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Toganoh M, Furuta H. Creation from Confusion and Fusion in the Porphyrin World─The Last Three Decades of N-Confused Porphyrinoid Chemistry. Chem Rev 2022; 122:8313-8437. [PMID: 35230807 DOI: 10.1021/acs.chemrev.1c00065] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Confusion is a novel concept of isomerism in porphyrin chemistry, delivering a steady stream of new chemistry since the discovery of N-confused porphyrin, a porphyrin mutant, in 1994. These days, the number of confused porphyrinoids is increasing, and confusion and associated fusion are found in various fields such as supramolecular chemistry, materials chemistry, biological chemistry, and catalysts. In this review, the birth and growth of confused porphyrinoids in the last three decades are described.
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Affiliation(s)
- Motoki Toganoh
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hiroyuki Furuta
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
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Bhyrappa P, Sarangi UK. Effect of solvent on the electronic absorption spectral properties of mixed β-octasubstituted free base tetraphenylporphyrins. J PORPHYR PHTHALOCYA 2021. [DOI: 10.1142/s1088424621500371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A near planar macrocycle containing 2,3,12,13-tetraphenylethynyl-5,10,15,20-tetrakis-(4[Formula: see text]-[Formula: see text]-butylphenyl)porphyrin, H2T(4[Formula: see text]-[Formula: see text]-Bu Ph)P(PE)4 and a series of antipodally mixed substituted nonplanar porphyrins, 2,3,5,10,12,13,15,20-octaphenyl-7,8,17,18-tetra(2[Formula: see text]-thienyl/phenylethynyl, PE)porphyrin, H2OPP(2[Formula: see text]-Th/PE)4 and 2,3,12,13-tetramethyl-7,8,17,18-tetra(2[Formula: see text]-thienyl/PE)-5,10,15,20-tetraphenylporphyrin, H2TPP(CH[Formula: see text](2[Formula: see text]-Th/PE)4were examined by electronic absorption spectroscopy in twenty different solvents. The presence of push-pull substituents at the antipodal [Formula: see text]-pyrrole positions of the nonplanar macrocycle induces varying degrees of orthogonal dipole moments to the porphyrin ring. The influence of different solvents on the degree of nonplanarity and electronic nature of the macrocycle on their electronic absorption spectral properties were examined. Generally, free base porphyrins showed dramatic solvent dependent absorption spectral band shifts and follow the order: H2OPP(PE)4 > H2OPP(2[Formula: see text]-Th)[Formula: see text] H2TPP(CH[Formula: see text](2[Formula: see text]-Th)4 >[Formula: see text]H2TPP(CH[Formula: see text](PE)4 > H2T(4[Formula: see text]-[Formula: see text]Bu Ph)P(PE)4. Absorption spectral data in different solvents was analyzed using selected solvatochromic parameters, ([Formula: see text] – 1)/(2[Formula: see text] + 1), [Formula: see text] (30),[Formula: see text], and [Formula: see text]*. The enhanced red-shift of the absorption bands of the mixed substituted porphyrins in polar solvents was influenced by solvent-core (porphyrin) interaction and is reflected from the 1H NMR chemical shift of the core imino-hydrogens in polar solvents relative that observed in less polar solvents. The magnitude of the difference in chemical shift ([Formula: see text], ppm) of imino-hydrogens in DMSO-d6 relative to that in CDCl3 follow the order: H2TPP(CH[Formula: see text](2[Formula: see text]-Th)4 (1.37 ppm) > H2OPP(PE)4 (1.17 ppm) > H2TPP(CH[Formula: see text](PE)4 (0.57 ppm). The large red-shift in B and Q bands in polar solvents relative to apolar (or less polar) solvents has been possible due to the combined effect of the electronic nature of the macrocycle, its nonplanarity, and solvent-porphyrin core interactions.
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Affiliation(s)
- P. Bhyrappa
- Department of Chemistry, Indian Institute of Technology, Madras. Chennai 600 036, India
| | - U. K. Sarangi
- Department of Chemistry, Indian Institute of Technology, Madras. Chennai 600 036, India
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Ishizuka T, Sakashita R, Iwanaga O, Morimoto T, Mori S, Ishida M, Toganoh M, Takegoshi K, Osuka A, Furuta H. NH Tautomerism of N-Confused Porphyrin: Solvent/Substituent Effects and Isomerization Mechanism. J Phys Chem A 2020; 124:5756-5769. [PMID: 32559101 DOI: 10.1021/acs.jpca.0c04779] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effects of substituents and solvents on the NH tautomerism of N-confused porphyrin (2) were investigated. The structures, electronic states, and aromaticity of NH tautomers (2-2H and 2-3H) were studied by absorption and nuclear magnetic resonance (1H, 13C, and 15N) spectroscopies, single-crystal X-ray diffraction analysis, and theoretical calculations. The relative stability of the tautomers is highly affected by solvents, with the 3H-type tautomer being more stable in nonpolar solvents, while the 2H-type tautomer being highly stabilized in polar solvents with high donor numbers such as N,N-dimethylformamide (DMF), pyridine, and acetone. Electron-withdrawing groups on the meso-aryl substituents as well as the methyl group at the ortho position also stabilize the 2H-type tautomer. Kinetically, the tautomerism rate is significantly influenced by solvent and concentration, and a particularly large activation entropy (ΔS⧧) is obtained in pyridine. The first-order deuterium isotope effect on the reaction rates of NH tautomerism (kH/kD) is determined to be 2.4 at 298 K. On the basis of kinetic data, the mechanism of isomerization is identified as an intramolecular process, including the rotation of the confused pyrrole in pyridine/chloroform and DMF/chloroform mixed solvent systems, and as a pyridine-mediated process in pyridine alone.
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Affiliation(s)
- Tomoya Ishizuka
- Department of Chemistry and Biochemistry, Graduate School of Engineering and Center for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan.,Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Japan.,Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Ryuichi Sakashita
- Department of Chemistry and Biochemistry, Graduate School of Engineering and Center for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan
| | - Osamu Iwanaga
- Department of Chemistry and Biochemistry, Graduate School of Engineering and Center for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan
| | - Tatsuki Morimoto
- Department of Chemistry and Biochemistry, Graduate School of Engineering and Center for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan.,Department of Applied Chemistry, School of Engineering, Tokyo University of Technology, Hachioji 192-0982, Japan
| | - Shigeki Mori
- Advanced Research Support Center, Ehime University, Matsuyama 790-8577, Japan
| | - Masatoshi Ishida
- Department of Chemistry and Biochemistry, Graduate School of Engineering and Center for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan
| | - Motoki Toganoh
- Department of Chemistry and Biochemistry, Graduate School of Engineering and Center for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan
| | - Kiyonori Takegoshi
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Hiroyuki Furuta
- Department of Chemistry and Biochemistry, Graduate School of Engineering and Center for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan
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Alemán EA, Joseph J, Modarelli DA. Solvent Effects on the UV–Vis Absorption Properties and Tautomerism of N-Confused Tetraphenylporphyrin. J Org Chem 2015; 80:11031-8. [DOI: 10.1021/acs.joc.5b02244] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elvin A. Alemán
- Department
of Chemistry, California State University Stanislaus, One University
Circle, Turlock, California 95382, United States
| | - Jojo Joseph
- Department
of Chemistry and The Center for Laser and Optical Spectroscopy, Knight
Chemical Laboratory, The University of Akron, Akron, Ohio 44325-3601, United States
| | - David A. Modarelli
- Department
of Chemistry and The Center for Laser and Optical Spectroscopy, Knight
Chemical Laboratory, The University of Akron, Akron, Ohio 44325-3601, United States
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