1
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Lemon CM, Powers DC, Huynh M, Maher AG, Phillips AA, Tripet BP, Nocera DG. Ag(III)···Ag(III) Argentophilic Interaction in a Cofacial Corrole Dyad. Inorg Chem 2023; 62:3-17. [PMID: 36538590 DOI: 10.1021/acs.inorgchem.2c02285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Metallophilic interactions between closed-shell metal centers are exemplified by d10 ions, with Au(I) aurophilic interactions as the archetype. Such an interaction extends to d8 species, and examples involving Au(III) are prevalent. Conversely, Ag(III) argentophilic interactions are uncommon. Here, we identify argentophilic interactions in silver corroles, which are authentic Ag(III) species. The crystal structure of a monomeric silver corrole is a dimer in the solid state, and the macrocycle exhibits an atypical domed conformation. In order to evaluate whether this represents an authentic metallophilic interaction or a crystal-packing artifact, the analogous cofacial or "pacman" corrole was prepared. The conformation of the monomer was recapitulated in the silver pacman corrole, exhibiting a short 3.67 Å distance between metal centers and a significant compression of the xanthene backbone. Theoretical calculations support the presence of a rare Ag(III)···Ag(III) argentophilic interaction in the pacman complex.
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Affiliation(s)
- Christopher M Lemon
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States.,Department of Chemistry and Biochemistry, Montana State University (MSU), P.O. Box 173400, Bozeman, Montana 59717, United States
| | - David C Powers
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Michael Huynh
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Andrew G Maher
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Austin A Phillips
- Department of Chemistry and Biochemistry, Montana State University (MSU), P.O. Box 173400, Bozeman, Montana 59717, United States
| | - Brian P Tripet
- Department of Chemistry and Biochemistry, Montana State University (MSU), P.O. Box 173400, Bozeman, Montana 59717, United States
| | - Daniel G Nocera
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
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2
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Ke XS, Kim T, He Q, Lynch VM, Kim D, Sessler JL. Three-Dimensional Fully Conjugated Carbaporphyrin Cage. J Am Chem Soc 2018; 140:16455-16459. [PMID: 30452259 DOI: 10.1021/jacs.8b11158] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A fully conjugated three-dimensional (3D) expanded carbaporphyrin (2) was prepared in a one-pot procedure that involves a [2+4] condensation reaction between a dibenzo[ g, p]chrysene-bearing tetrapyrrole precursor (1) and pentafluorobenzaldehyde, followed by oxidation. Single crystal X-ray diffraction analysis revealed that 2 possesses a cage-like structure consisting of four dipyrromethenes and two bridging dibenzo[ g, p]chrysene units. As prepared, 2 is nonaromatic as inferred from UV-vis-NIR and 1H NMR spectroscopy and a near-zero (-1.75) nucleus-independent chemical shift (NICS) value. In contrast, after protonation with trifluoroacetic acid (TFA), the cage gains global aromatic character as inferred from the large negative NICS value (-11.63) and diatropic ring current observed in the anisotropy of the induced current density (ACID) plot, as well as the ca. 8-fold increase in the excited state lifetime. In addition, the size of the cavity increases to ca. 143 Å3 upon protonation as deduced from a single crystal X-ray diffraction analysis. To our knowledge, this is the largest carbaporphyrin prepared to date and the first with a fully conjugated 3D cage structure whose size and electronic features may be tuned through protonation.
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Affiliation(s)
- Xian-Sheng Ke
- Department of Chemistry , The University of Texas at Austin , Austin , Texas 78712-1224 , United States
| | - Taeyeon Kim
- Department of Chemistry , Yonsei University , Seoul 03722 , Korea
| | - Qing He
- Department of Chemistry , The University of Texas at Austin , Austin , Texas 78712-1224 , United States
| | - Vincent M Lynch
- Department of Chemistry , The University of Texas at Austin , Austin , Texas 78712-1224 , United States
| | - Dongho Kim
- Department of Chemistry , Yonsei University , Seoul 03722 , Korea
| | - Jonathan L Sessler
- Department of Chemistry , The University of Texas at Austin , Austin , Texas 78712-1224 , United States
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3
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Sarma T, Kim G, Sen S, Cha WY, Duan Z, Moore MD, Lynch VM, Zhang Z, Kim D, Sessler JL. Proton-Coupled Redox Switching in an Annulated π-Extended Core-Modified Octaphyrin. J Am Chem Soc 2018; 140:12111-12119. [PMID: 30180553 DOI: 10.1021/jacs.8b06938] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Proton-coupled electron transfer (PCET) is an important chemical and biological phenomenon. It is attractive as an on-off switching mechanism for redox-active synthetic systems but has not been extensively exploited for this purpose. Here we report a core-modified planar weakly antiaromatic/nonaromatic octaphyrin, namely, a [32]octaphyrin(1.0.1.0.1.0.1.0) (1) derived from rigid naphthobipyrrole and dithienothiophene (DTT) precursors, that undergoes proton-coupled two-electron reduction to produce its aromatic congener in the presence of HCl and other hydrogen halides. Evidence for the production of a [4 n + 1] π-electron intermediate radical state is seen in the presence of trifluoroacetic acid. Electrochemical analyses provide support for the notion that protonation causes a dramatic anodic shift in the reduction potentials of octaphyrin 1, thereby facilitating electron transfer from halide anions (viz. I-, Br-, and, Cl-). Electron-rich molecules, such as tetrathiafulvene (TTF), phenothiazine (PTZ), and catechol, were also found to induce PCET in the case of 1. Both the oxidized and two-electron reduced forms of 1 were characterized by X-ray diffraction analyses in the solid state and in solution via spectroscopic means.
