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Mukhopadhyaya A, Ali ME. Can Iron-Porphyrins Behave as Single-Molecule Magnets? J Phys Chem A 2024. [PMID: 38504619 DOI: 10.1021/acs.jpca.4c00430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
The study of magnetic properties, especially the magnetic anisotropy of iron-porphyrin complexes employing multiconfigurational methods, is quite challenging due to many strongly correlated electrons in nearly degenerate orbitals. However, a prerequisite for observing the magnetic anisotropy and slow magnetization relaxation, the zero-field splitting parameter, D, was experimentally observed decades ago for halide-based axially ligated penta-coordinate Fe(III)-porphyrins. In these complexes, the signs of D were reported mostly as positive; in a few cases, inconclusive signs of the D parameter were also mentioned. However, no ab initio calculations have been reported to shed light on this. Deciphering the electronic structure of these penta-coordinated complexes employing the complete active space self-consistent field method and N-electron valence second-order perturbation theory, we confirm the positive D values. However, a negative D value is highly desired to observe the single-molecule magnet properties without an external magnetic field, which we observed in the Fe(II)-porphyrin complexes with axial imidazole ligands instead of halide ligands. The detailed analysis of the multireference wave functions unravels the role of axial ligands in determining the sign and magnitude of the D parameters.
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Affiliation(s)
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Mohali, Punjab 140306, India
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2
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Affiliation(s)
- Milica Feldt
- Leibniz Institute for Catalysis: Leibniz-Institut fur Katalyse eV Theory & Catalysis Albert-Einstein-Str 29A 18059 Rostock GERMANY
| | - Quan Manh Phung
- Nagoya University: Nagoya Daigaku Department of Chemistry JAPAN
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3
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Xu L, Xie Z, Zenere KA, Clegg JK, Kenny E, Rijs NJ, Jameson GNL, Kepert CJ, Powell BJ, Neville SM. Co-existence of five- and six-coordinate iron( ii) species captured in a geometrically strained spin-crossover Hofmann framework. Dalton Trans 2022; 51:9596-9600. [DOI: 10.1039/d2dt01371a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The use of an angular ligand drives the formation of an irregular Hofmann framework whereby 6-coordinate and rare 5-coordinate FeII species co-exist – the 6-coordinate species show a spin-crossover transition.
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Affiliation(s)
- Luonan Xu
- School of Chemistry, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Zixi Xie
- School of Chemistry, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Katrina A. Zenere
- School of Chemistry, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Jack K. Clegg
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Elise Kenny
- School of School of Mathematics and Physics, The University of Queensland, St Lucia 4072, Queensland, Australia
| | - Nicole J. Rijs
- School of Chemistry, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Guy N. L. Jameson
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Cameron J. Kepert
- School of Chemistry, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Benjamin J. Powell
- School of School of Mathematics and Physics, The University of Queensland, St Lucia 4072, Queensland, Australia
| | - Suzanne M. Neville
- School of Chemistry, The University of New South Wales, Sydney, New South Wales, 2052, Australia
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4
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Fateminasab F, Aarabi M, de la Lande A, Omidyan R. Theoretical insights on the effect of environments on binding of CO to the Heme :Ferrous and Ferric systems. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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5
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Zhao J, Peng Q, Wang Z, Xu W, Xiao H, Wu Q, Sun HL, Ma F, Zhao J, Sun CJ, Zhao J, Li J. Proton mediated spin state transition of cobalt heme analogs. Nat Commun 2019; 10:2303. [PMID: 31127106 PMCID: PMC6534676 DOI: 10.1038/s41467-019-10357-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 05/02/2019] [Indexed: 11/17/2022] Open
Abstract
The spin state transition from low spin to high spin upon substrate addition is one of the key steps in cytochrome P450 catalysis. External perturbations such as pH and hydrogen bonding can also trigger the spin state transition of hemes through deprotonated histidine (e.g. Cytochrome c). In this work, we report the isolated 2-methylimidazole Cobalt(II) [Co(TPP)(2-MeHIm)] and [Co(TTP)(2-MeHIm)], and the corresponding 2-methylimidazolate derivatives where the N−H proton of axial 2-MeHIm is removed. Interestingly, various spectroscopies including EPR and XAFS determine a high-spin state (S = 3/2) for the imidazolate derivatives, in contrast to the low-spin state (S = 1/2) of all known imidazole analogs. DFT assisted stereoelectronic investigations are applied to understand the metal-ligand interactions, which suggest that the dramatically displaced metal center allowing a promotion eg(dπ) → b1g(\documentclass[12pt]{minimal}
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\begin{document}$$d_{x^2 - y^2}$$\end{document}dx2-y2) is crucial for the occurrence of the spin state transition. Studying the electronic structures and spin transitions of synthetic heme analogs is crucial to advancing our understanding of heme enzyme mechanisms. Here the authors show that a Co(II) porphyrin complex undergoes an unexpected spin state transition upon deprotonation of its axial imidazole ligand.
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Affiliation(s)
- Jianping Zhao
- College of Materials Science and Opto-electronic Technology, CAS Center for Excellence in Topological Quantum Computation, & Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Yanqi Lake, Huairou District, 101408, Beijing, China
| | - Qian Peng
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 300071, Tianjin, China
| | - Zijian Wang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 300071, Tianjin, China
| | - Wei Xu
- Institute of High Energy Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100049, Beijing, China
| | - Hongyan Xiao
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, China
| | - Qi Wu
- College of Materials Science and Opto-electronic Technology, CAS Center for Excellence in Topological Quantum Computation, & Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Yanqi Lake, Huairou District, 101408, Beijing, China
| | - Hao-Ling Sun
- Department of Chemistry and Beijing Key Laboratory of Energy Conversion and Storage Materials, Beijing Normal University, 100875, Beijing, China
| | - Fang Ma
- Department of Chemistry and Beijing Key Laboratory of Energy Conversion and Storage Materials, Beijing Normal University, 100875, Beijing, China
| | - Jiyong Zhao
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Cheng-Jun Sun
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Jianzhang Zhao
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, West Campus, 2 Ling-Gong Road, 116024, Dalian, China
| | - Jianfeng Li
- College of Materials Science and Opto-electronic Technology, CAS Center for Excellence in Topological Quantum Computation, & Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Yanqi Lake, Huairou District, 101408, Beijing, China.
