooperativity of binding. In contrast, the binding of a 12-porphyrin nanoring to two hexadentate ligands occurs with high positive allosteric cooperativity (α > 40), and the ligand is an effective Vernier template for directing the synthesis of the 12-porphyrin nanoring. This stacked Vernier template approach creates the product in an open circular conformation, which is advantageous for preparing macrocycles that do not easily adopt a figure-of-eight geometry.
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Affiliation(s)
- Pernille S Bols
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom
| | - Michel Rickhaus
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom
| | - Lara Tejerina
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom
| | - Henrik Gotfredsen
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom
| | - Kristina Eriksen
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom
| | - Michael Jirasek
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA, United Kingdom
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14
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Abstract
Aromaticity can be defined by the ability of a molecule to sustain a ring current when placed in a magnetic field. Hückel’s rule states that molecular rings with [4n+2] π-electrons are aromatic, with an induced magnetisation that opposes the external field inside the ring, whereas those with 4n π-electrons are antiaromatic, with the opposite magnetisation. This rule reliably predicts the behaviour of small molecules, typically with fewer than 22 π-electrons (n = 5). It is not clear whether aromaticity has a size limit, or whether Hückel’s rule extends to much larger macrocycles. Here, we present evidence for global aromaticity in porphyrin nanorings with circuits of up to 162 π-electrons (n = 40); aromaticity is controlled by changing the constitution, oxidation state and conformation. Whenever a ring current is observed, its direction is correctly predicted by Hückel’s rule. The largest ring currents occur when the porphyrins units have fractional oxidation states.
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15
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Miki K, Ohe K. π‐Conjugated Macrocycles Bearing Angle‐Strained Alkynes. Chemistry 2019; 26:2529-2575. [DOI: 10.1002/chem.201904114] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 10/24/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Koji Miki
- Department of Energy and Hydrocarbon ChemistryGraduate School of EngineeringKyoto University Katsura Nishikyo-ku Kyoto 615–8510 Japan
| | - Kouichi Ohe
- Department of Energy and Hydrocarbon ChemistryGraduate School of EngineeringKyoto University Katsura Nishikyo-ku Kyoto 615–8510 Japan
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16
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Ordering, flexibility and frustration in arrays of porphyrin nanorings. Nat Commun 2019; 10:2932. [PMID: 31270343 PMCID: PMC6610075 DOI: 10.1038/s41467-019-11009-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/13/2019] [Indexed: 12/01/2022] Open
Abstract
The regular packing of atoms, molecules and nanoparticles provides the basis for the understanding of structural order within condensed phases of matter. Typically the constituent particles are considered to be rigid with a fixed shape. Here we show, through a combined experimental and numerical study of the adsorption of cyclic porphyrin polymers, nanorings, on a graphite surface, that flexible molecules can exhibit a rich and complex packing behaviour. Depending on the number of porphyrin sub-units within the nanoring we observe either a highly ordered hexagonal phase or frustrated packing driven by directional interactions which for some arrangements is combined with the internal deformation of the cyclic polymer. Frustration and deformation occur in arrays of polymers with ten sub-units since close packing and co-alignment of neighbouring groups cannot be simultaneously realised for nanorings with this internal symmetry. The packing of spheres, disks and other simple shapes into arrays on surfaces is relevant to many problems across the physical sciences. Here the authors study the influence of flexibility and reduced symmetry on the packing of porphyrin nanorings which are deposited from solution onto a graphite surface.
