1
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Heppe N, Gallenkamp C, Paul S, Segura-Salas N, von Rhein N, Kaiser B, Jaegermann W, Jafari A, Sergueev I, Krewald V, Kramm UI. Substituent Effects in Iron Porphyrin Catalysts for the Hydrogen Evolution Reaction. Chemistry 2023; 29:e202202465. [PMID: 36301727 DOI: 10.1002/chem.202202465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/27/2022] [Accepted: 10/27/2022] [Indexed: 11/07/2022]
Abstract
For a future hydrogen economy, non-precious metal catalysts for the water splitting reactions are needed that can be implemented on a global scale. Metal-nitrogen-carbon (MNC) catalysts with active sites constituting a metal center with fourfold coordination of nitrogen (MN4 ) show promising performance, but an optimization rooted in structure-property relationships has been hampered by their low structural definition. Porphyrin model complexes are studied to transfer insights from well-defined molecules to MNC systems. This work combines experiment and theory to evaluate the influence of porphyrin substituents on the electronic and electrocatalytic properties of MN4 centers with respect to the hydrogen evolution reaction (HER) in aqueous electrolyte. We found that the choice of substituent affects their utilization on the carbon support and their electrocatalytic performance. We propose an HER mechanism for supported iron porphyrin complexes involving a [FeII (P⋅)]- radical anion intermediate, in which a porphinic nitrogen atom acts as an internal base. While this work focuses on the HER, the limited influence of a simultaneous interaction with the support and an aqueous electrolyte will likely be transferrable to other catalytic applications.
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Affiliation(s)
- Nils Heppe
- Catalysts and Electrocatalysts, Department of Chemistry, Eduard-Zintl-Insitute for Inorganic and Physical Chemistry, Technical University Darmstadt, Otto-Berndt-Str. 3, 64287, Darmstadt, Germany
| | - Charlotte Gallenkamp
- Catalysts and Electrocatalysts, Department of Chemistry, Eduard-Zintl-Insitute for Inorganic and Physical Chemistry, Technical University Darmstadt, Otto-Berndt-Str. 3, 64287, Darmstadt, Germany.,Department of Chemistry, Theoretical Chemistry, Technical University Darmstadt, Alarich-Weiss-Str. 4, 64287, Darmstadt, Germany
| | - Stephen Paul
- Catalysts and Electrocatalysts, Department of Chemistry, Eduard-Zintl-Insitute for Inorganic and Physical Chemistry, Technical University Darmstadt, Otto-Berndt-Str. 3, 64287, Darmstadt, Germany
| | - Nicole Segura-Salas
- Catalysts and Electrocatalysts, Department of Chemistry, Eduard-Zintl-Insitute for Inorganic and Physical Chemistry, Technical University Darmstadt, Otto-Berndt-Str. 3, 64287, Darmstadt, Germany
| | - Niklas von Rhein
- Department of Chemistry, Theoretical Chemistry, Technical University Darmstadt, Alarich-Weiss-Str. 4, 64287, Darmstadt, Germany
| | - Bernhard Kaiser
- Institute of Materials Science, Surface Science Division, Technical University Darmstadt, Otto-Berndt-Str. 3, 64287, Darmstadt, Germany
| | - Wolfram Jaegermann
- Institute of Materials Science, Surface Science Division, Technical University Darmstadt, Otto-Berndt-Str. 3, 64287, Darmstadt, Germany
| | - Atefeh Jafari
- Deutsches Elektronen-Synchrotron, Notkestraße 85, 22607, Hamburg, Germany
| | - Ilya Sergueev
- Deutsches Elektronen-Synchrotron, Notkestraße 85, 22607, Hamburg, Germany
| | - Vera Krewald
- Department of Chemistry, Theoretical Chemistry, Technical University Darmstadt, Alarich-Weiss-Str. 4, 64287, Darmstadt, Germany
| | - Ulrike I Kramm
- Catalysts and Electrocatalysts, Department of Chemistry, Eduard-Zintl-Insitute for Inorganic and Physical Chemistry, Technical University Darmstadt, Otto-Berndt-Str. 3, 64287, Darmstadt, Germany
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2
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Miller NA, Michocki LB, Konar A, Alonso-Mori R, Deb A, Glownia JM, Sofferman DL, Song S, Kozlowski PM, Kubarych KJ, Penner-Hahn JE, Sension RJ. Ultrafast XANES Monitors Femtosecond Sequential Structural Evolution in Photoexcited Coenzyme B 12. J Phys Chem B 2020; 124:199-209. [PMID: 31850761 DOI: 10.1021/acs.jpcb.9b09286] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Polarized X-ray absorption near-edge structure (XANES) at the Co K-edge and broadband UV-vis transient absorption are used to monitor the sequential evolution of the excited-state structure of coenzyme B12 (adenosylcobalamin) over the first picosecond following excitation. The initial state is characterized by sub-100 fs sequential changes around the central cobalt. These are polarized first in the y-direction orthogonal to the transition dipole and 50 fs later in the x-direction along the transition dipole. Expansion of the axial bonds follows on a ca. 200 fs time scale as the molecule moves out of the Franck-Condon active region of the potential energy surface. On the same 200 fs time scale there are electronic changes that result in the loss of stimulated emission and the appearance of a strong absorption at 340 nm. These measurements provide a cobalt-centered movie of the excited molecule as it evolves to the local excited-state minimum.
