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Kaul N, Asempa E, Valdez-Moreira JA, Smith JM, Jakubikova E, Hammarström L. Enter Mn IV-NHC: A Dark Photooxidant with a Long-Lived Charge-Transfer Excited State. J Am Chem Soc 2024. [PMID: 39106331 DOI: 10.1021/jacs.4c08588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2024]
Abstract
Detailed photophysical investigation of a Mn(IV)-carbene complex has revealed that excitation into its lowest-energy absorption band (∼500 nm) results in the formation of an energetic ligand-to-metal charge-transfer (LMCT) state with a lifetime of 15 ns. To the best of our knowledge, this is the longest lifetime reported for charge-transfer states of first-row-based transition metal complexes in solution, barring those based on Cu, with a d10 configuration. A so-called superoxidant, Mn(IV)-carbene exhibits an excited state potential typically only harnessed via excited states of reactive organic radical species. Furthermore, the long-lived excited state in this case is found to be a dark doublet, with its transition to the quartet ground state being spin-forbidden, a contrast to most first-row literature examples, and a possible cause of the long lifetime. Showcasing excited state properties which in some cases exceed those of complexes based on precious metals, these findings not only advance the library of earth-abundant photosensitizers but also shed general insight into the photophysics of d3 and related Mn complexes.
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Affiliation(s)
- Nidhi Kaul
- Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
| | - Eyram Asempa
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Juan A Valdez-Moreira
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Jeremy M Smith
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Leif Hammarström
- Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
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Kumar R, Prakash V, Sankar M. Synthesis of Vanadyl Complexes of N-Confused Porphyrins and Their Bromoperoxidase-like Catalytic Activity. Inorg Chem 2024; 63:12506-12515. [PMID: 38912934 DOI: 10.1021/acs.inorgchem.4c01222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
Two new vanadyl complexes of N-confused porphyrins (NCPs), [VONCTPP] (V-1) and [VONCP(OMe)8] (V-2), have been synthesized for the first time and investigated as a catalyst for the oxidative bromination reaction of phenol and its derivatives. This article further delineates crystal structures, photophysical, and redox properties of both the vanadyl complexes. Complexes V-1 and V-2 exhibited a significant red shift in their absorption spectra compared with their respective free bases. The single-crystal structure of V-1 revealed that the complex is in the 2H tautomeric form, while EPR studies revealed the +4 oxidation state of vanadium metal having an axial compression with dxy1 configuration. Catalytic potential for bromoperoxidases-like activity has been explored for both complexes V-1 and V-2 for the first time in NCP chemistry with excellent TOF values (4.7-6.3 s-1 for V-1 and 7.3-8.7 s-1 for V-2) using KBr as a source of bromine and H2O2 as a green oxidant in aqueous acidic medium at 298 K. Notably, both catalysts show excellent recyclability over five cycles. The vanadyl-metalated NCPs exhibit excellent stability in the air.
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Affiliation(s)
- Rajesh Kumar
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India
| | - Ved Prakash
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India
| | - Muniappan Sankar
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India
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Ni JY, Cong SZ, Ning L, Wang M, Shen HM, She YB. Binary catalytic systems constructed by porphyrin cobalts(II) with confining nano-region and Zn(OAc)2 for oxygenation of cycloalkanes with O2 in relay mode. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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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: 34] [Impact Index Per Article: 17.0] [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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Peng SH, Wang LL, Cai SS, Xiao HQ, Zhao XT, Wang H, Liu HY. UV, FL and IR spectroscopic analysis of N-confused meso-tetra(methoxyphenyl)porphyrins. J PORPHYR PHTHALOCYA 2021. [DOI: 10.1142/s1088424622500031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
UV, FL and IR spectra of isomer A (in DCM) and isomer B (in DMAc) of N-confused 5,10,15,20-tetra([Formula: see text]-methoxyphenyl)porphyrin ([Formula: see text]-isomer, 1), N-confused 5,10,15,20-tetra([Formula: see text]-methoxyphenyl)porphyrin ([Formula: see text]-isomer, 2) and N-confused 5,10,15,20-tetra([Formula: see text]-methoxyphenyl)porphyrin ([Formula: see text]-isomer,3) were investigated. Significant red shifts are observed from [Formula: see text]-isomer (1) to [Formula: see text]-isomer (3) in UV-vis absorption and fluorescence spectra. The fluorescence lifetime ([Formula: see text] of isomer A and isomer B of the samples (1, 2 and 3) are ca. 1.39[Formula: see text]1.79 ns and 1.68[Formula: see text]2.09 ns, respectively. In addition, the order of fluorescence quantum yield for isomer A is 1 > 2 > 3, but for isomer B it is 1 < 3 < 2. The isomer B of 2shows the strongest emission in accord with the strongest absorption. The isomer A of 1shows the strongest emission with the fluorescence quantum yield of 0.045, which is nearly double that of 3. The introduction of the methoxy group at the orthoposition increases steric hindrance, the molecular rigidity and the flow of [Formula: see text]-electron, thereby favourable to the fluorescence enhancement. The IR absorption peaks of 1, 2 and 3 were investigated and empirically assigned. The effects of the position of the substituents on the absorption frequency were also discussed. The absorption frequency of the C=C phenyl stretching in plane changed obviously by conjugative effect and steric effect when the methoxy group was at the orthoormetaposition in comparison with paraposition.
