1
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Kira S, Miyamae T, Yoshida K, Kanzaki Y, Sugisaki K, Shiomi D, Sato K, Takui T, Suzuki S, Kozaki M, Okada K. Aurophilic Interactions in Multi-Radical Species: Electronic-Spin and Redox Properties of Bis- and Tris-[(Nitronyl Nitroxide)-Gold(I)] Complexes with Phosphine-Ligand Scaffolds. Chemistry 2021; 27:11450-11457. [PMID: 34038598 DOI: 10.1002/chem.202101483] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Indexed: 01/23/2023]
Abstract
Multinuclear AuI complexes with two or three nitronyl nitroxide-2-ide radical anion and phosphine-ligand scaffolds, (NN-Au)2 -1 o, (NN-Au)2 -1 m, and (NN-Au)2 -1 p, have been synthesized to investigate the influence of AuI -AuI (aurophilic) interactions on the properties of multispin molecular systems. The desired complexes were successfully prepared in moderate yields in a one-pot synthesis from the corresponding phosphine ligand, AuI source, parent NN, and sodium hydroxide. Among the prepared complexes, (NN-Au)2 -1 o, in which an aurophilic interaction was clearly observed by crystal structure analysis, showed characteristic spin-spin interactions, electrochemical properties, and solvatochromic behavior. The results from theoretical calculations also suggested that the differences in properties between complex (NN-Au)2 -1 o and the other complexes are due to intramolecular aurophilic interactions.
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Affiliation(s)
- Sayaka Kira
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Takayuki Miyamae
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Kohei Yoshida
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Yuki Kanzaki
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Kenji Sugisaki
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Daisuke Shiomi
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Kazunobu Sato
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Takeji Takui
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Shuichi Suzuki
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Masatoshi Kozaki
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan.,Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
| | - Keiji Okada
- Graduate School of Science, Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan.,Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University Sumiyoshi-ku, Osaka, Osaka 558-8585, Japan
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2
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Wang K, Liu P, Zhang F, Xu L, Zhou M, Nakai A, Kato K, Furukawa K, Tanaka T, Osuka A, Song J. A Robust Porphyrin-Stabilized Triplet Carbon Diradical. Angew Chem Int Ed Engl 2021; 60:7002-7006. [PMID: 33393192 DOI: 10.1002/anie.202015356] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/25/2020] [Indexed: 11/06/2022]
Abstract
The synthesis of robust high-spin carbon radicals is an important topic in organic chemistry. Toward this end, several porphyrin-stabilized radicals have been systematically explored. A singly naphthalene-fused porphyrin radical was synthesized by a reaction sequence consisting of a Suzuki-Miyaura coupling of β-borylated porphyrin with 2-bromobenzaldehyde, addition of mesityl Grignard reagent, intramolecular Friedel-Crafts alkylation, and final oxidation with DDQ or tBuOK/O2 . This strategy was also used to synthesize doubly naphthalene-fused porphyrins and syn- and anti-fused-anthracene-bridged porphyrin dimers. While singly naphthalene-fused porphyrin radical has been shown to be a stable monoradical, doubly naphthalene-fused porphyrins and anti-fused-anthracene-bridged porphyrin dimers have been shown to be closed-shell molecules. Finally, the syn-dimer was characterized as a surprisingly stable radical (t1/2 =28 days under ambient air and at 80 °C) that is storable for more than several months, despite its high-spin triplet ground-state carbon diradical.