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Affiliation(s)
- Tridib Sarma
- Center for Supramolecular Chemistry & Catalysis , Shanghai University , Shanghai 200444 , China.,Department of Chemistry , The University of Texas at Austin , 105 East 24th Street, Stop A5300 , Austin , Texas 78712-1224 , United States
| | - Gakhyun Kim
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems , Yonsei University , Seoul 03722 , Korea
| | - Sajal Sen
- Department of Chemistry , The University of Texas at Austin , 105 East 24th Street, Stop A5300 , Austin , Texas 78712-1224 , United States
| | - Won-Young Cha
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems , Yonsei University , Seoul 03722 , Korea
| | - Zhiming Duan
- Center for Supramolecular Chemistry & Catalysis , Shanghai University , Shanghai 200444 , China
| | - Matthew D Moore
- Department of Chemistry , The University of Texas at Austin , 105 East 24th Street, Stop A5300 , Austin , Texas 78712-1224 , United States
| | - Vincent M Lynch
- Department of Chemistry , The University of Texas at Austin , 105 East 24th Street, Stop A5300 , Austin , Texas 78712-1224 , United States
| | - Zhan Zhang
- Center for Supramolecular Chemistry & Catalysis , Shanghai University , Shanghai 200444 , China
| | - Dongho Kim
- Department of Chemistry and Spectroscopy Laboratory for Functional π-Electronic Systems , Yonsei University , Seoul 03722 , Korea
| | - Jonathan L Sessler
- Center for Supramolecular Chemistry & Catalysis , Shanghai University , Shanghai 200444 , China.,Department of Chemistry , The University of Texas at Austin , 105 East 24th Street, Stop A5300 , Austin , Texas 78712-1224 , United States
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4
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Valiev RR, Fliegl H, Sundholm D. Bicycloaromaticity and Baird-type bicycloaromaticity of dithienothiophene-bridged [34]octaphyrins. Phys Chem Chem Phys 2018; 20:17705-17713. [PMID: 29942971 DOI: 10.1039/c8cp03112f] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aromatic properties of two recently synthesized dithienothiophene-bridged (DTT) [34]octaphyrins have been investigated by calculating magnetically induced current densities and vertical excitation energies. These intriguing molecules have been proposed to be the first synthesized neutral bicycloaromatic compounds. The triplet state of their dications was even suggested to be Baird-type bicycloaromatic rendering them very interesting as a new prototype of molecules possessing simultaneously the two rare types of aromaticity. Here, we investigate computationally the aromatic properties of the neutral as well as the singly and doubly charged DTT-bridged [34]octaphyrins. Our study provides unambiguous information about changes in the aromatic properties of the DTT-bridged [34]octaphyrins upon oxidation. The calculations identify two independent diatropic ring currents in the neutral DTT-bridged [34]octaphyrins, showing that they are indeed bicycloaromatic. The current-density flow of the two independent ring currents of the bicycloaromatic compounds are visualized and individual aromatic pathways are quantified by performing numerical integration. The calculations show that two independent diatropic ring currents can indeed be sustained by molecules consisting of two aromatic rings that share a common set of π electrons. The current density calculations on the singly charged DTT-bridged [34]octaphyrins show that they are weakly antiaromatic, which does not agree with the suggested aromatic character deduced from spectroscopical studies. The triplet state of the two DTT-bridged [34]octaphyrin cations with very similar molecular structures have unexpectedly different aromatic character. One of them is Baird-type bicycloaromatic, whereas the triplet state of the other dication has one aromatic and one nonaromatic ring, which could not be resolved from available spectroscopical data. Calculations of excitation energies reveal that a simple model cannot be employed for interpreting the electronic excitation spectra of the present molecules, because more than 20 excited states contribute to the spectra above 2.5 eV (500 nm) showing the importance of computations. The present work illustrates how detailed information about molecular aromaticity can nowadays be obtained by scrutinizing calculated current densities.
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Affiliation(s)
- Rashid R Valiev
- Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland.
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