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17
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Abstract
On-surface synthesis provides a route for the production of 1D and 2D covalently bonded polymeric structures. Such reactions are confined to the surface of a substrate and the catalytic properties of the substrate are often utilised to initiate the reaction. Recent studies have focused on the properties of various crystallographic planes of metallic substrates, as well as native surface features such as step-edges, in an effort to provide control over the pathway of the reaction and the resultant products. An alternative approach is to template the catalytic surface with a porous molecular overlayer; giving rise to well-defined surface regions within which an on-surface reaction may be confined. Here we present a methodology where macromolecular templates are used to confine an on-surface reaction. Cyclic porphyrin polymers, nanorings - consisting of 40 porphyrin units with internal diameter 13 nm, are used to form a template on a Au(111) surface, and an on-surface Ullmann-type coupling reaction is initiated within the nanoring template. The surface confined template and covalently coupled reaction products are investigated and characterised with scanning tunnelling microscopy.
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18
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Xue S, Kuzuhara D, Aratani N, Yamada H. Synthesis of a Porphyrin(2.1.2.1) Nanobelt and Its Ability To Bind Fullerene. Org Lett 2019; 21:2069-2072. [DOI: 10.1021/acs.orglett.9b00329] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Songlin Xue
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Daiki Kuzuhara
- Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan
| | - Naoki Aratani
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Hiroko Yamada
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
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19
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Đorđević L, Marangoni T, Liu M, De Zorzi R, Geremia S, Minoia A, Lazzaroni R, Ishida Y, Bonifazi D. Templating Porphyrin Anisotropy via Magnetically Aligned Carbon Nanotubes. Chempluschem 2019; 84:1270-1278. [DOI: 10.1002/cplu.201800623] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Luka Đorđević
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste Via L. Giorgieri 1 34127 Trieste Italy
| | - Tomas Marangoni
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste Via L. Giorgieri 1 34127 Trieste Italy
| | - Mingjie Liu
- RIKEN Center for Emergent Matter Science 2-1 Hirosawa, Wako Saitama 351-0198 Japan
| | - Rita De Zorzi
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste Via L. Giorgieri 1 34127 Trieste Italy
| | - Silvano Geremia
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste Via L. Giorgieri 1 34127 Trieste Italy
| | - Andrea Minoia
- Laboratory for Chemistry of Novel Materials, CIRMAPUniversité de Mons-UMONS Place du Parc 20 B-7000 Mons Belgium
| | - Roberto Lazzaroni
- Laboratory for Chemistry of Novel Materials, CIRMAPUniversité de Mons-UMONS Place du Parc 20 B-7000 Mons Belgium
| | - Yasuhiro Ishida
- RIKEN Center for Emergent Matter Science 2-1 Hirosawa, Wako Saitama 351-0198 Japan
| | - Davide Bonifazi
- School of ChemistryCardiff University Park Place Main Building CF10 3AT United Kingdom
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20
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Shokurov AV, Meshkov IN, Bulach V, Gorbunova YG, Hosseini MW, Tsivadze AY, Arslanov VV, Selektor SL. Restriction of the rotational relaxation of a butadiyne-bridged porphyrin dimer in ultrathin films. NEW J CHEM 2019. [DOI: 10.1039/c9nj01807g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A way to stabilize the less energetically viable orthogonal conformation of a porphyrin dimer by means of a forced orientation at an interface is shown.