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6
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Adam SM, Wijeratne GB, Rogler PJ, Diaz DE, Quist DA, Liu JJ, Karlin KD. Synthetic Fe/Cu Complexes: Toward Understanding Heme-Copper Oxidase Structure and Function. Chem Rev 2018; 118:10840-11022. [PMID: 30372042 PMCID: PMC6360144 DOI: 10.1021/acs.chemrev.8b00074] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Heme-copper oxidases (HCOs) are terminal enzymes on the mitochondrial or bacterial respiratory electron transport chain, which utilize a unique heterobinuclear active site to catalyze the 4H+/4e- reduction of dioxygen to water. This process involves a proton-coupled electron transfer (PCET) from a tyrosine (phenolic) residue and additional redox events coupled to transmembrane proton pumping and ATP synthesis. Given that HCOs are large, complex, membrane-bound enzymes, bioinspired synthetic model chemistry is a promising approach to better understand heme-Cu-mediated dioxygen reduction, including the details of proton and electron movements. This review encompasses important aspects of heme-O2 and copper-O2 (bio)chemistries as they relate to the design and interpretation of small molecule model systems and provides perspectives from fundamental coordination chemistry, which can be applied to the understanding of HCO activity. We focus on recent advancements from studies of heme-Cu models, evaluating experimental and computational results, which highlight important fundamental structure-function relationships. Finally, we provide an outlook for future potential contributions from synthetic inorganic chemistry and discuss their implications with relevance to biological O2-reduction.
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Affiliation(s)
- Suzanne M. Adam
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Gayan B. Wijeratne
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Patrick J. Rogler
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Daniel E. Diaz
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - David A. Quist
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Jeffrey J. Liu
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Kenneth D. Karlin
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
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7
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Abstract
The synthesis and structural analysis of two new bis imidazole-ligated iron(II) porphyrinates are reported. The reacting porphyrin used in the studies was the four-coordinate [Formula: see text] atropisomer of [Fe(TpivPP)] (picket fence porphyrin); the axial ligands are 2-methylimidazole and 1,2-dimethylimidazole. Crystal structure analysis revealed that the [Fe(TpivPP)(2-MeHIm)[Formula: see text]] complex had a strongly ruffled porphyrin core that accommodated the hindered ligands on both the picket side and the open face of the porphyrin. Reaction with 1,2-dimethylimidazole with the four-coordinate [Fe(TpivPP)] starting material led to an isomerized form of the picket fence porphyrin. The structure analysis showed that the product obtained was the [Formula: see text] atropisomer. Strong ruffling caused by the bulky 1,2-dimethylimidazole ligand must allow the requisite rotation about the methine carbon to phenyl carbon single bond and yields what is probably the most stable form of the complex. The relative orientation of the two axial ligands in both complexes are approximately perpendicular to each other. Other structural parameters are in general accord with six-coordinate iron(II) porphyrinates.
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Affiliation(s)
- Haimang Wang
- School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, YanQi Lake, HuaiRou District, Beijing 101408, China
| | - Jianfeng Li
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, YanQi Lake, HuaiRou District, Beijing 101408, China
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - W. Robert Scheidt
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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8
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Hu C, Oliver AG, Turowska-Tyrk I, Scheidt WR. A study of the effect of axial ligand steric hindrance. J PORPHYR PHTHALOCYA 2018. [DOI: 10.1142/s1088424618500700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The molecular structures of three porphyrinate derivatives have been determined by X-ray studies. Two derivatives, [Fe(TTP)(1-MeIm)[Formula: see text]] · 2C[Formula: see text]H[Formula: see text] and [Fe(T-[Formula: see text]-OCH[Formula: see text]PP)(BzHIm)[Formula: see text]] are iron(II) derivatives, whereas the third, [Fe(TMP)(BzHIm)[Formula: see text]]ClO[Formula: see text] · 2CHCl[Formula: see text], is an iron(III) species. The structure determinations provide evidence of the importance of steric effects, either from the axial ligand or the porphyrin ligand, in defining the overall stereochemistry.
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Affiliation(s)
- Chuanjiang Hu
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, Jiangsu, China
| | - Allen G. Oliver
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Ilona Turowska-Tyrk
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
- Present address: Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50–370 Wrocław, Poland
| | - W. Robert Scheidt
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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9
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Hu C, Noll BC, Schulz CE, Scheidt WR. Hydrogen-Bonding Effects in Five-Coordinate High-Spin Imidazole-Ligated Iron(II) Porphyrinates. Inorg Chem 2018; 57:793-803. [PMID: 29281268 DOI: 10.1021/acs.inorgchem.7b02744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The influence of hydrogen binding to the N-H group of coordinated imidazole in high-spin iron(II) porphyrinates has been studied. The preparation and characterization of new complexes based on [Fe(TPP)(2-MeHIm)] (TPP is the dianion of tetraphenylporphyrin) are reported. The hydrogen bond acceptors are ethanol, tetramethylene sulfoxide, and 2-methylimidazole. The last acceptor, 2-MeHIm, was found in a crystalline complex with two [Fe(TPP)(2-MeHIm)] sites, only one of which has the 2-methylimidazole hydrogen bond acceptor. This latter complex has been studied by temperature-dependent Mössbauer spectroscopy. All new complexes have also been characterized by X-ray structure determinations. The Fe-NP and Fe-NIm bond lengths, and displacement of the Fe atom out of the porphyrin plane are similar to, but marginally different than, those in imidazole-ligated species with no hydrogen bond. All the structural and Mössbauer properties suggest that these new hydrogen-bonded species have the same electronic configuration as imidazole-ligated species with no hydrogen bond. These new studies continue to show that the effects of hydrogen bonding in five-coordinate high-spin iron(II) systems are subtle and challenging to understand.
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Affiliation(s)
- Chuanjiang Hu
- Contribution from State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou 215123, Jiangsu, People's Republic of China.,The Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Bruce C Noll
- The Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Charles E Schulz
- Department of Physics, Knox College , Galesburg, Illinois 61401, United States
| | - W Robert Scheidt
- The Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
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10
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Gell DA. Structure and function of haemoglobins. Blood Cells Mol Dis 2017; 70:13-42. [PMID: 29126700 DOI: 10.1016/j.bcmd.2017.10.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Revised: 10/29/2017] [Accepted: 10/30/2017] [Indexed: 12/18/2022]
Abstract
Haemoglobin (Hb) is widely known as the iron-containing protein in blood that is essential for O2 transport in mammals. Less widely recognised is that erythrocyte Hb belongs to a large family of Hb proteins with members distributed across all three domains of life-bacteria, archaea and eukaryotes. This review, aimed chiefly at researchers new to the field, attempts a broad overview of the diversity, and common features, in Hb structure and function. Topics include structural and functional classification of Hbs; principles of O2 binding affinity and selectivity between O2/NO/CO and other small ligands; hexacoordinate (containing bis-imidazole coordinated haem) Hbs; bacterial truncated Hbs; flavohaemoglobins; enzymatic reactions of Hbs with bioactive gases, particularly NO, and protection from nitrosative stress; and, sensor Hbs. A final section sketches the evolution of work on the structural basis for allosteric O2 binding by mammalian RBC Hb, including the development of newer kinetic models. Where possible, reference to historical works is included, in order to provide context for current advances in Hb research.