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Affiliation(s)
- Kaisheng Wang
- College of Chemistry and Chemical Engineering, Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province, Hunan Normal University, Changsha, 410081, China
| | - Pingting Liu
- College of Chemistry and Chemical Engineering, Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province, Hunan Normal University, Changsha, 410081, China
| | - Fenni Zhang
- College of Chemistry and Chemical Engineering, Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province, Hunan Normal University, Changsha, 410081, China
| | - Ling Xu
- College of Chemistry and Chemical Engineering, Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province, Hunan Normal University, Changsha, 410081, China
| | - Mingbo Zhou
- College of Chemistry and Chemical Engineering, Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province, Hunan Normal University, Changsha, 410081, China
| | - Akito Nakai
- Department of Chemistry, Graduate School of Science Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Kenichi Kato
- Department of Chemistry, Graduate School of Science Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Ko Furukawa
- Center for Instrumental Analysis, Niigata University, Nishi-ku, Niigata, 950-2181, Japan
| | - Takayuki Tanaka
- Department of Chemistry, Graduate School of Science Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Atsuhiro Osuka
- College of Chemistry and Chemical Engineering, Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province, Hunan Normal University, Changsha, 410081, China
| | - Jianxin Song
- College of Chemistry and Chemical Engineering, Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province, Hunan Normal University, Changsha, 410081, China
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3
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Wang K, Liu P, Zhang F, Xu L, Zhou M, Nakai A, Kato K, Furukawa K, Tanaka T, Osuka A, Song J. A Robust Porphyrin‐Stabilized Triplet Carbon Diradical. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202015356] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Kaisheng Wang
- College of Chemistry and Chemical Engineering Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province Hunan Normal University Changsha 410081 China
| | - Pingting Liu
- College of Chemistry and Chemical Engineering Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province Hunan Normal University Changsha 410081 China
| | - Fenni Zhang
- College of Chemistry and Chemical Engineering Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province Hunan Normal University Changsha 410081 China
| | - Ling Xu
- College of Chemistry and Chemical Engineering Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province Hunan Normal University Changsha 410081 China
| | - Mingbo Zhou
- College of Chemistry and Chemical Engineering Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province Hunan Normal University Changsha 410081 China
| | - Akito Nakai
- Department of Chemistry Graduate School of Science Kyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Kenichi Kato
- Department of Chemistry Graduate School of Science Kyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Ko Furukawa
- Center for Instrumental Analysis Niigata University Nishi-ku Niigata 950-2181 Japan
| | - Takayuki Tanaka
- Department of Chemistry Graduate School of Science Kyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Atsuhiro Osuka
- College of Chemistry and Chemical Engineering Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province Hunan Normal University Changsha 410081 China
| | - Jianxin Song
- College of Chemistry and Chemical Engineering Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) Key Laboratory of the Assembly and Application of Organic Functional molecules of Hunan Province Hunan Normal University Changsha 410081 China
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4
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Sigmund LM, Ebner F, Jöst C, Spengler J, Gönnheimer N, Hartmann D, Greb L. An Air-Stable, Neutral Phenothiazinyl Radical with Substantial Radical Stabilization Energy. Chemistry 2020; 26:3152-3156. [PMID: 31944465 PMCID: PMC7079145 DOI: 10.1002/chem.201905238] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Indexed: 01/12/2023]
Abstract
The vital effect of radical states on the pharmacological activity of phenothiazine-based drugs has long been speculated. Whereas cationic radicals of N-substituted phenothiazines show high stability, the respective neutral radicals of N-unsubstituted phenothiazines have never been isolated. Herein, the 1,9-diamino-3,7-di-tert-butyl-N1 ,N9 -bis(2,6-diisopropylphenyl)-10H-phenothiazin-10-yl radical (SQH2 . ) is described as the first air-stable, neutral phenothiazinyl free radical. The crystalline dark-blue species is characterized by means of EPR and UV/Vis/near-IR spectroscopy, as well as cyclic voltammetry, spectro-electrochemical analysis, single-crystal XRD, and computational studies. The SQH2 . radical stands out from other aminyl radicals by an impressive radical stabilization energy and its parent amine has one of the weakest N-H bond dissociation energies ever determined. In addition to serving as open-shell reference in medicinal chemistry, its tridentate binding pocket or hydrogen-bond-donor ability might enable manifold uses as a redox-active ligand or proton-coupled electron-transfer reagent.