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Affiliation(s)
- Alexander V. Shokurov
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences
- Moscow
- Russia
| | - Ivan N. Meshkov
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences
- Moscow
- Russia
| | - Véronique Bulach
- Molecular Tectonics Laboratory
- UMR UDS-CNRS
- 7140 & icFRC
- Université de Strasbourg
- Strasbourg
| | - Yulia G. Gorbunova
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences
- Moscow
- Russia
- Kurnakov Institute of General and Inorganic Chemistry
- Russian Academy of Sciences
| | - Mir Wais Hosseini
- Molecular Tectonics Laboratory
- UMR UDS-CNRS
- 7140 & icFRC
- Université de Strasbourg
- Strasbourg
| | - Aslan Yu. Tsivadze
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences
- Moscow
- Russia
- Kurnakov Institute of General and Inorganic Chemistry
- Russian Academy of Sciences
| | - Vladimir V. Arslanov
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences
- Moscow
- Russia
| | - Sofia L. Selektor
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences
- Moscow
- Russia
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21
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Saikawa M, Noda T, Matsuoka R, Nakamura T, Nabeshima T. Heterodinuclear Group 13 Element Complexes of N
4
O
6
‐Type Dipyrrin with an Unsymmetrical Twisted Structure. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201801062] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Makoto Saikawa
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS) University of Tsukuba 1‐1‐1 Tennodai, Tsukuba 305‐8571 Ibaraki Japan
| | - Takumu Noda
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS) University of Tsukuba 1‐1‐1 Tennodai, Tsukuba 305‐8571 Ibaraki Japan
| | - Ryota Matsuoka
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS) University of Tsukuba 1‐1‐1 Tennodai, Tsukuba 305‐8571 Ibaraki Japan
| | - Takashi Nakamura
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS) University of Tsukuba 1‐1‐1 Tennodai, Tsukuba 305‐8571 Ibaraki Japan
| | - Tatsuya Nabeshima
- Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS) University of Tsukuba 1‐1‐1 Tennodai, Tsukuba 305‐8571 Ibaraki Japan
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22
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Abstract
This Account is about templates as construction tools: molecules for making molecules. A template organizes the reactants and provides information to promote formation of a specific product, but it is not part of the final product. We have developed many different strategies for using oligopyridines as templates for the synthesis of alkyne-linked π-conjugated metalloporphyrin oligomers. These compounds include some of the largest macrocycles ever synthesized, such as a 50-porphyrin ring with a diameter of 21 nm containing a ring of 750 C-C bonds. Metalloporphyrins are excellent models for exploring template directed synthesis, as they can be functionalized in many different positions and the central metal (typically Zn or Mg) provides a handle for coordination to templates. Classical template-directed macrocyclization reactions have a 1:1 complementarity between the template and the product. This strategy works well for preparing nanorings of 5-7 porphyrin units, but larger templates are laborious to synthesize. Rings of 8 or more porphyrin units are most easily prepared using "nonclassical" strategies, in which several small templates work together to direct the formation of a large ring. In the Vernier approach, a mismatch between the number of binding sites on the template and the building block leads to a mathematical amplification of the length scale: the number of binding sites in the product is the lowest common multiple of those in the template and the building block. For example, a 40-porphyrin ring can be prepared by coupling a linear decamer in the presence of an octadentate template. Linear Vernier templating opens up intriguing possibilities for self-replication. When several small radial oligopyridine templates bind inside a large nanoring they can form complexes with some vacant coordination sites that display correlated motion like the caterpillar tracks of a bulldozer. These caterpillar track complexes can be used in template-directed synthesis and they provide the most convenient route to 8- and 10-porphyrin rings. Russian doll complexes provide another strategy for template-directed synthesis: a number of specifically designed ligands bind to a central nanoring to form a template for constructing a larger concentric nanoring. The same oligopyridine templates that are used to prepare nanorings can also be used to synthesize three-dimensional nanotubes and nanoballs. Again, nonclassical approaches, in which several small templates work together cooperatively, are much simpler than creating a single large template with sufficient binding sites to define the whole geometry of the product. Oligopyridine ligands can also be used as shadow mask templates to control the demetalation of magnesium porphyrin nanorings, because metal centers that are not coordinated by the template can be selectively demetalated with acid. Thus, the template forms a permanent shadow on the porphyrin nanostructure that remains after the template has been removed. Shadow mask templates provide a simple route to heterometalated molecular architectures. The insights emerging from these studies are widely applicable, and there are many opportunities for inventing new ways of using templates to control reactions.