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Affiliation(s)
- Nicholas A Miller
- Department of Chemistry , University of Michigan , 930 N. University Ave. , Ann Arbor , Michigan 48109-1055 , United States
| | - Lindsay B Michocki
- Department of Chemistry , University of Michigan , 930 N. University Ave. , Ann Arbor , Michigan 48109-1055 , United States
| | - Arkaprabha Konar
- Department of Physics , University of Michigan , 450 Church Street , Ann Arbor , Michigan 48109-1040 , United States
| | - Roberto Alonso-Mori
- Linac Coherent Light Source , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - Aniruddha Deb
- Department of Chemistry , University of Michigan , 930 N. University Ave. , Ann Arbor , Michigan 48109-1055 , United States.,Department of Biophysics , University of Michigan , 930 N. University Ave. , Ann Arbor , Michigan 48109-1055 , United States
| | - James M Glownia
- Linac Coherent Light Source , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - Danielle L Sofferman
- Program in Applied Physics , University of Michigan , 450 Church Street , Ann Arbor , Michigan 48109-1040 , United States
| | - Sanghoon Song
- Linac Coherent Light Source , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - Pawel M Kozlowski
- Department of Chemistry , University of Louisville , 2320 South Brook Street , Louisville , Kentucky 40292 , United States
| | - Kevin J Kubarych
- Department of Chemistry , University of Michigan , 930 N. University Ave. , Ann Arbor , Michigan 48109-1055 , United States.,Department of Biophysics , University of Michigan , 930 N. University Ave. , Ann Arbor , Michigan 48109-1055 , United States
| | - James E Penner-Hahn
- Department of Chemistry , University of Michigan , 930 N. University Ave. , Ann Arbor , Michigan 48109-1055 , United States.,Department of Biophysics , University of Michigan , 930 N. University Ave. , Ann Arbor , Michigan 48109-1055 , United States
| | - Roseanne J Sension
- Department of Chemistry , University of Michigan , 930 N. University Ave. , Ann Arbor , Michigan 48109-1055 , United States.,Department of Physics , University of Michigan , 450 Church Street , Ann Arbor , Michigan 48109-1040 , United States.,Department of Biophysics , University of Michigan , 930 N. University Ave. , Ann Arbor , Michigan 48109-1055 , United States
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3
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Peng Q, Sage JT, Liu Y, Wang Z, Hu MY, Zhao J, Alp EE, Scheidt WR, Li J. How Does a Heme Carbene Differ from Diatomic Ligated (NO, CO, and CN -) Analogues in the Axial Bond? Inorg Chem 2018; 57:8788-8795. [PMID: 30010336 DOI: 10.1021/acs.inorgchem.8b00574] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Compared to well studied diatomic ligands (NO, CN-, CO), the axial bonds of carbene hemes is much less known although its significance in biological chemistry. The unusually large quadrupole splitting (Δ EQ = +2.2 mm·s-1) and asymmetric parameter (η = 0.9) of the five-coordinate heme carbene [Fe(TTP)(CCl2)], which is the largest among all known low spin ferrohemes, has driven investigations by means of Mössbauer effect Nuclear Resonance Vibrational Spectroscopy (NRVS). Three distinct measurements on one single crystal (two in-plane and one out-of-plane) have demonstrated comprehensive vibrational structures including stretch (429) and bending modes (472 cm-1) of the axial Fe-CCl2, and revealed iron vibrational anisotropy in three orthogonal directions for the first time. Frontier orbital analysis especially comparisons with diatomic analogues (NO, CN-, CO) suggest that CCl2, similar to NO, has led to strong but anisotropic π bonding in a ligand-based "4C"-coordinate which induced the vibrational anisotropies and very large Mössbauer parameters. This is contrasted to CN- and CO complexes which possess a porphyrin-based "4N"-coordinate electronic and vibrational structures due to inherent on-axis linear ligation.
