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Wang H, Liu Y, Su C, Schulz CE, Fan Y, Bian Y, Li J. Perspectives on Ligand Properties of N-Heterocyclic Carbenes in Iron Porphyrin Complexes. Inorg Chem 2021; 61:847-856. [PMID: 34962794 DOI: 10.1021/acs.inorgchem.1c02444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
There has been considerable research interest in the ligand nature of N-heterocyclic carbenes (NHCs). In this work, two six-coordinate NHC iron porphyrin complexes [FeII(TTP)(1,3-Me2Imd)2] (TTP = tetratolylporphyrin, 1,3-Me2Imd = 1,3-dimethylimidazol-2-ylidene) and [FeIII(TDCPP)(1,3-Me2Imd)2]ClO4 (TDCPP = 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin) are reported. Single-crystal X-ray characterizations demonstrate that both complexes have strongly ruffled conformations and relatively perpendicular ligand orientations which are forced by the sterically bulky 1,3-Me2Imd NHC ligands. Multitemperature (4.2-300 K) and high magnetic field (0-9 T) Mössbauer and low-temperature (4.0 K) EPR spectroscopies definitely confirmed the low-spin states of [FeII(TTP)(1,3-Me2Imd)2] (S = 0) and [FeIII(TDCPP)(1,3-Me2Imd)2]ClO4 (S = 1/2). The similarity of 1,3-Me2Imd and imidazole, as well as the well-established correlations between the ligand nature and spectroscopic characteristics of [FeII,III(Porph)(L)2]0,+ (Porph: porphyrin; L: planar base ligand) species, allowed direct comparisons between the pair of ligands which revealed for the first time that NHC has a stronger π-acceptor ability than imidazoles, in addition to its very strong σ-donation.
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Affiliation(s)
- Haimang Wang
- College of Materials Science and Optoelectronic Technology & CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Yanqi Lake, Huairou District, Beijing 101408, China
| | - Yulong Liu
- College of Materials Science and Optoelectronic Technology & CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Yanqi Lake, Huairou District, Beijing 101408, China
| | - Chaorui Su
- Department of Chemistry, School of Chemistry and Biological Engineering, Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, and Daxing Research Institute, University of Science and Technology Beijing, Beijing 100083, China
| | - Charles E Schulz
- Department of Physics, Knox College, Galesburg, Illinois 61401, United States
| | - Yingying Fan
- College of Materials Science and Optoelectronic Technology & CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Yanqi Lake, Huairou District, Beijing 101408, China
| | - Yongzhong Bian
- Department of Chemistry, School of Chemistry and Biological Engineering, Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, and Daxing Research Institute, University of Science and Technology Beijing, Beijing 100083, China
| | - Jianfeng Li
- Department of Chemistry, School of Chemistry and Biological Engineering, Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, and Daxing Research Institute, University of Science and Technology Beijing, Beijing 100083, China
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Osadchuk I, Aav R, Borovkov V, Clot E. Chirogenesis in Zinc Porphyrins: Theoretical Evaluation of Electronic Transitions, Controlling Structural Factors and Axial Ligation. Chemphyschem 2021; 22:1817-1833. [PMID: 34213815 PMCID: PMC8457158 DOI: 10.1002/cphc.202100345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/24/2021] [Indexed: 12/15/2022]
Abstract
In the present work, sixteen different zinc porphyrins (possessing different meso substituents) with and without a chiral guest were modelled using DFT and TD-DFT approaches in order to understand the influence of various controlling factors on electronic circular dichroism (ECD) spectra. Two major aspects are influenced by these factors: excitation energy of the electronic transitions and their intensity. In the case of excitation energy, the influence increases in the following order: orientation of the peripheral substituents
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Affiliation(s)
- Irina Osadchuk
- Department of Chemistry and BiotechnologySchool of ScienceTallinn University of Technology AddressAkadeemia tee 1512618TallinnEstonia
- ICGMUniv MontpellierCNRS, ENSCMMontpellierFrance
| | - Riina Aav
- Department of Chemistry and BiotechnologySchool of ScienceTallinn University of Technology AddressAkadeemia tee 1512618TallinnEstonia
| | - Victor Borovkov
- Department of Chemistry and BiotechnologySchool of ScienceTallinn University of Technology AddressAkadeemia tee 1512618TallinnEstonia
| | - Eric Clot
- ICGMUniv MontpellierCNRS, ENSCMMontpellierFrance
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Zhan N, Wang H, Li J. Crystal structure of bis(1-ethyl-1 H-imidazole-κ N
3)( meso-tetramesitylporphyrinato-κ 4
N, N′, N′′, N′′′)iron(III) perchlorate chlorobenzene sesquisolvate. IUCRDATA 2019. [DOI: 10.1107/s2414314619007223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In the complex cation of title compound, [Fe(C56H52N4)(C5H8N2)2]ClO4·1.5C6H5Cl, the ironIII atom is coordinated in a distorted octahedral manner by four pyrrole N atoms of the porphyrin ring system in the equatorial plane, and by two N atoms of the 1-ethylimidazole ligands in the axial sites. A disordered perchlorate anion and one and a half chlorobenzene solvent molecules are also present. The cationic complex exhibits a highly ruffled porphyrin core. The average Fe—Np (Np is a porphyrin N atom) bond length is 1.988 (5), and the axial Fe—NIm (NIm is an imidazole N atom) bond lengths are 1.962 (3) and 1.976 (3) Å. The two 1-ethylimidazole ligands are inclined to each other by a dihedral angle of 68.62 (16)°. The dihedral angles between the 1-ethylimidazole planes and the planes of the closest Fe—Np vector are 28.52 (18) and 43.57 (13)°. Intermolecular C—H...Cl interactions are observed.
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