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Affiliation(s)
- Pernille S. Bols
- Chemistry Research Laboratory, Department of Chemistry, Oxford University, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Harry L. Anderson
- Chemistry Research Laboratory, Department of Chemistry, Oxford University, Mansfield Road, Oxford OX1 3TA, United Kingdom
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23
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Morley DO, Malfois M, Kamonsutthipaijit N, Kondratuk DV, Anderson HL, Wilson M. A Coarse-Grained Model for Free and Template-Bound Porphyrin Nanorings. J Phys Chem A 2017; 121:5907-5920. [PMID: 28703593 DOI: 10.1021/acs.jpca.7b05279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Coarse-grained simulation models are developed to study both template-bound and free porphyrin nanoring systems. Key interactions are modeled with relatively simple (and physically motivated) energy functions which allow for relatively facile transfer both between different ring sizes and between the template-bound and free nanoring systems. The effects of varying the model parameters on the respective radii of gyration are determined. The effects of including different templates on the ring structure are investigated both in terms of the detailed geometry of the template and the interaction strength between the template and the metal centers in the nanorings. The role of the template-nanoring interaction strength in controlling potential "caterpillar track" rotational motion is discussed. The relationship of the model to experimental small-angle X-ray, exchange spectroscopy, and electron spin resonance results is discussed.
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Affiliation(s)
- David Ormrod Morley
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, U.K
| | - Marc Malfois
- Diamond Light Source Ltd , Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K
| | - Nuntaporn Kamonsutthipaijit
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory , Mansfield Road, Oxford OX1 3TA, U.K
| | - Dmitry V Kondratuk
- Diamond Light Source Ltd , Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory , Mansfield Road, Oxford OX1 3TA, U.K
| | - Mark Wilson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, U.K
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24
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Kamonsutthipaijit N, Anderson HL. Template-directed synthesis of linear porphyrin oligomers: classical, Vernier and mutual Vernier. Chem Sci 2017; 8:2729-2740. [PMID: 28553508 PMCID: PMC5426366 DOI: 10.1039/c6sc05355f] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 01/20/2017] [Indexed: 12/22/2022] Open
Abstract
We demonstrate a variety of template-directed strategies for preparing linear monodisperse butadiyne-linked porphyrin oligomers by Glaser–Hay coupling, based on the coordination of pyridine-substituted nickel(ii) porphyrins to zinc(ii) porphyrins.
Three different types of template-directed syntheses of linear porphyrin oligomers are presented. In the classical approach the product has the same number of binding sites as the template, whereas in Vernier reactions the product has the lowest common multiple of the numbers of binding sites in the template and the building block. Mutual Vernier templating is like Vernier templating except that both strands of the Vernier complex undergo coupling simultaneously, so that it becomes impossible to say which is the ‘template’ and which is the ‘building block’. The template-directed synthesis of monodisperse linear oligomers is more difficult than that of cyclic oligomers, because the products of linear templating have reactive ends. All three types of templating are demonstrated here, and used to prepare a nickel(ii) porphyrin dodecamer with 4-pyridyl substituents on all twelve porphyrin units. The stabilities and cooperativities of the double-strand complexes involved in these reactions were investigated by UV-vis-NIR titration. The four-rung ladder duplex has a stability constant of about 2 × 1018 M–1 in dichloromethane at 298 K.
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Affiliation(s)
| | - Harry L Anderson
- Department of Chemistry , University of Oxford , Chemistry Research Laboratory , Oxford OX1 3TA , UK .
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25
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von Krbek LKS, Schalley CA, Thordarson P. Assessing cooperativity in supramolecular systems. Chem Soc Rev 2017; 46:2622-2637. [DOI: 10.1039/c7cs00063d] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In this tutorial review, different aspects of cooperativity in supramolecular chemistry and their thermodynamic analysis are discussed.