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Affiliation(s)
- Qian Peng
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - J Timothy Sage
- Department of Physics and Center for Interdisciplinary Research on Complex Systems , Northeastern University , Boston , Massachusetts 02115 , United States
| | - Yulong Liu
- College of Materials Science and Optoelectronic Technology , University of Chinese Academy of Sciences , Yanqi Lake, Huairou, Beijing 101408 , China
| | - Zijian Wang
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Michael Y Hu
- Advanced Photon Source , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Jiyong Zhao
- Advanced Photon Source , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - E Ercan Alp
- Advanced Photon Source , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - 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, Beijing 101408 , China
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4
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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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5
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Usman M, Zaki M, Khan RA, Alsalme A, Ahmad M, Tabassum S. Coumarin centered copper( ii) complex with appended-imidazole as cancer chemotherapeutic agents against lung cancer: molecular insight via DFT-based vibrational analysis. RSC Adv 2017; 7:36056-36071. [DOI: 10.1039/c7ra05874h] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023] Open
Abstract
Synthesis and structural characterization of the novel copper complex, DFT based vibrational analysis, DNA binding studies. In vitro cytotoxicity against A549 cancer cell lines and estimation of GSH, ROS, LPO levels, have been reported.
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Affiliation(s)
- Mohammad Usman
- Department of Chemistry
- Aligarh Muslim University
- Aligarh – 202002
- India
| | - Mehvash Zaki
- Department of Chemistry
- Aligarh Muslim University
- Aligarh – 202002
- India
| | - Rais Ahmad Khan
- Department of Chemistry
- College of Science
- King Saud University
- Riyadh 11451
- Kingdom of Saudi Arabia
| | - Ali Alsalme
- Department of Chemistry
- College of Science
- King Saud University
- Riyadh 11451
- Kingdom of Saudi Arabia
| | - Musheer Ahmad
- Department of Applied Chemistry
- Aligarh Muslim University
- Aligarh – 202002
- India
| | - Sartaj Tabassum
- Department of Chemistry
- Aligarh Muslim University
- Aligarh – 202002
- India
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6
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Arjmand F, Sharma S, Usman M, Leu BM, Hu MY, Toupet L, Gosztola D, Tabassum S. Vibrational dynamics (IR, Raman, NRVS) and a DFT study of a new antitumor tetranuclearstannoxane cluster, Sn(iv)-oxo-{di-o-vanillin} dimethyl dichloride. Phys Chem Chem Phys 2016; 18:17805-17809. [PMID: 27328161 DOI: 10.1039/c6cp02914k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
The vibrational dynamics of a newly synthesized tetrastannoxane was characterized with a combination of experimental (Raman, IR and tin-based nuclear resonance vibrational spectroscopy) and computational (DFT/B3LYP) methods, with an emphasis on the vibrations of the tin sites. The cytotoxic activity revealed a significant regression selectively against the human pancreatic cell lines.
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Affiliation(s)
- F Arjmand
- Department of Chemistry, Aligarh Muslim University, Aligarh 202002, India.
