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Hou Y, Fang Y, Ou Z, Wang L, Xu W, Kadish KM. Electrochemical characterization of β,β′-butanoporphyrins containing sterically hindered meso-2,6-dihalogenophenyl substituents and first-row transition metal ions in nonaqueous media. J PORPHYR PHTHALOCYA 2021. [DOI: 10.1142/s1088424621500450] [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
Six [Formula: see text],[Formula: see text]-butano substituted metalloporphyrins containing sterically hindered meso-dihalogenophenyl substituents and first-row transition metal ions were synthesized and their electrochemical and spectroelectrochemical properties were characterized in nonaqueous media. The investigated compounds have the general formula butano(Y2Ph)4PorM, where Por is a dianion of the porphyrin, M = Mn[Formula: see text]Cl, Fe[Formula: see text]Cl, Co[Formula: see text], Ni[Formula: see text], Cu[Formula: see text] or Zn[Formula: see text]and Y2Ph is a sterically hindered 2,6-F2Ph or 2,6-Cl2Ph group on each of the four meso-positions of the macrocycle. The electrochemistry of each porphyrin was examined in CH2Cl2 or pyridine containing 0.1 M tetra-[Formula: see text]-butylammonium perchlorate. The first one-electron reduction is metal-centered for the manganese(III), iron(III) and cobalt(II) porphyrins to generate the Mn(II), Fe(II) and Co(I) porphyrins, but it is porphyrin ring-centered for the other examined M(II) porphyrins to give porphyrin [Formula: see text]-anion radicals under the given solution conditions. The effect of the [Formula: see text],[Formula: see text]-butano and sterically hindered meso-Y2Ph substituents on redox potentials and electron transfer mechanisms are discussed and compared to what was previously reported for butano-substituted tetraarylporphyrins without hindered meso-substituents.
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Affiliation(s)
- Yueping Hou
- Department of Chemical Engineering, Zhenjiang Vocational College, Zhenjiang, 212003, P. R. China
| | - Yuanyuan Fang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
- Department of Chemistry, University of Houston, Houston, Texas 77204-500, USA
| | - Zhongping Ou
- Department of Chemistry, University of Houston, Houston, Texas 77204-500, USA
| | - Liping Wang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
- Department of Chemistry, University of Houston, Houston, Texas 77204-500, USA
| | - Weijie Xu
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Karl M. Kadish
- Department of Chemistry, University of Houston, Houston, Texas 77204-500, USA
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Wang L, Fang Y, Xu W, Ou Z, Kadish KM. Electrochemical and spectroelectrochemical characterization of Cu(II) and Mn(III) tetrabutano- and tetrabenzoporphyrins containing sterically hindered meso -(2,6-difluorophenyl) substituents in nonaqueous media. J PORPHYR PHTHALOCYA 2019. [DOI: 10.1142/s1088424619501013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Four tetrabutano and tetrabenzoporphyrins containing sterically hindered meso-(2,6-difluorophenyl) substituents and copper(II) or manganese(III) central metal ions were synthesized and characterized as to their electrochemical and spectroelectrochemical properties in nonaqueous media. The copper(II) derivatives exhibit the expected two one-electron reductions to give [Formula: see text]-anion radicals and dianions in CH2Cl2. Electrochemical and spectroelectrochemical data suggest that a Cu(II) phlorin anion is generated from the doubly reduced Cu(II) butanoporphyrin and it is this species which undergoes the third reduction in pyridine. The first one-electron reduction of the Mn(III) porphyrins is metal-centered to give a Mn(II) compound, while the second and third reductions are macrocycle-centered to give Mn(II) porphyrin [Formula: see text]-anion radicals and dianions in both CH2Cl2 and pyridine. A Mn(II) phlorin anion is also generated from the Mn(II) dianion on the spectroelectrochemical timescale under the given solution conditions. The [Formula: see text],[Formula: see text]-butano and benzo groups have a significant effect on the measured redox potentials. Steric hindrance of the meso-(2,6-difluorophenyl) substituents also has an effect on the potential separation between the first two oxidations of the benzoporphyrins.