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Affiliation(s)
- David A Gell
- School of Medicine, University of Tasmania, TAS 7000, Australia.
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11
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Scheidt WR, Li J, Sage JT. What Can Be Learned from Nuclear Resonance Vibrational Spectroscopy: Vibrational Dynamics and Hemes. Chem Rev 2017; 117:12532-12563. [PMID: 28921972 PMCID: PMC5639469 DOI: 10.1021/acs.chemrev.7b00295] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
Nuclear resonance
vibrational spectroscopy (NRVS; also known as
nuclear inelastic scattering, NIS) is a synchrotron-based method that
reveals the full spectrum of vibrational dynamics for Mössbauer
nuclei. Another major advantage, in addition to its completeness (no
arbitrary optical selection rules), is the unique selectivity of NRVS.
The basics of this recently developed technique are first introduced
with descriptions of the experimental requirements and data analysis
including the details of mode assignments. We discuss the use of NRVS
to probe 57Fe at the center of heme and heme protein derivatives
yielding the vibrational density of states for the iron. The application
to derivatives with diatomic ligands (O2, NO, CO, CN–) shows the strong capabilities of identifying mode
character. The availability of the complete vibrational spectrum of
iron allows the identification of modes not available by other techniques.
This permits the correlation of frequency with other physical properties.
A significant example is the correlation we find between the Fe–Im
stretch in six-coordinate Fe(XO) hemes and the trans Fe–N(Im)
bond distance, not possible previously. NRVS also provides uniquely
quantitative insight into the dynamics of the iron. For example, it
provides a model-independent means of characterizing the strength
of iron coordination. Prediction of the temperature-dependent mean-squared
displacement from NRVS measurements yields a vibrational “baseline”
for Fe dynamics that can be compared with results from techniques
that probe longer time scales to yield quantitative insights into
additional dynamical processes.
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Affiliation(s)
- W Robert Scheidt
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556 United States
| | - Jianfeng Li
- College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences , YanQi Lake, HuaiRou District, Beijing 101408, China
| | - J Timothy Sage
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University , 120 Forsyth Street, Boston, Massachusetts 02115, United States
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12
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Roy B, Saha R, Ghosh AK, Patil Y, Mukherjee PS. Versatility of Two Diimidazole Building Blocks in Coordination-Driven Self-Assembly. Inorg Chem 2017; 56:3579-3588. [DOI: 10.1021/acs.inorgchem.7b00037] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Bijan Roy
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India
| | - Rupak Saha
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India
| | - Aloke Kumar Ghosh
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India
| | - Yogesh Patil
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India
| | - Partha Sarathi Mukherjee
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India
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13
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Hu B, He M, Yao Z, Schulz CE, Li J. Unique Axial Imidazole Geometries of Fully Halogenated Iron(II) Porphyrin Complexes: Crystal Structures and Mössbauer Spectroscopic Studies. Inorg Chem 2016; 55:9632-9643. [DOI: 10.1021/acs.inorgchem.6b01364] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Bin Hu
- College
of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Yanqi Lake, Huairou District, Beijing 101408, China
| | - Mingrui He
- College
of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Yanqi Lake, Huairou District, Beijing 101408, China
| | - Zhen Yao
- College
of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Yanqi Lake, Huairou District, Beijing 101408, China
| | - Charles E. Schulz
- Department
of Physics, Knox College, Galesburg, Illinois 61401, United States
| | - Jianfeng Li
- College
of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Yanqi Lake, Huairou District, Beijing 101408, China
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14
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Peng Q, Pavlik JW, Silvernail NJ, Alp EE, Hu MY, Zhao J, Sage JT, Scheidt WR. 3D Motions of Iron in Six-Coordinate {FeNO}(7) Hemes by Nuclear Resonance Vibration Spectroscopy. Chemistry 2016; 22:6323-6332. [PMID: 26999733 PMCID: PMC4999340 DOI: 10.1002/chem.201505155] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Indexed: 11/08/2022]
Abstract
The vibrational spectrum of a six-coordinate nitrosyl iron porphyrinate, monoclinic [Fe(TpFPP)(1-MeIm)(NO)] (TpFPP=tetra-para-fluorophenylporphyrin; 1-MeIm=1-methylimidazole), has been studied by oriented single-crystal nuclear resonance vibrational spectroscopy (NRVS). The crystal was oriented to give spectra perpendicular to the porphyrin plane and two in-plane spectra perpendicular or parallel to the projection of the FeNO plane. These enable assignment of the FeNO bending and stretching modes. The measurements reveal that the two in-plane spectra have substantial differences that result from the strongly bonded axial NO ligand. The direction of the in-plane iron motion is found to be largely parallel and perpendicular to the projection of the bent FeNO on the porphyrin plane. The out-of-plane Fe-N-O stretching and bending modes are strongly mixed with each other, as well as with porphyrin ligand modes. The stretch is mixed with v50 as was also observed for dioxygen complexes. The frequency of the assigned stretching mode of eight Fe-X-O (X=N, C, and O) complexes is correlated with the Fe-XO bond lengths. The nature of highest frequency band at ≈560 cm(-1) has also been examined in two additional new derivatives. Previously assigned as the Fe-NO stretch (by resonance Raman), it is better described as the bend, as the motion of the central nitrogen atom of the FeNO group is very large. There is significant mixing of this mode. The results emphasize the importance of mode mixing; the extent of mixing must be related to the peripheral phenyl substituents.