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Affiliation(s)
- Lukas M. Sigmund
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Fabian Ebner
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Christoph Jöst
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Jonas Spengler
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Nils Gönnheimer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Deborah Hartmann
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Lutz Greb
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
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5
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Nagata A, Hiraoka S, Suzuki S, Kozaki M, Shiomi D, Sato K, Takui T, Tanaka R, Okada K. Redox‐Induced Modulation of Exchange Interaction in a High‐Spin Ground‐State Diradical/Triradical System. Chemistry 2020; 26:3166-3172. [DOI: 10.1002/chem.201905465] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Atsuki Nagata
- Graduate School of ScienceOsaka City University Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
| | - Shinsuke Hiraoka
- Graduate School of ScienceOsaka City University Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
| | - Shuichi Suzuki
- Graduate School of ScienceOsaka City University Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
- Graduate School of Engineering ScienceOsaka University Toyonaka Osaka 560-8531 Japan
| | - Masatoshi Kozaki
- Graduate School of ScienceOsaka City University Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
- Osaka City UniversityAdvanced Research Institute for, Natural Science and Technology (OCARINA) Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
| | - Daisuke Shiomi
- Graduate School of ScienceOsaka City University Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
| | - Kazunobu Sato
- Graduate School of ScienceOsaka City University Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
| | - Takeji Takui
- Graduate School of ScienceOsaka City University Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
| | - Rika Tanaka
- X-ray Crystal Analysis LaboratoryGraduate School of Engineering, Osaka City University Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
| | - Keiji Okada
- Graduate School of ScienceOsaka City University Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
- Osaka City UniversityAdvanced Research Institute for, Natural Science and Technology (OCARINA) Sumiyoshi-ku, Osaka Osaka 558-8585 Japan
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6
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Yamamoto T, Kato K, Shimizu D, Tanaka T, Osuka A. Phenylene-bridged Porphyrin meso-Oxy Radical Dimers. Chem Asian J 2019; 14:4031-4034. [PMID: 31419053 DOI: 10.1002/asia.201901033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Indexed: 02/05/2023]
Abstract
Stable meta- and para-phenylene bridged porphyrin meso-oxy radical dimers and their NiII and ZnII complexes were synthesized. All the dimers exhibited optical and electrochemical properties similar to the corresponding porphyrin meso-oxy radical monomers, indicating small electronic interaction between the two spins. Intramolecular spin-spin interaction through the π-spacer was determined to be J/kB =-15.9 K for m-phenylene bridged ZnII porphyrin dimer. The observed weak antiferromagnetic interaction has been attributed to less effective conjugation between the porphyrin radical and linking π-spacer due to large dihedral angle. In the case of ZnII complexes, both para- and meta-phenylene bridged dimers formed 1D-chain in solutions and in the solid states through Zn-O coordination.
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Affiliation(s)
- Takayuki Yamamoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Kenichi Kato
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Daiki Shimizu
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Takayuki Tanaka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
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7
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Kato K, Osuka A. meta
‐ and
para
‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals. Angew Chem Int Ed Engl 2019; 58:8546-8550. [DOI: 10.1002/anie.201901939] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/07/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Kenichi Kato
- Department of ChemistryGraduate School of ScienceKyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Atsuhiro Osuka
- Department of ChemistryGraduate School of ScienceKyoto University Sakyo-ku Kyoto 606-8502 Japan
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8
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Kato K, Osuka A. meta