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Affiliation(s)
- Liping Wang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA
| | - Yuanyuan Fang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Weijie Xu
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Zhongping Ou
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA
| | - Karl M. Kadish
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA
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Fang Y, Wang L, Xu W, Ou Z, Chen M, Cong L, Shan W, Ke X, Kadish KM. Spectral, Electrochemical, and ESR Characterization of Manganese Tetraarylporphyrins Containing Four β,β'-Pyrrole Fused Butano and Benzo Groups in Nonaqueous Media. Inorg Chem 2019; 58:2576-2587. [PMID: 30721029 DOI: 10.1021/acs.inorgchem.8b03184] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two series of β,β'-pyrrole butano- and benzo-substituted mangenese(III) tetraarylporphyrins were synthesized and characterized with regard to their spectral and electrochemical properties. The investigated compounds have the general formula butano(Ar)4PorMnCl and benzo(Ar)4PorMnCl, where Por is the dianion of the porphyrin and Ar is a p-CH3Ph, Ph or p-ClPh group on each of the four meso-positions of the macrocycle. Each manganese(III) butano- or benzoporphyrin was examined in CH2Cl2 and/or pyridine containing 0.1 M tetra- n-butylammonium perchlorate and the data then were compared to that of the parent tetraarylporphyrins having the same meso-substituents. Up to four reductions are observed for each compound, the first being metal-centered to generate a Mn(II) porphyrin, and the second and third being porphyrin ring-centered to give a Mn(II) porphyrin π-anion radical and dianion, respectively. The one-electron reduced manganese porphyrins have an ESR spectrum with signals at g⊥= 5.6-5.8 and g// = 2.0, indicating a mixture of the four- and five-coordinated Mn(II) complexes in a high-spin state (3d5, S = 5/2, I = 5/2). Data from cyclic voltammetry and spectroelectrochemistry both suggest that formation of the porphyrin dianion is followed by a chemical reaction at the electrode surface to give an electroactive phlorin anion. The effects of solvent and porphyrin substituents on ultraviolet-visible light (UV-vis) spectra, redox potentials, and electron transfer mechanisms are discussed.
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Affiliation(s)
- Yuanyuan Fang
- School of Chemistry and Chemical Engineering , Jiangsu University , Zhenjiang , 212013 , China
| | - Liping Wang
- School of Chemistry and Chemical Engineering , Jiangsu University , Zhenjiang , 212013 , China
| | - Weijie Xu
- School of Chemistry and Chemical Engineering , Jiangsu University , Zhenjiang , 212013 , China
| | - Zhongping Ou
- Department of Chemistry , University of Houston , Houston , Texas 77204-5003 , United States
| | - Mingyuan Chen
- School of Chemistry and Chemical Engineering , Jiangsu University , Zhenjiang , 212013 , China.,Department of Chemistry , University of Houston , Houston , Texas 77204-5003 , United States
| | - Lei Cong
- Department of Chemistry , University of Houston , Houston , Texas 77204-5003 , United States
| | - Wenqian Shan
- Department of Chemistry , University of Houston , Houston , Texas 77204-5003 , United States
| | - Xiangyi Ke
- Department of Chemistry , University of Houston , Houston , Texas 77204-5003 , United States
| | - Karl M Kadish
- Department of Chemistry , University of Houston , Houston , Texas 77204-5003 , United States
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Ye L, Fang Y, Ou Z, Wang L, Xue S, Sun J, Kadish KM. Electrochemistry of zinc tetraarylporphyrins containing fused butano and benzo groups. Effect of solvent and substituents on spectra, potentials and mechanism in nonaqueous media. J PORPHYR PHTHALOCYA 2018. [DOI: 10.1142/s1088424618501067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Two series of zinc tetraarylporphyrins containing four [Formula: see text],[Formula: see text]′-pyrrole fused butano or benzo groups were synthesized and characterized as to their electrochemical and spectroelectrochemical properties in nonaqueous media. The examined compounds are represented as butano(Ar)4PorZn and benzo(Ar)4PorZn, where Por is the porphyrin dianion and Ar is a [Formula: see text]-CH3Ph, Ph or [Formula: see text]-ClPh substitutent on [Formula: see text]-positions of the macrocycle. Each Zn(II) butano- and benzoporphyrin undergoes two one-electron reductions to give a [Formula: see text]-anion radical and dianion in CH2Cl2. In contrast, three reductions were observed for the benzoporphyrin derivatives in pyridine, the third of which is assigned as electron addition to a benzophlorin anion generated from the doubly reduced benzoporphyrin. Two overlapped one-electron oxidations were observed for the butanoporphyrins in CH2Cl2, a result not previously observed for any other zinc porphyrin. The electrochemically measured HOMO-LUMO gap of the benzoporphyrins ranges from 1.89 to 1.90 V in CH2Cl2 and from 1.93 to 1.95 V in pyridine. Both values are smaller than the gaps of butanoporphyrins at 2.11-2.13 V in CH2Cl2 and 2.07.2.09 V in pyridine.
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Affiliation(s)
- Lina Ye
- College of Computer, Jilin Normal University, Siping 136000, P. R. China
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Yuanyuan Fang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Zhongping Ou
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA
| | - Liping Wang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA
| | - Songlin Xue
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Jing Sun
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
| | - Karl M. Kadish
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA
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