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Affiliation(s)
- Qian Peng
- Contribution from Department of Chemistry and Biochemistry, University of Notre Dame, University of Notre Dame, Notre Dame, Indiana 46556 USA
| | - Jeffrey W. Pavlik
- Contribution from Department of Chemistry and Biochemistry, University of Notre Dame, University of Notre Dame, Notre Dame, Indiana 46556 USA
| | - Nathan J. Silvernail
- Contribution from Department of Chemistry and Biochemistry, University of Notre Dame, University of Notre Dame, Notre Dame, Indiana 46556 USA
| | - E. Ercan Alp
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Michael Y. Hu
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Jiyong Zhao
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - J. Timothy Sage
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, 120 Forsyth Street, Boston, MA 02115, USA
| | - W. Robert Scheidt
- Contribution from Department of Chemistry and Biochemistry, University of Notre Dame, University of Notre Dame, Notre Dame, Indiana 46556 USA
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15
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Todde G, Hovmöller S, Laaksonen A. Influence of mutations at the proximal histidine position on the Fe-O2 bond in hemoglobin from density functional theory. J Chem Phys 2016; 144:095101. [PMID: 26957180 DOI: 10.1063/1.4942614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Four mutated hemoglobin (Hb) variants and wild type hemoglobin as a reference have been investigated using density functional theory methods focusing on oxygen binding. Dispersion-corrected B3LYP functional is used and found to provide reliable oxygen binding energies. It also correctly reproduces the spin distribution of both bound and free heme groups as well as provides correct geometries at their close vicinity. Mutations in hemoglobin are not only an intrigued biological problem and it is also highly important to understand their effects from a clinical point of view. This study clearly shows how even small structural differences close to the heme group can have a significant effect in reducing the oxygen binding of mutated hemoglobins and consequently affecting the health condition of the patient suffering from the mutations. All of the studied mutated Hb variants did exhibit much weaker binding of molecular oxygen compared to the wild type of hemoglobin.
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Affiliation(s)
- Guido Todde
- Division of Physical Chemistry, Arrhenius Laboratory, Department of Materials and Environmental Chemistry, Stockholm University, S 106 91 Stockholm, Sweden
| | - Sven Hovmöller
- Division of Structural Chemistry, Arrhenius Laboratory, Department of Materials and Environmental Chemistry, Stockholm University, S 106 91 Stockholm, Sweden
| | - Aatto Laaksonen
- Division of Physical Chemistry, Arrhenius Laboratory, Department of Materials and Environmental Chemistry, Stockholm University, S 106 91 Stockholm, Sweden
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16
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Discovery of the magnetic behavior of hemoglobin: A beginning of bioinorganic chemistry. Proc Natl Acad Sci U S A 2016; 112:13123-7. [PMID: 26508205 DOI: 10.1073/pnas.1515704112] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two articles published by Pauling and Coryell in PNAS nearly 80 years ago described in detail the magnetic properties of oxy- and deoxyhemoglobin, as well as those of closely related compounds containing hemes. Their measurements revealed a large difference in magnetism between oxygenated and deoxygenated forms of the protein and, along with consideration of the observed diamagnetism of the carbonmonoxy derivative, led to an electronic structural formulation of oxyhemoglobin. The key role of hemoglobin as the main oxygen carrier in mammalian blood had been established earlier, and its allosteric behavior had been described in the 1920s. The Pauling-Coryell articles on hemoglobin represent truly seminal contributions to the field of bioinorganic chemistry because they are the first to make connections between active site electronic structure and the function of a metalloprotein.
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Zhao H, Fang C, Gao J, Liu C. Spin-state energies of heme-related models from spin-flip TDDFT calculations. Phys Chem Chem Phys 2016; 18:29486-29494. [DOI: 10.1039/c6cp04826a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The spin-state energies of heme-related models were calculated by using the spin-flip TDDFT method avoiding spin contamination.
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Affiliation(s)
- Hui Zhao
- Institute of Theoretical Chemistry
- School of Chemistry & Chemical Engineering
- Shandong University
- Jinan
- People's Republic of China
| | - Changfeng Fang
- Department of Physics
- Jining University
- Qufu
- People's Republic of China
| | - Jun Gao
- Institute of Theoretical Chemistry
- School of Chemistry & Chemical Engineering
- Shandong University
- Jinan
- People's Republic of China
| | - Chengbu Liu
- Institute of Theoretical Chemistry
- School of Chemistry & Chemical Engineering
- Shandong University
- Jinan
- People's Republic of China
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18
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Abstract
A common structural motif in heme proteins is a five-coordinate species in which the iron is coordinated by a histidyl residue. The widely distributed heme proteins with this motif are essential for the well being of humans and other organisms. We detail the differences in molecular structures and physical properties of high-spin iron(ii) porphyrin derivatives ligated by neutral imidazole, hydrogen bonded imidazole, and imidazolate or other anions. Two distinct (high spin) electronic states are observed that have differing d-orbital occupancies and discernibly different five-coordinate square-pyramidal coordination groups. The doubly occupied orbital in the imidazole species is a low symmetry orbital oblique to the heme plane whereas in the imidazolate species the doubly occupied orbital is a high symmetry orbital in the heme plane, i.e., the primary doubly-occupied d-orbital is different. Methods that can be used to classify a particular complex into one or the other state include X-ray structure determinations, high-field Mössbauer spectroscopy, vibrational spectroscopy, magnetic circular dichroism, and even-spin EPR spectroscopy. The possible functional significance of the ground state differences has not been established for heme proteins, but is likely found in the pathways for oxygen transport vs. oxygen utilization.
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19
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Yu Q, Liu Y, Liu D, Li J. Geometric and electronic structures of five-coordinate manganese(ii) “picket fence” porphyrin complexes. Dalton Trans 2015; 44:9382-90. [DOI: 10.1039/c5dt00685f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The X-ray structural investigation rationalized the variable axial ligand distances. EPR revealed five resonance positions and the simulations gave reasonable zero field splitting parameters.
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Affiliation(s)
- Qiang Yu
- Research Institute of Applied Chemistry
- Shanxi University
- Taiyuan
- China
- College of Materials Science and Opto-electronic Technology
| | - Yanhong Liu
- Technical Institute of Physics and Chemistry
- Beijing
- China
| | - Diansheng Liu
- Research Institute of Applied Chemistry
- Shanxi University
- Taiyuan
- China
| | - Jianfeng Li
- College of Materials Science and Opto-electronic Technology
- University of Chinese Academy of Sciences
- Beijing
- China
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20
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Radoń M. Spin-State Energetics of Heme-Related Models from DFT and Coupled Cluster Calculations. J Chem Theory Comput 2014; 10:2306-21. [DOI: 10.1021/ct500103h] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Mariusz Radoń
- Faculty of Chemistry, Jagiellonian University in Kraków, ul. Ingardena 3, 30-060 Kraków, Poland
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21
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Broclawik E, Stępniewski A, Radoń M. Nitric oxide as a non-innocent ligand in (bio-)inorganic complexes: spin and electron transfer in Fe(II)-NO bond. J Inorg Biochem 2014; 136:147-53. [PMID: 24495545 DOI: 10.1016/j.jinorgbio.2014.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 01/10/2014] [Accepted: 01/10/2014] [Indexed: 11/27/2022]
Abstract
The nature of electron density transfer upon bond formation between NO ligand and Fe(II) center is analyzed on the basis of DFT calculation for two {Fe-NO}(7) complexes with entirely diverse geometric and electronic structures: Fe(II)P(NH3)NO (with bent Fe-N-O unit) and [Fe(II)(H2O)5(NO)](2+) (with linear Fe-N-O structure). Proper identification of an electronic status of the fragments, "prepared" to make a bond, was found necessary to get meaningful resolution of charge and spin transfer processes from a spin-resolved analysis of natural orbitals for chemical valence. The Fe(II)P(NH3)NO adduct (built of NO(0) (S=1/2) and Fe(II)P(NH3) (S=0) fragments) showed a strong π*-backdonation competing with spin transfer via a σ-donation, yielding significant red-shift of the NO stretching frequency. [Fe(II)(H2O)5(NO)](2+) (built of NO(0) (S=1/2) antiferromagnetically coupled to Fe(II)(H2O)5 (S=2) fragment) gave no noticeable charge or spin transfer between fragments; a slight blue-shift of the NO stretching frequency could be related to a residual π-donation due to weak π-bonding.