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7
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Berto TC, Xu N, Lee SR, McNeil AJ, Alp EE, Zhao J, Richter-Addo GB, Lehnert N. Characterization of the Bridged Hyponitrite Complex {[Fe(OEP)]2(μ-N2O2)}: Reactivity of Hyponitrite Complexes and Biological Relevance. Inorg Chem 2014; 53:6398-414. [DOI: 10.1021/ic5002573] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Timothy C. Berto
- Department
of Chemistry and Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Nan Xu
- Department
of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson
Parkway, Norman, Oklahoma 73019, United States
| | - Se Ryeon Lee
- Department
of Chemistry and Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Anne J. McNeil
- Department
of Chemistry and Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - E. Ercan Alp
- Argonne National Laboratory, APS/XFD, 431/D003, Argonne, Illinois 60439, United States
| | - Jiyong Zhao
- Argonne National Laboratory, APS/XFD, 431/D003, Argonne, Illinois 60439, United States
| | - George B. Richter-Addo
- Department
of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson
Parkway, Norman, Oklahoma 73019, United States
| | - Nicolai Lehnert
- Department
of Chemistry and Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
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8
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Pavlik J, Peng Q, Silvernail N, Alp EE, Hu MY, Zhao J, Sage JT, Scheidt WR. Anisotropic iron motion in nitrosyl iron porphyrinates: natural and synthetic hemes. Inorg Chem 2014; 53:2582-90. [PMID: 24528178 PMCID: PMC3993889 DOI: 10.1021/ic4028964] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Indexed: 02/05/2023]
Abstract
The vibrational spectra of two five-coordinate nitrosyl iron porphyrinates, [Fe(OEP)(NO)] (OEP = dianion of 2,3,7,8,12,13,17,18-octaethylporphyrin) and [Fe(DPIX)(NO)] (DPIX = deuteroporphyrin IX), have been studied by oriented single-crystal nuclear resonance vibrational spectroscopy. Single crystals (both are in the triclinic crystal system) were oriented to give vibrational spectra perpendicular to the porphyrin plane. Additionally, two orthogonal in-plane measurements that were also either perpendicular or parallel to the projection of the FeNO plane onto the porphyrin plane yield the complete set of vibrations with iron motion. In addition to cleanly enabling the assignment of the FeNO bending and stretching modes, the measurements reveal that the two in-plane spectra from the parallel and perpendicular in-plane directions for both compounds have substantial differences. The assignment of these in-plane vibrations were aided by density functional theory predictions. The differences in the two in-plane directions result from the strongly bonded axial NO ligand. The direction of the in-plane iron motion is thus found to be largely parallel and perpendicular to the projection of the FeNO plane on the porphyrin plane. These axial ligand effects on the in-plane iron motion are related to the strength of the axial ligand-to-iron bond.
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Affiliation(s)
- Jeffrey
W. Pavlik
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Qian Peng
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Nathan
J. Silvernail
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre Dame, Indiana 46556, United States
| | - E. Ercan Alp
- Advanced
Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Michael Y. Hu
- Advanced
Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Jiyong Zhao
- Advanced
Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - J. Timothy Sage
- Department
of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, 120 Forsyth Street, Boston, Massachusetts 02115, United States
| | - W. Robert Scheidt
- Department
of Chemistry and Biochemistry, University
of Notre Dame, Notre Dame, Indiana 46556, United States
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9
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Thompson LM, Lasoroski A, Champion PM, Sage JT, Frisch MJ, van Thor JJ, Bearpark MJ. Analytical Harmonic Vibrational Frequencies for the Green Fluorescent Protein Computed with ONIOM: Chromophore Mode Character and Its Response to Environment. J Chem Theory Comput 2014; 10:751-66. [DOI: 10.1021/ct400664p] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Lee M. Thompson
- Department
of Chemistry, Imperial College, London SW7 2AZ, United Kingdom
| | - Aurélie Lasoroski
- Department
of Chemistry, Imperial College, London SW7 2AZ, United Kingdom
- Ecole Normale
Supérieure, Département de Chimie, ENS-CNRS-UPMC UMR8640, 75005 Paris, France
| | - Paul M. Champion
- Department
of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, United States
| | - J. Timothy Sage
- Department
of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, United States
| | - Michael J. Frisch
- Gaussian, Inc., 340 Quinnipiac Street, Building 40, Wallingford, Connecticut 06492, United States