‐ and
para
‐Phenylenediamine‐Fused Porphyrin Dimers: Synthesis and Magnetic Interactions of Their Dication Diradicals. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201901939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kenichi Kato
- Department of ChemistryGraduate School of ScienceKyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Atsuhiro Osuka
- Department of ChemistryGraduate School of ScienceKyoto University Sakyo-ku Kyoto 606-8502 Japan
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9
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Shimizu D, Ide Y, Ikeue T, Osuka A. Coordination‐Induced Spin‐State Switching of an Aminyl‐Radical‐Bridged Nickel(II) Porphyrin Dimer between Doublet and Sextet States. Angew Chem Int Ed Engl 2019; 58:5023-5027. [PMID: 30761702 DOI: 10.1002/anie.201900792] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Daiki Shimizu
- Department of ChemistryGraduate School of ScienceKyoto University, Sakyo-ku Kyoto 606-8502 Japan
| | - Yuki Ide
- Interdisciplinary Graduate School of Science and EngineeringShimane University, Nishikawatsu-Cho Matsue 690-8504 Japan
| | - Takahisa Ikeue
- Interdisciplinary Graduate School of Science and EngineeringShimane University, Nishikawatsu-Cho Matsue 690-8504 Japan
| | - Atsuhiro Osuka
- Department of ChemistryGraduate School of ScienceKyoto University, Sakyo-ku Kyoto 606-8502 Japan
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10
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Shimizu D, Ide Y, Ikeue T, Osuka A. Coordination‐Induced Spin‐State Switching of an Aminyl‐Radical‐Bridged Nickel(II) Porphyrin Dimer between Doublet and Sextet States. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201900792] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Daiki Shimizu
- Department of ChemistryGraduate School of ScienceKyoto University, Sakyo-ku Kyoto 606-8502 Japan
| | - Yuki Ide
- Interdisciplinary Graduate School of Science and EngineeringShimane University, Nishikawatsu-Cho Matsue 690-8504 Japan
| | - Takahisa Ikeue
- Interdisciplinary Graduate School of Science and EngineeringShimane University, Nishikawatsu-Cho Matsue 690-8504 Japan
| | - Atsuhiro Osuka
- Department of ChemistryGraduate School of ScienceKyoto University, Sakyo-ku Kyoto 606-8502 Japan
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11
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Adinarayana B, Shimizu D, Osuka A. Stable (BIII
-Subporphyrin-5-yl)dicyanomethyl Radicals. Chemistry 2019; 25:1706-1710. [DOI: 10.1002/chem.201805601] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Indexed: 11/12/2022]
Affiliation(s)
- Bellamkonda Adinarayana
- Department of Chemistry; Graduate School of Science; Kyoto University; Sakyo-ku Kyoto 606-8502 Japan
| | - Daiki Shimizu
- Department of Chemistry; Graduate School of Science; Kyoto University; Sakyo-ku Kyoto 606-8502 Japan
| | - Atsuhiro Osuka
- Department of Chemistry; Graduate School of Science; Kyoto University; Sakyo-ku Kyoto 606-8502 Japan
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12
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Fujimoto K, Shimizu D, Osuka A. Porphyrin‐Stabilized Nitrenium Dication. Chemistry 2018; 25:521-525. [DOI: 10.1002/chem.201805491] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Keisuke Fujimoto
- Department of ChemistryGraduate School of ScienceKyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Daiki Shimizu
- Department of ChemistryGraduate School of ScienceKyoto University Sakyo-ku Kyoto 606-8502 Japan
| | - Atsuhiro Osuka
- Department of ChemistryGraduate School of ScienceKyoto University Sakyo-ku Kyoto 606-8502 Japan
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13
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Shimizu D, Fujimoto K, Osuka A. Stable Diporphyrinylaminyl Radical and Nitrenium Ion. Angew Chem Int Ed Engl 2018; 57:9434-9438. [PMID: 29882340 DOI: 10.1002/anie.201805385] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Indexed: 11/10/2022]
Abstract
Nitrenium ions, isoelectronic nitrogen counterparts of carbenes, are important intermediates in various biological and chemical processes. Herein we describe the first synthesis and characterization of a stable nitrenium ion without resonance stabilization by adjoining amino groups. Namely, a stable salt of a diporphyrinylnitrenium ion was synthesized by stepwise oxidation of the corresponding diporphyrinylamine through a stable aminyl radical. The nitrenium ion exhibits characteristic features such as a singlet ground state, enhanced double-bond character of the central C-N bonds, no reactivity toward water and methanol, and negative solvatochromic behavior.