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Affiliation(s)
- Ewa Broclawik
- Jerzy Haber Institute of Catalysis PAS, ul. Niezapominajek 8, 30-239 Krakow, Poland.
| | - Adam Stępniewski
- Jerzy Haber Institute of Catalysis PAS, ul. Niezapominajek 8, 30-239 Krakow, Poland
| | - Mariusz Radoń
- Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland
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22
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Li J, Noll BC, Oliver AG, Schulz CE, Scheidt WR. Correlated ligand dynamics in oxyiron picket fence porphyrins: structural and Mössbauer investigations. J Am Chem Soc 2013; 135:15627-41. [PMID: 24025123 PMCID: PMC3827975 DOI: 10.1021/ja408431z] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Disorder in the position of the dioxygen ligand is a well-known problem in dioxygen complexes and, in particular, those of picket fence porphyrin species. The dynamics of Fe-O2 rotation and tert-butyl motion in three different picket fence porphyrin derivatives has been studied by a combination of multitemperature X-ray structural studies and Mössbauer spectroscopy. Structural studies show that the motions of the dioxygen ligand also require motions of the protecting pickets of the ligand binding pocket. The two motions appear to be correlated, and the temperature-dependent change in the O2 occupancies cannot be governed by a simple Boltzmann distribution. The three [Fe(TpivPP)(RIm)(O2)] derivatives studied have RIm = 1-methyl-, 1-ethyl-, or 2-methylimidazole. In all three species there is a preferred orientation of the Fe-O2 moiety with respect to the trans imidazole ligand and the population of this orientation increases with decreasing temperature. In the 1-MeIm and 1-EtIm species the Fe-O2 unit is approximately perpendicular to the imidazole plane, whereas in the 2-MeHIm species the Fe-O2 unit is approximately parallel. This reflects the low energy required for rotation of the Fe-O2 unit and the small energy differences in populating the possible pocket quadrants. All dioxygen complexes have a crystallographically required 2-fold axis of symmetry that limits the accuracy of the determined Fe-O2 geometry. However, the 80 K structure of the 2-MeHIm derivative allowed for resolution of the two bonded oxygen atom positions and provided the best geometric description for the Fe-O2 unit. The values determined are Fe-O = 1.811(5) Å, Fe-O-O = 118.2(9)°, O-O = 1.281(12) Å, and an off-axis tilt of 6.2°. Demonstration of the off-axis tilt is a first. We present detailed temperature-dependent simulations of the Mössbauer spectra that model the changing value of the quadrupole splitting and line widths. Residuals to fits are poorer at higher temperature. We believe that this is consistent with the idea that population of the two conformers is related to the concomitant motions of both Fe-O2 rotations and motions of the protecting tert-butyl pickets.
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Affiliation(s)
- Jianfeng Li
- To whom correspondence should be addressed. JL: , CES: , WRS:
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23
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Peng Q, Li M, Hu C, Pavlik JW, Oliver AG, Alp EE, Hu MY, Zhao J, Sage JT, Scheidt WR. Probing heme vibrational anisotropy: an imidazole orientation effect? Inorg Chem 2013; 52:11361-9. [PMID: 24020589 DOI: 10.1021/ic401644g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The complete iron vibrational spectrum of the five-coordinate high-spin complex [Fe(OEP)(2-MeHIm)], where OEP = octaethylporphyrinato and 2-MeHIm = 2-methylimidazole, has been obtained by oriented single-crystal nuclear resonance vibrational spectroscopy (NRVS) data. Measurements have been made in three orthogonal directions, which provides quantitative information for all iron motion. These experimental data, buttressed by density functional theory (DFT) calculations, have been used to define the effects of the axial ligand orientation. Although the axial imidazole removes the degeneracy in the in-plane vibrations, the imidazole orientation does not appear to control the direction of the in-plane iron motion. This is in contrast to the effect of the imidazolate ligand, as defined by DFT calculations, which does have substantial effects on the direction of the in-plane iron motion. The axial NO ligand has been found to have the strongest orientational effect (Angew. Chem., Int. Ed., 2010, 49, 4400). Thus the strength of the directional properties are in the order NO > imidazolate > imidazole, consistent with the varying strength of the Fe-ligand bond.
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Affiliation(s)
- Qian Peng
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
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24
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Hu C, Peng Q, Silvernail NJ, Barabanschikov A, Zhao J, Alp EE, Sturhahn W, Sage JT, Scheidt WR. Effects of imidazole deprotonation on vibrational spectra of high-spin iron(II) porphyrinates. Inorg Chem 2013; 52:3170-7. [PMID: 23470205 PMCID: PMC3613136 DOI: 10.1021/ic3026396] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effects of the deprotonation of coordinated imidazole on the vibrational dynamics of five-coordinate high-spin iron(II) porphyrinates have been investigated using nuclear resonance vibrational spectroscopy. Two complexes have been studied in detail with both powder and oriented single-crystal measurements. Changes in the vibrational spectra are clearly related to structural differences in the molecular structures that occur when imidazole is deprotonated. Most modes involving the simultaneous motion of iron and imidazolate are unresolved, but the one mode that is resolved is found at higher frequency in the imidazolates. These out-of-plane results are in accord with earlier resonance Raman studies of heme proteins. We also show the imidazole vs imidazolate differences in the in-plane vibrations that are not accessible to resonance Raman studies. The in-plane vibrations are at lower frequency in the imidazolate derivatives; the doming mode shifts are inconclusive. The stiffness, an experimentally determined force constant that averages the vibrational details to quantify the nearest-neighbor interactions, confirms that deprotonation inverts the relative strengths of axial and equatorial coordination.