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Affiliation(s)
| | | | - Pall Thordarson
- School of Chemistry
- The Australian Centre for Nanomedicine and the ARC Centre of Excellence in Convergent Bio-Nano Science and Technology
- University of New South Wales
- Australia
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26
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Yu C, Long H, Jin Y, Zhang W. Synthesis of Cyclic Porphyrin Trimers through Alkyne Metathesis Cyclooligomerization and Their Host-Guest Binding Study. Org Lett 2016; 18:2946-9. [PMID: 27267936 DOI: 10.1021/acs.orglett.6b01293] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclic porphyrin trimers were synthesized through one-step cyclooligomerization via alkyne metathesis from diyne monomers. These macrocycles show interesting host-guest binding interactions with fullerenes, selectively binding C70 (6 × 10(3) M(-1)) over C60 and C84 (no binding observed). The fullerene-encapsulated host-guest complex can undergo guest or host exchange in the presence of another guest (2,4,6-tri(4-pyridyl)-1,3,5-triazine) or host (cage COP5) molecule with higher binding affinity.
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Affiliation(s)
- Chao Yu
- Department of Chemistry and Biochemistry, University of Colorado Boulder , Boulder, Colorado 80309, United States
| | - Hai Long
- National Renewable Energy Laboratory , Golden, Colorado 80401, United States
| | - Yinghua Jin
- Department of Chemistry and Biochemistry, University of Colorado Boulder , Boulder, Colorado 80309, United States
| | - Wei Zhang
- Department of Chemistry and Biochemistry, University of Colorado Boulder , Boulder, Colorado 80309, United States
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27
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Jiang X, O’Brien ZJ, Yang S, Lai LH, Buenaflor J, Tan C, Khan S, Houk KN, Garcia-Garibay MA. Crystal Fluidity Reflected by Fast Rotational Motion at the Core, Branches, and Peripheral Aromatic Groups of a Dendrimeric Molecular Rotor. J Am Chem Soc 2016; 138:4650-6. [PMID: 26973017 PMCID: PMC5155508 DOI: 10.1021/jacs.6b01398] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Low packing densities are key structural features of amphidynamic crystals built with static and mobile components. Here we report a loosely packed crystal of dendrimeric rotor 2 and the fast dynamics of all its aromatic groups, both resulting from the hyperbranched structure of the molecule. Compound 2 was synthesized with a convergent strategy to construct a central phenylene core with stators consisting of two layers of triarylmethyl groups. Single crystal X-ray diffraction analysis confirmed a low-density packing structure consisting of one molecule of 2 and approximately eight solvent molecules per unit cell. Three isotopologues of 2 were synthesized to study the motion of each segment of the molecule in the solid state using variable temperature quadrupolar echo (2)H NMR spectroscopy. Line shape analysis of the spectra reveals that the central phenylene, the six branch phenylenes, and the 18 periphery phenyls all display megahertz rotational dynamics in the crystals at ambient temperature. Arrhenius analysis of the data gives similar activation energies and pre-exponential factors for different parts of the structure. The observed pre-exponential factors are 4-6 orders of magnitude greater than those of elementary site-exchange processes, indicating that the dynamics are not dictated by static energetic potentials. Instead, the activation energies for rotations in the crystals of 2 are controlled by temperature dependent local structural fluctuations and crystal fluidity.