| | - Jasper J. van Thor
- Division
of Molecular Biosciences, Imperial College, London SW7 2AZ, United Kingdom
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10
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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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11
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Leu BM, Zgierski MZ, Bischoff C, Li M, Hu MY, Zhao J, Martin SW, Alp EE, Scheidt WR. Quantitative vibrational dynamics of the metal site in a tin porphyrin: an IR, NRVS, and DFT study. Inorg Chem 2013; 52:9948-53. [PMID: 23962374 PMCID: PMC3787516 DOI: 10.1021/ic401152b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We used a newer, synchrotron-based, spectroscopic technique (nuclear resonance vibrational spectroscopy, NRVS) in combination with a more traditional one (infrared absorption, IR) to obtain a complete, quantitative picture of the metal center vibrational dynamics in a six-coordinated tin porphyrin. From the NRVS (119)Sn site-selectivity and the sensitivity of the IR signal to (112)Sn/(119)Sn isotope substitution, we identified the frequency of the antisymmetric stretching of the axial bonds (290 cm(-1)) and all the other vibrations involving Sn. Experimentally authenticated density functional theory (DFT) calculations aid the data interpretation by providing detailed normal mode descriptions for each observed vibration. These results may represent a starting point toward the characterization of the local vibrational dynamics of the metallic site in tin porphyrins and compounds with related structures. The quantitative complementariness between IR, NRVS, and DFT is emphasized.
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Affiliation(s)
- Bogdan M Leu
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States.
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12
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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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13
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Li J, Peng Q, Barabanschikov A, Pavlik JW, Alp EE, Sturhahn W, Zhao J, Sage JT, Scheidt WR. Vibrational probes and determinants of the S = 0 ⇌ S = 2 spin crossover in five-coordinate [Fe(TPP)(CN)]-. Inorg Chem 2012; 51:11769-78. [PMID: 23082814 PMCID: PMC3498855 DOI: 10.1021/ic301719v] [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: 11/28/2022]
Abstract
The low-frequency vibrational characterization of the spin-crossover complex, five-coordinate cyano(tetraphenylporphyrinato)iron(II), [Fe(TPP)(CN)](-), is reported. Nuclear resonance vibrational spectroscopy has been used to measure all low-frequency vibrations involving iron at several temperatures; this yields vibrational spectra of both the low- (S = 0) and high-spin (S = 2) states. Multitemperature oriented single-crystal measurements facilitate assignments of the vibrational character of all modes and are consistent with the DFT-predicted spectra. The availability of the entire iron vibrational spectrum allows for the complete correlation of the modes between the two spin states. These data demonstrate that not only do the frequencies of the vibrations shift to lower values for the high-spin species as would be expected owing to the weaker bonds in the high-spin state, but also the mixing of iron modes with ligand modes changes substantially. Diagrams illustrating the changing character of the modes and their correlation are given. The reduced iron-ligand frequencies are the primary factor in the entropic stabilization of the high-spin state responsible for the spin crossover.
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Affiliation(s)
- Jianfeng Li
- To whom correspondence should be addressed. JL: , JTS: , WRS:
| | | | | | | | | | | | | | - J. Timothy Sage
- To whom correspondence should be addressed. JL: , JTS: , WRS:
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Zeng W, Barabanschikov A, Wang N, Lu Y, Zhao J, Sturhahn W, Alp EE, Sage JT. Vibrational dynamics of oxygenated heme proteins. Chem Commun (Camb) 2012; 48:6340. [PMID: 22498848 DOI: 10.1039/c2cc31239e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Advanced spectroscopic techniques coupled with DFT calculations reveal the vibrational dynamics of the iron in stable dioxygen complexes with myoglobin and with a mutant engineered to model the catalytic site of heme-copper oxidases. The unprecedented level of detail will constrain computational modelling of reactions with oxygen.
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Affiliation(s)
- Weiqiao Zeng
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, BostonMA 02115, USA.
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15
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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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