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Affiliation(s)
- Chuanjiang Hu
- Contribution from Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P.R. China, Soochow University
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, University of Notre Dame
| | - Qian Peng
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, University of Notre Dame
| | - Nathan J. Silvernail
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, University of Notre Dame
| | - Alexander Barabanschikov
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, Northeastern University
| | - Jiyong Zhao
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, Argonne National Laboratory
| | - E. Ercan Alp
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, Argonne National Laboratory
| | - Wolfgang Sturhahn
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, Argonne National Laboratory
| | - J. Timothy Sage
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, Northeastern University
| | - W. Robert Scheidt
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, University of Notre Dame
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25
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Hu C, Barabanschikov A, Ellison MK, Zhao J, Alp EE, Sturhahn W, Zgierski MZ, Sage JT, Scheidt WR. Nuclear resonance vibrational spectra of five-coordinate imidazole-ligated iron(II) porphyrinates. Inorg Chem 2012; 51:1359-70. [PMID: 22243131 PMCID: PMC3273671 DOI: 10.1021/ic201580v] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nuclear resonance vibrational spectra have been obtained for six five-coordinate imidazole-ligated iron(II) porphyrinates, [Fe(Por)(L)] (Por = tetraphenylporphyrinate, octaethylporphyrinate, tetratolylporphyrinate, or protoporphyrinate IX and L = 2-methylimidazole or 1,2-dimethylimidazole). Measurements have been made on both powder and oriented crystal samples. The spectra are dominated by strong signals around 200-300 cm(-1). Although the in-plane and out-of-plane vibrations are seriously overlapped, oriented crystal spectra allow their deconvolution. Thus, oriented crystal experimental data, along with density functional theory (DFT) calculations, enable the assignment of key vibrations in the spectra. Molecular dynamics are also discussed. The nature of the Fe-N(Im) vibrations has been elaborated further than was possible from resonance Raman studies. Our study suggests that the Fe motions are coupled with the porphyrin core and peripheral groups motions. Both peripheral groups and their conformations have significant influence on the vibrational spectra (position and shape).
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Affiliation(s)
- Chuanjiang Hu
- Contribution from Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P.R. China
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Alexander Barabanschikov
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115
| | - Mary K. Ellison
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Jiyong Zhao
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439
| | - E. Ercan Alp
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439
| | - Wolfgang Sturhahn
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439
| | - Marek Z. Zgierski
- Steacie Institute for Molecular Science, National Research Council of Canada, Ottawa, Ontario, Canada KIA OR6
| | - J. Timothy Sage
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115
| | - W. Robert Scheidt
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
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26
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Larsen RW. Sub-nanosecond photolysis studies of Fe2+ protoporphyrin IX solubilized in neat dimethyl sulfoxide. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.01.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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27
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Hu C, Noll BC, Schulz CE, Scheidt WR. Electronic configuration of five-coordinate high-spin pyrazole-ligated iron(II) porphyrinates. Inorg Chem 2010; 49:10984-91. [PMID: 21047081 PMCID: PMC2993868 DOI: 10.1021/ic101469e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pyrazole, a neutral nitrogen ligand and an isomer of imidazole, has been used as a fifth ligand to prepare two new species, [Fe(TPP)(Hdmpz)] and [Fe(Tp-OCH(3)PP)(Hdmpz)] (Hdmpz = 3,5-dimethylpyrazole), the first structurally characterized examples of five-coordinate iron(II) porphyrinates with a nonimidazole neutral ligand. Both complexes are characterized by X-ray crystallography, and structures show common features for five-coordinate iron(II) species, such as an expanded porphyrinato core, large equatorial Fe-N(p) bond distances, and a significant out-of-plane displacement of the iron(II) atom. The Fe-N(pyrazole) and Fe-N(p) bond distances are similar to those in imidazole-ligated species. These suggest that the coordination abilities to iron(II) for imidazole and pyrazole are very similar even though pyrazole is less basic than imidazole. Mössbauer studies reveal that [Fe(TPP)(Hdmpz)] has the same behavior as those of imidazole-ligated species, such as negative quadrupole splitting values and relative large asymmetry parameters. Both the structures and the Mössbauer spectra suggest pyrazole-ligated five-coordinate iron(II) porphyrinates have the same electronic configuration as imidazole-ligated species.
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28
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Hijazi I, Roisnel T, Even-Hernandez P, Geneste F, Cador O, Guizouarn T, Boitrel B. Structural characterization of zinc and iron (II/III) complexes of a porphyrin bearing two built-in nitrogen bases. An example of high-spin diaqua-iron(III) bromo complex. Inorg Chem 2010; 49:7536-44. [PMID: 20690763 DOI: 10.1021/ic1009384] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A bis-strapped porphyrin with two intramolecular nitrogen bases was synthesized, and its zinc(II), iron(II), and iron(III) complexes have been structurally characterized. Whereas the zinc(II) complex is square pyramidal five-coordinate and the iron(II) complex is six-coordinate despite a significant distortion of the macrocycle induced by the rigidity of the straps, the iron(III) complex exhibits a peculiar bis-aqua structure in which no intramolecular axial base is bound to the iron atom in the porphyrin. Furthermore, on one side, the bromide counteranion of the iron is bound inside the cycle formed by a strap and establishes a hydrogen bond with an axially bound water molecule. On the other side, a residual HBr molecule protonates one pyridine base leading to the formation of an intermolecular pyridinium-pyridine hydrogen bond. The large ionic radius of the high-spin iron(III) cation is accommodated in the macrocycle with no displacement of the metal out of the mean porphyrinic plane, with an average Fe-Np bond distance of 2.057 A, and the axial Fe-Ow(aqua) bond distance measured at 2.090 A. As a result, this high-spin iron(III) bis-aqua complex is only lightly distorted.
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Affiliation(s)
- Ismail Hijazi
- Université de Rennes1, Sciences Chimiques de Rennes, UMR CNRS 6226, 35042 Rennes Cedex, France
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Li J, Noll BC, Oliver AG, Ferraudi G, Lappin AG, Scheidt WR. Oxygenation of cobalt porphyrinates: coordination or oxidation? Inorg Chem 2010; 49:2398-406. [PMID: 20104874 DOI: 10.1021/ic902309f] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The X-ray characterization of the five-coordinate picket-fence porphyrin complex, [Co(TpivPP)(2-MeHIm)], is reported. The complex has the displacement of cobalt from the porphyrin plane = 0.15 A, and Co-N(Im) = 2.145(3) and (Co-N(p))(av) = 1.979(3) A. This five-coordinate complex, in the presence of dioxygen and excess 2-methylimidazole, undergoes an unanticipated, photoinitiated atropisomerization of the porphyrin ligand, oxidation of cobalt(II), and the formation of the neutral cobalt(III) complex [Co(alpha,alpha,beta,beta-TpivPP)(2-MeHIm)(2-MeIm(-)]. Two distinct examples of this complex have been structurally characterized, and both have structural parameters consistent with cobalt(III). The two new Co(III) porphyrin complexes have axial Co-N(Im) distances ranging from 1.952 to 1.972 A, but which allow for the distinction between imidazole and imidazolate. An interesting intermolecular hydrogen bonding network is observed that leads to infinite helical chains. UV-vis spectroscopic study suggests that [Co(TpivPP)(2-MeHIm)(O(2))] is an intermediate state for the oxidation reaction and that the atropisomerization process is photocatalyzed. A reaction route is proposed based on the spectroscopic studies.