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Affiliation(s)
- Xing Jiang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Zachary J. O’Brien
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Song Yang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Lan Huong Lai
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Jeffrey Buenaflor
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Colleen Tan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Saeed Khan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - K. N. Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Miguel A. Garcia-Garibay
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
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28
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Lungerich D, Reger D, Hölzel H, Riedel R, Martin MMJC, Hampel F, Jux N. Eine Strategie zur Synthese ungewöhnlicher Hexaarylbenzole im Multigramm‐Maßstab. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201600841] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Dominik Lungerich
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestraße 42 91054 Erlangen Deutschland
| | - David Reger
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestraße 42 91054 Erlangen Deutschland
| | - Helen Hölzel
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestraße 42 91054 Erlangen Deutschland
| | - René Riedel
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestraße 42 91054 Erlangen Deutschland
| | - Max M. J. C. Martin
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestraße 42 91054 Erlangen Deutschland
| | - Frank Hampel
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestraße 42 91054 Erlangen Deutschland
| | - Norbert Jux
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestraße 42 91054 Erlangen Deutschland
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29
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Lungerich D, Reger D, Hölzel H, Riedel R, Martin MMJC, Hampel F, Jux N. A Strategy towards the Multigram Synthesis of Uncommon Hexaarylbenzenes. Angew Chem Int Ed Engl 2016; 55:5602-5. [DOI: 10.1002/anie.201600841] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Dominik Lungerich
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestrasse 42 91054 Erlangen Germany
| | - David Reger
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestrasse 42 91054 Erlangen Germany
| | - Helen Hölzel
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestrasse 42 91054 Erlangen Germany
| | - René Riedel
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestrasse 42 91054 Erlangen Germany
| | - Max M. J. C. Martin
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestrasse 42 91054 Erlangen Germany
| | - Frank Hampel
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestrasse 42 91054 Erlangen Germany
| | - Norbert Jux
- Department Chemie und Pharmazie & Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Henkestrasse 42 91054 Erlangen Germany
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30
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Wang SP, Shen YF, Zhu BY, Wu J, Li S. Recent advances in the template-directed synthesis of porphyrin nanorings. Chem Commun (Camb) 2016; 52:10205-16. [DOI: 10.1039/c6cc04556a] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
This Feature Article reviews recent advances in the template-directed synthesis of porphyrin nanorings, including new templating methods, novel structures, and their applications in host–guest chemistry and artificial light-harvesting.
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Affiliation(s)
- Shu-Ping Wang
- College of Material
- Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Yan-Feng Shen
- College of Material
- Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Ben-Yue Zhu
- College of Material
- Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Jing Wu
- College of Material
- Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
| | - Shijun Li
- College of Material
- Chemistry and Chemical Engineering
- Hangzhou Normal University
- Hangzhou 310036
- P. R. China
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31
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Jiang HW, Tanaka T, Kim T, Sung YM, Mori H, Kim D, Osuka A. Synthesis of [n]Cyclo-5,15-porphyrinylene-4,4′-biphenylenes Displaying Size-Dependent Excitation-Energy Hopping. Angew Chem Int Ed Engl 2015; 54:15197-201. [DOI: 10.1002/anie.201507822] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Indexed: 11/08/2022]
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32
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Jiang HW, Tanaka T, Kim T, Sung YM, Mori H, Kim D, Osuka A. Synthesis of [n]Cyclo-5,15-porphyrinylene-4,4′-biphenylenes Displaying Size-Dependent Excitation-Energy Hopping. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507822] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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33
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Katoono R, Tanaka Y, Kusaka K, Fujiwara K, Suzuki T. Dynamic Figure Eight Chirality: Multifarious Inversions of a Helical Preference Induced by Complexation. J Org Chem 2015; 80:7613-25. [DOI: 10.1021/acs.joc.5b01206] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ryo Katoono
- Department of Chemistry,
Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Yuki Tanaka
- Department of Chemistry,
Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Keiichi Kusaka
- Department of Chemistry,
Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Kenshu Fujiwara
- Department of Chemistry,
Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Takanori Suzuki
- Department of Chemistry,
Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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34
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Parois P, Cooper RI, Thompson AL. Crystal structures of increasingly large molecules: meeting the challenges with CRYSTALS software. Chem Cent J 2015; 9:30. [PMID: 26029252 PMCID: PMC4448882 DOI: 10.1186/s13065-015-0105-4] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 05/13/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The size and complexity of molecules being studied by single crystal diffraction is growing year by year, resulting in an increase in the difficulties encountered during structure determination. From the crystallisation itself and sample handling, to structure solution and refinement, specific problems due to larger molecules are discussed. RESULTS During refinement, several methods are available to deal with the problems encountered with large structures within the software Crystals. Hydrogens atoms can neither be found easily nor refined freely, but restraints can be applied automatically. Special scattering factors can be used to model complex disorder. Finally chemical information can be included in the form of restraints in order to help the determination of a good model. Multicollinearity problems are more likely in the refinement of large structures; to some extent more precise and accurate algorithms can help. Also, if the global minimum is less well defined, faster refinement enables more cycles to be carried out, a necessity for good convergence. The efficiency of the algorithms in Crystals have been increased to help address these issues. CONCLUSIONS Thus, crystal structures are getting larger and their complexity is increasing. Recent developments in precision and speed during the least squares in Crystals is helping the structural scientist to deal with larger structures more efficiently.