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Affiliation(s)
- Su-Hong Peng
- College of Chemistry and Bioengineering, Yichun University, Yichun 336000, China
| | - Li-Li Wang
- State Key Laboratory Optoelectronics Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, China
| | - Sha-Sha Cai
- College of Chemistry and Bioengineering, Yichun University, Yichun 336000, China
| | - Hui-Qing Xiao
- College of Chemistry and Bioengineering, Yichun University, Yichun 336000, China
| | - Xin-Tong Zhao
- College of Chemistry and Bioengineering, Yichun University, Yichun 336000, China
| | - Hui Wang
- State Key Laboratory Optoelectronics Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, China
| | - Hai-Yang Liu
- Department of Chemistry, South China University of Technology, Guangzhou 510641, China
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Wang L, Wan B, Lai S, Weng L, Liu H, Wang H. Light‐Induced Electron Transfer in Manganese(V)–Oxo Corroles. CHEMPHOTOCHEM 2021. [DOI: 10.1002/cptc.202000272] [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)
- Li‐Li Wang
- School of Physics Sun Yat-Sen University 510275 Guangzhou P. R. China
| | - Bei Wan
- Department of Chemistry South China University of Technology 510641 Guangzhou P. R. China
| | - Shu‐Hui Lai
- Department of Chemistry South China University of Technology 510641 Guangzhou P. R. China
| | - Lin‐Fang Weng
- School of Physics Sun Yat-Sen University 510275 Guangzhou P. R. China
| | - Hai‐Yang Liu
- Department of Chemistry South China University of Technology 510641 Guangzhou P. R. China
| | - Hui Wang
- School of Physics Sun Yat-Sen University 510275 Guangzhou P. R. China
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Shen HM, Liu L, Qi B, Hu MY, Ye HL, She YB. Efficient and selective oxidation of secondary benzylic C H bonds to ketones with O2 catalyzed by metalloporphyrins under solvent-free and additive-free conditions. MOLECULAR CATALYSIS 2020. [DOI: 10.1016/j.mcat.2020.111102] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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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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Shen HM, Qi B, Hu MY, Liu L, Ye HL, She YB. Selective Solvent-Free and Additive-Free Oxidation of Primary Benzylic C–H Bonds with O2 Catalyzed by the Combination of Metalloporphyrin with N-Hydroxyphthalimide. Catal Letters 2020. [DOI: 10.1007/s10562-020-03214-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Wang Q, Song M, Song X, Bu Y. Unexpected diradical character and large magnetic spin coupling in modified porphyrins induced by inverting pyrrole rings. Phys Chem Chem Phys 2019; 21:17209-17220. [PMID: 31343647 DOI: 10.1039/c9cp02691f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Porphyrin derivatives with inverted pyrrole rings have been experimentally synthesized, and their relevant electronic and magnetic properties have great application prospects in terms of electronic devices. In this work, we rationally design the structures and computationally investigate the electronic properties of porphine and Mg/Zn-porphyrin derivatives with two inverted pyrrole rings, i.e. the dipyrrole-inverted porphine and Mg/Zn-porphyrin analogues (1NN-2H, 2NN-2H, 1NN-Mg, 2NN-Mg, 1NN-Zn and 2NN-Zn), at the B3LYP/6-311G(d,p) level. The main structural characters of these porphyrin derivatives are that the [double bond splayed left]NH units of two pyrrole rings are inverted outwards and the porphyrin-like macrocycles are distorted from square to diamond shapes. More interestingly, these dipyrrole-inverted porphyrin derivatives present diradical characters with noticeably large antiferromagnetic spin coupling constants, i.e.-982.2/-936.3 cm-1 for 1NN-2H/2NN-2H, -796.3/-764.2 cm-1 for 1NN-Mg/2NN-Mg and -1044.5/-1055.2 cm-1 for 1NN-Zn/2NN-Zn, but their monopyrrole-inverted counterparts do not. Examinations of the orbital properties featuring large occupation numbers of the lowest unoccupied natural orbitals and two singly occupied molecular orbitals that are polarized in opposite directions also confirm these findings. These porphyrin derivatives have small singlet-triplet energy gaps and small energy gaps between the highest occupied molecular orbital and lowest unoccupied molecular orbital of the closed-shell singlet states. These are conducive to the emergence of diradical character and large spin coupling constants. Furthermore, the spin-alternation analyses show that each dipyrrole-inverted porphyrin derivative has two resonant structures featuring two spin-opposite single electrons, in agreement with the observed antiferromagnetic spin couplings. This work provides novel insights into the electronic structures and properties of the porphyrin derivatives with modified structures and also provides helpful information for the rational design, synthesis and characterization of new porphyrin-based magnets.
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Affiliation(s)
- Qi Wang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.
| | - Meiyu Song
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.
| | - Xinyu Song
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.
| | - Yuxiang Bu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.
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