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Affiliation(s)
- Jianfeng Li
- The Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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30
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Hu C, Sulok CD, Paulat F, Lehnert N, Twigg AI, Hendrich MP, Schulz CE, Scheidt WR. Just a proton: distinguishing the two electronic states of five-coordinate high-spin iron(II) porphyrinates with imidazole/ate coordination. J Am Chem Soc 2010; 132:3737-50. [PMID: 20192189 PMCID: PMC2846462 DOI: 10.1021/ja907584x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report detailed studies on two S = 2 electronic states of high-spin iron(II) porphyrinates. These two states are exemplified by the five-coordinate derivatives with either neutral imidazole or anionic imidazolate as the axial ligand. The application of several physical methods all demonstrate distinctive differences between the two states. These include characteristic molecular structure differences, Mossbauer spectra, magnetic circular dichroism spectroscopy, and integer-spin EPR spectral distinctions. These distinctions are supported by DFT calculations. The two states are characterized by very different spatial properties of the doubly occupied orbital of the high-spin that are consonant with the physical properties.
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Affiliation(s)
| | | | | | - Nicolai Lehnert
- To whom correspondence should be addressed. (WRS), (NL, (MPH), “Charles E. Schulz” ¡¿ (CES)
| | | | - Michael P. Hendrich
- To whom correspondence should be addressed. (WRS), (NL, (MPH), “Charles E. Schulz” ¡¿ (CES)
| | - Charles E. Schulz
- To whom correspondence should be addressed. (WRS), (NL, (MPH), “Charles E. Schulz” ¡¿ (CES)
| | - W. Robert Scheidt
- To whom correspondence should be addressed. (WRS), (NL, (MPH), “Charles E. Schulz” ¡¿ (CES)
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31
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Pavlik JW, Noll BC, Oliver AG, Schulz CE, Scheidt WR. Hydrosulfide (HS-) coordination in iron porphyrinates. Inorg Chem 2010; 49:1017-26. [PMID: 20038134 PMCID: PMC2811220 DOI: 10.1021/ic901853p] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent reports of potential physiological roles of hydrogen sulfide have prompted interest in heme-sulfide interactions. Heme-H(2)S and/or heme-HS(-) interactions could potentially occur during endogenous production, transport, signaling events, and catabolism of H(2)S. We have investigated the interaction of the hydrosulfide ion (HS(-)) with iron porphyrinates. UV-vis spectral studies show the formation of [Fe(Por)(SH)](-), [Fe(Por)(SH)(2)](2-), and the mixed-ligand species [Fe(Por)(Im)(SH)](-). UV-vis binding studies of [Fe(OEP)] and [Fe(T-p-OMePP)] (OEP = octaethylporphyrinate; T-p-OMePP = tetra-p-methoxyphenylporphyrinate) with HS(-) allowed for calculation of the formation constants and extinction coefficients of mono- and bis-HS(-) complexes. We report the synthesis of the first HS(-)-bound iron(II) porphyrin compounds, [Na(222)][Fe(OEP)(SH)].0.5C(6)H(6) and [Na(222)][Fe(T-p-OMePP)(SH)].C(6)H(5)Cl (222 = Kryptofix-222). Characterization by single-crystal X-ray analysis, mass spectrometry, and Mossbauer and IR spectroscopy is all consistent with that of known sulfur-bound high-spin iron(II) compounds. The Fe-S distances of 2.3929(5) and 2.3887(13) A are longer than all reported values of [Fe(II)(Por)(SR)](-) species. An analysis of the porphyrin nonplanarity for these derivatives and for all five-coordinate high-spin iron(II) porphyrinate derivatives with an axial anion ligand is presented. In our hands, attempts to synthesize iron(III) HS(-) derivatives led to iron(II) species.
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Affiliation(s)
- Jeffrey W. Pavlik
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Bruce C. Noll
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Allen G. Oliver
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | | | - W. Robert Scheidt
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
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32
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Rydberg P, Olsen L. The Accuracy of Geometries for Iron Porphyrin Complexes from Density Functional Theory. J Phys Chem A 2009; 113:11949-53. [DOI: 10.1021/jp9035716] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Patrik Rydberg
- Department of Medicinal Chemistry, Copenhagen University, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Lars Olsen
- Department of Medicinal Chemistry, Copenhagen University, Universitetsparken 2, DK-2100 Copenhagen, Denmark
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33
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Synthesis, molecular structure, and properties of six-coordinate iron(III) porphyrin, [OEPFe(Pz)2]ClO4. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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34
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Zhang Y, Fujisaki H, Straub JE. Direct evidence for mode-specific vibrational energy relaxation from quantum time-dependent perturbation theory. I. Five-coordinate ferrous iron porphyrin model. J Chem Phys 2009; 130:025102. [DOI: 10.1063/1.3055277] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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35
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Radoń M, Pierloot K. Binding of CO, NO, and O2 to Heme by Density Functional and Multireference ab Initio Calculations. J Phys Chem A 2008; 112:11824-32. [PMID: 18942804 DOI: 10.1021/jp806075b] [Citation(s) in RCA: 186] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mariusz Radoń
- Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Kraków, Poland
| | - Kristine Pierloot
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Heverlee-Leuven, Belgium
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Hu C, Noll BC, Schulz CE, Scheidt WR. Hydrogen bonding influence of 1,10-phenanthroline on five-coordinate high-spin imidazole-ligated iron(II) porphyrinates. Inorg Chem 2008; 47:8884-95. [PMID: 18783213 PMCID: PMC2630385 DOI: 10.1021/ic8009496] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The influence of a hydrogen bond to the coordinated imidazole on the geometric and electronic structure of iron has been further studied in new complexes of five-coordinate high-spin imidazole-ligated iron(II) porphyrinates. With 1,10-phenanthroline (1,10-phen) as the hydrogen-bond acceptor, several new octaethylporphyrin dianion (OEP) and meso-tetraphenylporphyrin dianion (TPP) derivatives have been synthesized and characterized by X-ray crystallography and Mössbauer spectroscopy. In all three new structures, the porphyrin molecules and 1,10-phenanthroline molecules have been found with a ratio of 1:1. All the porphyrin derivatives are five-coordinate 2-methylimidazole-ligated iron(II) species. 1,10-Phenanthroline is hydrogen bonded to the coordinated imidazole to form two unequal hydrogen bonds. The Fe-N p and Fe-N Im bond lengths and displacement of the iron atom out of the porphyrin plane are similar to those in imidazole-ligated species. Mössbauer measurements showed remarkable temperature dependence; the analysis of the data obtained in applied magnetic field for [Fe(OEP)(2-MeHIm)].(1,10-phen) gave a negative quadrupole splitting value and large asymmetry parameters. All the structural and Mössbauer properties suggest that these new hydrogen-bonded species have the same electronic configuration as imidazole-ligated species.