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Affiliation(s)
- Daiki Shimizu
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Keisuke Fujimoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
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14
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Shimizu D, Fujimoto K, Osuka A. Stable Diporphyrinylaminyl Radical and Nitrenium Ion. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201805385] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Daiki Shimizu
- Department of Chemistry; Graduate School of Science; Kyoto University; Sakyo-ku Kyoto 606-8502 Japan
| | - Keisuke Fujimoto
- Department of Chemistry; Graduate School of Science; Kyoto University; Sakyo-ku Kyoto 606-8502 Japan
| | - Atsuhiro Osuka
- Department of Chemistry; Graduate School of Science; Kyoto University; Sakyo-ku Kyoto 606-8502 Japan
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15
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Kato K, Furukawa K, Osuka A. A Stable Trimethylenemethane Triplet Diradical Based on a Trimeric Porphyrin Fused π-System. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804644] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Kenichi Kato
- Department of Chemistry; Graduate School of Science; Kyoto University; Sakyo-ku Kyoto 606-8502 Japan
| | - Ko Furukawa
- Center for Instrumental Analysis; Niigata University; Nishi-ku Niigata 950-2181 Japan
| | - Atsuhiro Osuka
- Department of Chemistry; Graduate School of Science; Kyoto University; Sakyo-ku Kyoto 606-8502 Japan
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16
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Kato K, Furukawa K, Osuka A. A Stable Trimethylenemethane Triplet Diradical Based on a Trimeric Porphyrin Fused π-System. Angew Chem Int Ed Engl 2018; 57:9491-9494. [PMID: 29858542 DOI: 10.1002/anie.201804644] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Indexed: 11/08/2022]
Abstract
Trimethylenemethane (TMM) diradical is the simplest non-Kekulé non-disjoint molecule with the triplet ground state (ΔEST =+16.1 kcal mol-1 ) and is extremely reactive. It is a challenge to design and synthesize a stable TMM diradical with key properties, such as actual aliphatic TMM diradical centers and the triplet ground state with a large positive ΔEST value, since such species provide detailed information on the electronic structure of TMM diradical. Herein we report a TMM derivative, in which the TMM segment is fused with three NiII meso-triarylporphyrins, that satisfies the above criteria. The diradical shows delocalized spin density on the propeller-like porphyrin π-network and the triplet ground state owing to the strong ferromagnetic interaction. Despite the apparent TMM structure, the diradical can be handled under ambient conditions and can be stored for months in the solid state, thus allowing its X-ray diffraction structural analysis.
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Affiliation(s)
- Kenichi Kato
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku Kyoto, 606-8502, Japan
| | - Ko Furukawa
- Center for Instrumental Analysis, Niigata University, Nishi-ku, Niigata, 950-2181, Japan
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku Kyoto, 606-8502, Japan
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17
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Fujimoto K, Osuka A. A 1,5-Naphthyridine-Fused Porphyrin Dimer: Intense NIR Absorption and Facile Redox Interconversion with Its Reduced Congener. Chemistry 2018. [PMID: 29536577 DOI: 10.1002/chem.201800854] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
PtII -catalyzed cyclization of β-to-β ethynylene-bridged meso-amino NiII porphyrin dimer 4 followed by oxidation with PbO2 afforded 1,5-naphthyridine-fused porphyrin dimer 5 in good yield. This dimer possesses a redox-active 1,4-diazabutadiene linkage that is interconvertible with its reduced 1,2-diaminoethene linkage upon treatments with NaBH4 or PbO2 . The dimer 5 exhibits an intense NIR absorption and a narrow HOMO-LUMO gap with a remarkably low reduction potential mainly due to effective bonding interactions in the LUMO through the 1,4-diazabutadiene linkage. In contrast, the reduced dimer 7 is fairly electron-rich with high HOMO energy and shows a relatively large HOMO-LUMO gap compared to that of 5.
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Affiliation(s)
- Keisuke Fujimoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku Kyoto, 606-8502, Japan
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku Kyoto, 606-8502, Japan
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