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Sanfui S, Roychowdhury A, Usman M, Garribba E, Gómez-García CJ, Rath SP. Metal vs Ligand Oxidation: Coexistence of Both Metal-Centered and Ligand-Centered Oxidized Species. Inorg Chem 2024; 63:5423-5431. [PMID: 38483819 DOI: 10.1021/acs.inorgchem.3c04043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
A series of two-electron-oxidized cobalt porphyrin dimers have been synthesized upon controlled oxidations using halogens. Rather unexpectedly, X-ray structures of two of these complexes contain two structurally different low-spin molecules in the same asymmetric unit of their unit cells: one is the metal-centered oxidized diamagnetic entity of the type CoIII(por), while the other one is the ligand-centered oxidized paramagnetic entity of the type CoII(por•+). Spectroscopic, magnetic, and DFT investigations confirmed the coexistence of the two very different electronic structures both in the solid and solution phases and also revealed a ferromagnetic spin coupling between Co(II) and porphyrin π-cation radicals and a weak antiferromagnetic coupling between the π-cation radicals of two macrocycles via the bridge in the paramagnetic complex.
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Affiliation(s)
- Sarnali Sanfui
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Arya Roychowdhury
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Mohammad Usman
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Eugenio Garribba
- Dipartimento di Medicina, Chirurgia e Farmacia, Viale San Pietro, Università di Sassari, Sassari I-07100, Italy
| | - Carlos J Gómez-García
- Departamento de Química Inorgánica, Universidad de Valencia, C/Dr. Moliner 50, Burjasot, Valencia 46100, Spain
| | - Sankar Prasad Rath
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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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: 18] [Impact Index Per Article: 9.0] [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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3
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Sanfui S, Usman M, Sarkar S, Pramanik S, Garribba E, Rath SP. Highly Oxidized Cobalt Porphyrin Dimer: Control of Spin Coupling via a Bridge. Inorg Chem 2022; 61:8419-8430. [PMID: 35613476 DOI: 10.1021/acs.inorgchem.1c03807] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A cobalt porphyrin dimer is constructed in which two Co(II)porphyrins are connected covalently through a redox-active diethylpyrrole moiety via a flexible but "nonconjugated" methylene bridge. Upon oxidation with even a mild oxidant such as iodine, each cobalt(II) center and porphyrin ring undergo 1e- oxidation, leading to the formation of a 4e--oxidized cobalt(III)porphyrin dication diradical complex. Other oxidants such as Cl2 and Br2 also produce similar results. To stabilize such highly oxidized dication diradicals, the "nonconjugated" methylene spacer undergoes a facile and spontaneous oxidation to form a methine group with a drastic structural change, thereby making the bridge fully π-conjugated and enabling through-bond communication. This results in a strong spin coupling between two π-cation radicals which stabilizes the singlet state. The experimental observations are also strongly supported by extensive density functional theory calculations. The present study highlights the crucial role played by the nature of the bridge in the long-range electronic communication.
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Affiliation(s)
- Sarnali Sanfui
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Mohammad Usman
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Sabyasachi Sarkar
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Subhadip Pramanik
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Eugenio Garribba
- Dipartimento di Scienze Mediche, Chirurgiche e Sperimentali, Università di Sassari, Viale San Pietro, Sassari I-07100, Italy
| | - Sankar Prasad Rath
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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Chen CC, Wu YW, Nakamura M, Cheng RJ, Tseng TH, Chen PPY. Assessment of the intramolecular magnetic interactions in the highly saddled iron(iii) porphyrin π-radical cations: the change from planar to saddle conformations. Dalton Trans 2019; 48:13820-13833. [PMID: 31482912 DOI: 10.1039/c9dt02714a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The intramolecular magnetic interactions in one-electron oxidized iron(iii) porphyrin π-radical cations, [Fe(OETPP˙)Cl][SbCl6] (1), [Fe(OMTPP˙)Cl][SbCl6] (2) and [Fe(TPP˙)Cl][SbCl6] (3), have been compared by means of X-ray crystallography, SQUID magnetometry, cyclic voltammetry, UV-Vis spectroelectrochemical analysis, NMR spectroscopy analysis and unrestricted DFT calculations. Unlike a generally recognized antiferromagnetic coupling dxy↑dxz↑dyz↑dz2↑dx2-y2↑P˙+(a2u)↓ (S = 2) state via a weak bonding interaction as in (3), we have disclosed that a strong bonding interaction among iron dx2-y2 and porphyrin a2u orbitals forms in (1) into a highly delocalized Ψπ = [P˙+(a2u) + FeIII(dx2-y2, dz2)] orbital that is able to accommodate two spin-paired electrons to form the Ψπ2dxy1dxz1dyz1, dz21 (S = 2) ground state. Concurrently, the spin polarization effect is exerted on the paired spins in the Ψπ orbital by magnetic induction from the remaining unpaired electrons in the iron d orbitals. The interpretation mentioned above is further verified by the diamagnetic nature of the saddled copper(ii) porphyrin π-cation radical, CuII(OETPP˙)(ClO4) (S = 0), where the strong bonding interaction leads to the Ψπ2dxy2dxz2dyz2dz22 (S = 0) ground state but no spin polarization exists. Thus, the magnetic nature of the iron(iii) porphyrin π-radical cation is tuneable by saddling the ring planarity.
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Affiliation(s)
- Ching-Chin Chen
- Department of Chemistry, National Chung Hsing University, 145 Xingda Rd., South Dist., Taichung City 402, Taiwan.