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Affiliation(s)
- Chuanjiang Hu
- The Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Bruce C. Noll
- The Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Charles E. Schulz
- Department of Physics, Knox College, Galesburg, Illinois 61401, E-mail:
| | - W. Robert Scheidt
- The Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
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Khvostichenko D, Choi A, Boulatov R. Density Functional Theory Calculations of the Lowest Energy Quintet and Triplet States of Model Hemes: Role of Functional, Basis Set, and Zero-Point Energy Corrections. J Phys Chem A 2008; 112:3700-11. [DOI: 10.1021/jp076979t] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Andrew Choi
- Department of Chemistry, University of Illinois, Urbana, Illinois 61801
| | - Roman Boulatov
- Department of Chemistry, University of Illinois, Urbana, Illinois 61801
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Hu C, Noll BC, Piccoli PMB, Schultz AJ, Schulz CE, Scheidt WR. Hydrogen bonding effects on the electronic configuration of five-coordinate high-spin iron(II) porphyrinates. J Am Chem Soc 2008; 130:3127-36. [PMID: 18271587 PMCID: PMC2538548 DOI: 10.1021/ja078222l] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The characterization of a new five-coordinate derivative of (2-methylimidazole)(tetraphenylporphinato)iron(II) provides new and unique information about the effects of forming a hydrogen bond to the coordinated imidazole on the geometric and electronic structure of iron in these species. The complex studied has two crystallographically distinct iron sites; one site has an axial imidazole ligand modified by an external hydrogen bond, and the other site has an axial imidazole ligand with no external interactions. The iron atoms at the two sites have distinct geometric features, as revealed in their molecular structures, and distinct electronic structures, as shown by Mössbauer spectroscopy, although both are high spin (S = 2). The molecule with the external hydrogen bond has longer equatorial Fe-N(p) bonds, a larger displacement of the iron atom out of the porphyrin plane, and a shorter axial bond compared to its counterpart with no hydrogen bonding. The Mössbauer features are distinct for the two sites, with differing quadrupole splitting and isomer shift values and probably differing signs for the quadrupole splitting as shown by variable-temperature measurements in applied magnetic field. These features are consistent with a significant change in the nature of the doubly populated d orbital and are all in the direction of the dichotomy displayed by related imidazole and imidazolate species where deprotonation leads to major differences. The results points out the possible effects of strong hydrogen bonding in heme proteins.
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Affiliation(s)
- Chuanjiang Hu
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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39
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Yang QZ, Khvostichenko D, Atkinson JD, Boulatov R. Simple dimer containing dissociatively stable mono-imidazole ligated ferrohemes. Chem Commun (Camb) 2008:963-5. [DOI: 10.1039/b717858a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Scheidt WR. Explorations in metalloporphyrin stereochemistry, physical properties and beyond. J PORPHYR PHTHALOCYA 2008; 12:979-992. [PMID: 20198111 PMCID: PMC2829777 DOI: 10.1142/s1088424608000364] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A review of selected portions of our work in the area of porphyrin structure and physical characterization is presented. Topics covered include early work on periodic trends in first row transtion metalloporphyrins, a survey of electronic structure of iron derivatives including spin-state trends, ligand orientation effects and the elucidtion of unusual low-spin states for iron(II). A discussion of the different tlypes of high-spin iron(II) complexes and the effects of hydrogen bonding is given. A survey of nitric oxide (NO) derivatives is presented as well as a brief introduction into the use of nuclear resonance vibrational spectroscopy for the study of iron porphyrins and heme proteins.
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Affiliation(s)
- W Robert Scheidt
- Department of Chemistry and Biochemistry, 251 Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, USA
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41
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Leu BM, Silvernail NJ, Zgierski MZ, Wyllie GRA, Ellison MK, Scheidt WR, Zhao J, Sturhahn W, Alp EE, Sage JT. Quantitative vibrational dynamics of iron in carbonyl porphyrins. Biophys J 2007; 92:3764-83. [PMID: 17350996 PMCID: PMC1868970 DOI: 10.1529/biophysj.106.093773] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We use nuclear resonance vibrational spectroscopy and computational predictions based on density functional theory (DFT) to explore the vibrational dynamics of (57)Fe in porphyrins that mimic the active sites of histidine-ligated heme proteins complexed with carbon monoxide. Nuclear resonance vibrational spectroscopy yields the complete vibrational spectrum of a Mössbauer isotope, and provides a valuable probe that is not only selective for protein active sites but quantifies the mean-squared amplitude and direction of the motion of the probe nucleus, in addition to vibrational frequencies. Quantitative comparison of the experimental results with DFT calculations provides a detailed, rigorous test of the vibrational predictions, which in turn provide a reliable description of the observed vibrational features. In addition to the well-studied stretching vibration of the Fe-CO bond, vibrations involving the Fe-imidazole bond, and the Fe-N(pyr) bonds to the pyrrole nitrogens of the porphyrin contribute prominently to the observed experimental signal. All of these frequencies show structural sensitivity to the corresponding bond lengths, but previous studies have failed to identify the latter vibrations, presumably because the coupling to the electronic excitation is too small in resonance Raman measurements. We also observe the FeCO bending vibrations, which are not Raman active for these unhindered model compounds. The observed Fe amplitude is strongly inconsistent with three-body oscillator descriptions of the FeCO fragment, but agrees quantitatively with DFT predictions. Over the past decade, quantum chemical calculations have suggested revised estimates of the importance of steric distortion of the bound CO in preventing poisoning of heme proteins by carbon monoxide. Quantitative agreement with the predicted frequency, amplitude, and direction of Fe motion for the FeCO bending vibrations provides direct experimental support for the quantum chemical description of the energetics of the FeCO unit.
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Affiliation(s)
- Bogdan M Leu
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts, USA
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