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Affiliation(s)
- Pascal Parois
- Chemical Crystallography, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA UK
| | - Richard I Cooper
- Chemical Crystallography, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA UK
| | - Amber L Thompson
- Chemical Crystallography, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA UK
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35
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Liu S, Kondratuk DV, Rousseaux SAL, Gil-Ramírez G, O'Sullivan MC, Cremers J, Claridge TDW, Anderson HL. Caterpillar track complexes in template-directed synthesis and correlated molecular motion. Angew Chem Int Ed Engl 2015; 54:5355-9. [PMID: 25683453 PMCID: PMC4471551 DOI: 10.1002/anie.201412293] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 01/29/2015] [Indexed: 01/05/2023]
Abstract
Small alterations to the structure of a star-shaped template totally change its mode of operation. The hexapyridyl template directs the conversion of a porphyrin dimer to the cyclic hexamer, but deleting one pyridine site changes the product to the cyclic decamer, while deleting two binding sites changes the product to the cyclic octamer. This surprising switch in selectivity is explained by the formation of 2:1 caterpillar track complexes, in which two template wheels bind inside the nanoring. Caterpillar track complexes can also be prepared by binding the hexapyridyl template inside the 8- and 10-porphyrin nanorings. NMR exchange spectroscopy (EXSY) experiments show that these complexes exhibit correlated motion, in which the conrotatory rotation of the two template wheels is coupled to rotation of the nanoring track. In the case of the 10-porphyrin system, the correlated motion can be locked by binding palladium(II) dichloride between the two templates.
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Affiliation(s)
- Shiqi Liu
- Department of Chemistry, University of Oxford, Chemistry Research LaboratoryOxford, OX1 3TA (UK)
| | - Dmitry V Kondratuk
- Department of Chemistry, University of Oxford, Chemistry Research LaboratoryOxford, OX1 3TA (UK)
| | - Sophie A L Rousseaux
- Department of Chemistry, University of Oxford, Chemistry Research LaboratoryOxford, OX1 3TA (UK)
| | - Guzmán Gil-Ramírez
- Department of Chemistry, University of Oxford, Chemistry Research LaboratoryOxford, OX1 3TA (UK)
| | - Melanie C O'Sullivan
- Department of Chemistry, University of Oxford, Chemistry Research LaboratoryOxford, OX1 3TA (UK)
| | - Jonathan Cremers
- Department of Chemistry, University of Oxford, Chemistry Research LaboratoryOxford, OX1 3TA (UK)
| | - Tim D W Claridge
- Department of Chemistry, University of Oxford, Chemistry Research LaboratoryOxford, OX1 3TA (UK)
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Chemistry Research LaboratoryOxford, OX1 3TA (UK)
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36
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Liu S, Kondratuk DV, Rousseaux SAL, Gil‐Ramírez G, O'Sullivan MC, Cremers J, Claridge TDW, Anderson HL. Caterpillar Track Complexes in Template-Directed Synthesis and Correlated Molecular Motion. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 127:5445-5449. [PMID: 27546919 PMCID: PMC4974918 DOI: 10.1002/ange.201412293] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 01/29/2015] [Indexed: 01/03/2023]
Abstract
Small alterations to the structure of a star-shaped template totally change its mode of operation. The hexapyridyl template directs the conversion of a porphyrin dimer to the cyclic hexamer, but deleting one pyridine site changes the product to the cyclic decamer, while deleting two binding sites changes the product to the cyclic octamer. This surprising switch in selectivity is explained by the formation of 2:1 caterpillar track complexes, in which two template wheels bind inside the nanoring. Caterpillar track complexes can also be prepared by binding the hexapyridyl template inside the 8- and 10-porphyrin nanorings. NMR exchange spectroscopy (EXSY) experiments show that these complexes exhibit correlated motion, in which the conrotatory rotation of the two template wheels is coupled to rotation of the nanoring track. In the case of the 10-porphyrin system, the correlated motion can be locked by binding palladium(II) dichloride between the two templates.