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Mondal B, Saha S, Borah D, Mazumdar R, Mondal B. Nitric Oxide Dioxygenase Activity of a Nitrosyl Complex of Cobalt(II) Porphyrinate in the Presence of Hydrogen Peroxide via Putative Peroxynitrite Intermediate. Inorg Chem 2019; 58:1234-1240. [PMID: 30623661 DOI: 10.1021/acs.inorgchem.8b02722] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The reaction of a cobalt porphyrin complex, [(F8TPP)Co], 1 {F8TPP = 5,10,15,20- tetrakis(2,6-difluorophenyl)porphyrinate dianion} in dichloromethane with nitric oxide (NO) led to the nitrosyl complex, [(F8TPP)Co(NO)], 2. Spectroscopic studies and structural characterization revealed it as a bent nitrosyl of {CoNO}8 description. It was stable in the presence of dioxygen. However, it reacts with H2O2 in acetonitrile (or THF) solution at -40 °C (or -80 °C) to result in the corresponding Co(III)-nitrate complex, [(F8TPP)Co(NO3)], 3. The reaction presumably proceeds via the formation of a Co-peroxynitrite intermediate. X-Band electron paramagnetic resonance and electrospray ionization-mass spectroscopic studies suggest the intermediate formation of the [(porphyrin)Co(III)-O•] radical, which in turn supports the generation of the corresponding Co(IV)-oxo species during the reaction. This is in accord with the homolytic cleavage of the O-O bond in heme-peroxynitrite proposed in the nitric oxide dioxygenases activity. In addition, the characteristic peroxynitrite-induced phenol ring reaction was also observed.
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Affiliation(s)
- Baishakhi Mondal
- Department of Chemistry , Indian Institute of Technology Guwahati , North Guwahati , Assam 781039 , India
| | - Soumen Saha
- Department of Chemistry , Indian Institute of Technology Guwahati , North Guwahati , Assam 781039 , India
| | - Dibyajyoti Borah
- Department of Chemistry , Indian Institute of Technology Guwahati , North Guwahati , Assam 781039 , India
| | - Rakesh Mazumdar
- Department of Chemistry , Indian Institute of Technology Guwahati , North Guwahati , Assam 781039 , India
| | - Biplab Mondal
- Department of Chemistry , Indian Institute of Technology Guwahati , North Guwahati , Assam 781039 , India
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Roucan M, Kielmann M, Connon SJ, Bernhard SSR, Senge MO. Conformational control of nonplanar free base porphyrins: towards bifunctional catalysts of tunable basicity. Chem Commun (Camb) 2018; 54:26-29. [DOI: 10.1039/c7cc08099a] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
No metal needed: nonplanar free base porphyrins act as bifunctional organocatalysts revealing a new mode of action for porphyrins.
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Affiliation(s)
- M. Roucan
- School of Chemistry
- SFI Tetrapyrrole Laboratory
- Trinity College Dublin
- The University of Dublin
- Trinity Biomedical Sciences Institute
| | - M. Kielmann
- School of Chemistry
- SFI Tetrapyrrole Laboratory
- Trinity College Dublin
- The University of Dublin
- Trinity Biomedical Sciences Institute
| | - S. J. Connon
- School of Chemistry
- Trinity College Dublin
- The University of Dublin
- Trinity Biomedical Sciences Institute
- Dublin 2
| | - S. S. R. Bernhard
- School of Chemistry
- SFI Tetrapyrrole Laboratory
- Trinity College Dublin
- The University of Dublin
- Trinity Biomedical Sciences Institute
| | - M. O. Senge
- School of Chemistry
- SFI Tetrapyrrole Laboratory
- Trinity College Dublin
- The University of Dublin
- Trinity Biomedical Sciences Institute
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Saha S, Gogoi K, Mondal B, Ghosh S, Deka H, Mondal B. Reaction of a Nitrosyl Complex of Cobalt Porphyrin with Hydrogen Peroxide: Putative Formation of Peroxynitrite Intermediate. Inorg Chem 2017. [DOI: 10.1021/acs.inorgchem.7b00491] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Soumen Saha
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
| | - Kuldeep Gogoi
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
| | - Baishakhi Mondal
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
| | - Somnath Ghosh
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
| | - Hemanta Deka
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
| | - Biplab Mondal
- Department
of Chemistry, Indian Institute of Technology Guwahati, North
Guwahati, Assam 781039, India
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Dey S, Sil D, Rath SP. A Highly Oxidized Cobalt Porphyrin Dimer: Spin Coupling and Stabilization of the Four-Electron Oxidation Product. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201509430] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Soumyajit Dey
- Department of Chemistry; Indian Institute of Technology Kanpur; Kanpur- 208016 India
| | - Debangsu Sil
- Department of Chemistry; Indian Institute of Technology Kanpur; Kanpur- 208016 India
| | - Sankar Prasad Rath
- Department of Chemistry; Indian Institute of Technology Kanpur; Kanpur- 208016 India
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9
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Dey S, Sil D, Rath SP. A Highly Oxidized Cobalt Porphyrin Dimer: Spin Coupling and Stabilization of the Four-Electron Oxidation Product. Angew Chem Int Ed Engl 2015; 55:996-1000. [DOI: 10.1002/anie.201509430] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Soumyajit Dey
- Department of Chemistry; Indian Institute of Technology Kanpur; Kanpur- 208016 India
| | - Debangsu Sil
- Department of Chemistry; Indian Institute of Technology Kanpur; Kanpur- 208016 India
| | - Sankar Prasad Rath
- Department of Chemistry; Indian Institute of Technology Kanpur; Kanpur- 208016 India
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