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Affiliation(s)
- Shiqi Liu
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA (UK)
| | - Dmitry V. Kondratuk
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA (UK)
| | - Sophie A. L. Rousseaux
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA (UK)
| | - Guzmán Gil‐Ramírez
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA (UK)
| | - Melanie C. O'Sullivan
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA (UK)
| | - Jonathan Cremers
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA (UK)
| | - Tim D. W. Claridge
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA (UK)
| | - Harry L. Anderson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, OX1 3TA (UK)
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37
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Gong JQ, Parkinson P, Kondratuk D, Gil-Ramírez G, Anderson HL, Herz LM. Structure-Directed Exciton Dynamics in Templated Molecular Nanorings. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2015; 119:6414-6420. [PMID: 25960822 PMCID: PMC4418736 DOI: 10.1021/acs.jpcc.5b00210] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 02/26/2015] [Indexed: 06/04/2023]
Abstract
Conjugated polymers with cyclic structures are interesting because their symmetry leads to unique electronic properties. Recent advances in Vernier templating now allow large shape-persistent fully conjugated porphyrin nanorings to be synthesized, exhibiting unique electronic properties. We examine the impact of different conformations on exciton delocalization and emission depolarization in a range of different porphyrin nanoring topologies with comparable spatial extent. Low photoluminescence anisotropy values are found to occur within the first few hundred femtoseconds after pulsed excitation, suggesting ultrafast delocalization of excitons across the nanoring structures. Molecular dynamics simulations show that further polarization memory loss is caused by out-of-plane distortions associated with twisting and bending of the templated nanoring topologies.
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Affiliation(s)
- Juliane Q. Gong
- Department
of Physics, Clarendon Laboratory, University
of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Patrick Parkinson
- Department
of Physics, Clarendon Laboratory, University
of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Dmitry
V. Kondratuk
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Guzmán Gil-Ramírez
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Harry L. Anderson
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Laura M. Herz
- Department
of Physics, Clarendon Laboratory, University
of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
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38
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Parkinson P, Kondratuk DV, Menelaou C, Gong JQ, Anderson HL, Herz LM. Chromophores in Molecular Nanorings: When Is a Ring a Ring? J Phys Chem Lett 2014; 5:4356-4361. [PMID: 26273987 DOI: 10.1021/jz5022153] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The topology of a conjugated molecule plays a significant role in controlling both the electronic properties and the conformational manifold that the molecule may explore. Fully π-conjugated molecular nanorings are of particular interest, as their lowest electronic transition may be strongly suppressed as a result of symmetry constraints. In contrast, the simple Kasha model predicts an enhancement in the radiative rate for corresponding linear oligomers. Here we investigate such effects in linear and cyclic conjugated molecules containing between 6 and 42 butadiyne-linked porphyrin units (corresponding to 600 C-C bonds) as pure monodisperse oligomers. We demonstrate that as the diameter of the nanorings increases beyond ∼10 nm, its electronic properties tend toward those of a similarly sized linear molecule as a result of excitation localization on a subsegment of the ring. However, significant differences persist in the nature of the emitting dipole polarization even beyond this limit, arising from variations in molecular curvature and conformation.
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Affiliation(s)
- Patrick Parkinson
- †Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Dmitry V Kondratuk
- ‡Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Christopher Menelaou
- †Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Juliane Q Gong
- †Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Harry L Anderson
- ‡Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Laura M Herz
- †Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
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