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Tomita Y, Okamura T, Onitsuka K. One Ligand Fits All: Formation and Stabilization of a Single‐Ligand Arenethiolato Cobalt(II) Complex via Metal‐π Coordination from a Bulky Acylamino Group. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Yusuke Tomita
- Department of Macromolecular Science Graduate School of Science Osaka University Toyonaka Osaka 560-0043 Japan
| | - Taka‐aki Okamura
- Department of Macromolecular Science Graduate School of Science Osaka University Toyonaka Osaka 560-0043 Japan
| | - Kiyotaka Onitsuka
- Department of Macromolecular Science Graduate School of Science Osaka University Toyonaka Osaka 560-0043 Japan
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2
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Pätsch S, Correia JV, Elvers BJ, Steuer M, Schulzke C. Inspired by Nature-Functional Analogues of Molybdenum and Tungsten-Dependent Oxidoreductases. Molecules 2022; 27:molecules27123695. [PMID: 35744820 PMCID: PMC9227248 DOI: 10.3390/molecules27123695] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 11/18/2022] Open
Abstract
Throughout the previous ten years many scientists took inspiration from natural molybdenum and tungsten-dependent oxidoreductases to build functional active site analogues. These studies not only led to an ever more detailed mechanistic understanding of the biological template, but also paved the way to atypical selectivity and activity, such as catalytic hydrogen evolution. This review is aimed at representing the last decade’s progress in the research of and with molybdenum and tungsten functional model compounds. The portrayed systems, organized according to their ability to facilitate typical and artificial enzyme reactions, comprise complexes with non-innocent dithiolene ligands, resembling molybdopterin, as well as entirely non-natural nitrogen, oxygen, and/or sulfur bearing chelating donor ligands. All model compounds receive individual attention, highlighting the specific novelty that each provides for our understanding of the enzymatic mechanisms, such as oxygen atom transfer and proton-coupled electron transfer, or that each presents for exploiting new and useful catalytic capability. Overall, a shift in the application of these model compounds towards uncommon reactions is noted, the latter are comprehensively discussed.
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3
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Boncella AE, Sabo ET, Santore RM, Carter J, Whalen J, Hudspeth JD, Morrison CN. The expanding utility of iron-sulfur clusters: Their functional roles in biology, synthetic small molecules, maquettes and artificial proteins, biomimetic materials, and therapeutic strategies. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214229] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Stoian SA, Moshari M, Ferentinos E, Grigoropoulos A, Krzystek J, Telser J, Kyritsis P. Electronic Structure of Tetrahedral, S = 2, [Fe{(EP iPr 2) 2N} 2], E = S, Se, Complexes: Investigation by High-Frequency and -Field Electron Paramagnetic Resonance, 57Fe Mössbauer Spectroscopy, and Quantum Chemical Studies. Inorg Chem 2021; 60:10990-11005. [PMID: 34288665 DOI: 10.1021/acs.inorgchem.1c00670] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work, we assessed the electronic structures of two pseudotetrahedral complexes of FeII, [Fe{(SPiPr2)2N}2] (1) and [Fe{(SePiPr2)2N}2] (2), using high-frequency and -field EPR (HFEPR) and field-dependent 57Fe Mössbauer spectroscopies. This investigation revealed S = 2 ground states characterized by moderate, negative zero-field splitting (zfs) parameters D. The crystal-field (CF) theory analysis of the spin Hamiltonian (sH) and hyperfine structure parameters revealed that the orbital ground states of 1 and 2 have a predominant dx2-y2 character, which is admixed with dz2 (∼10%). Although replacing the S-containing ligands of 1 by their Se-containing analogues in 2 leads to a smaller |D| value, our theoretical analysis, which relied on extensive ab initio CASSCF calculations, suggests that the ligand spin-orbit coupling (SOC) plays a marginal role in determining the magnetic anisotropy of these compounds. Instead, the dx2-y2β → dxyβ excitations yield a large negative contribution, which dominates the zfs of both 1 and 2, while the different energies of the dx2-y2β → dxzβ transitions are the predominant factor responsible for the difference in zfs between 1 and 2. The electronic structures of these compounds are contrasted with those of other [FeS4] sites, including reduced rubredoxin by considering a D2-type distortion of the [Fe(E-X)4] cores, where E = S, Se; X = C, P. Our combined CASSCF/DFT calculations indicate that while the character of the orbital ground state and the quintet excited states' contribution to the zfs of 1 and 2 are modulated by the magnitude of the D2 distortion, this structural change does not impact the contribution of the excited triplet states.
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Affiliation(s)
- Sebastian A Stoian
- Department of Chemistry, University of Idaho, Moscow, Idaho 83844, United States
| | - Mahsa Moshari
- Department of Chemistry, University of Idaho, Moscow, Idaho 83844, United States
| | - Eleftherios Ferentinos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Zografou, 15771 Athens, Greece
| | - Alexios Grigoropoulos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Zografou, 15771 Athens, Greece
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Joshua Telser
- Department of Biological, Physical, and Health Sciences, Roosevelt University, Chicago, Illinois 60605, United States
| | - Panayotis Kyritsis
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Zografou, 15771 Athens, Greece
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5
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Scheurer M, Dreuw A, Head-Gordon M, Stauch T. The rupture mechanism of rubredoxin is more complex than previously thought. Chem Sci 2020; 11:6036-6044. [PMID: 34094096 PMCID: PMC8159389 DOI: 10.1039/d0sc02164d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The surprisingly low rupture force and remarkable mechanical anisotropy of rubredoxin have been known for several years. Exploiting the first combination of steered molecular dynamics and the quantum chemical Judgement of Energy DIstribution (JEDI) analysis, the common belief that hydrogen bonds between neighboring amino acid backbones and the sulfur atoms of the central FeS4 unit in rubredoxin determine the low mechanical resistance of the protein is invalidated. The distribution of strain energy in the central part of rubredoxin is elucidated in real-time with unprecedented detail, giving important insights into the mechanical unfolding pathway of rubredoxin. While structural anisotropy as well as the contribution of angle bendings in the FeS4 unit have a significant influence on the mechanical properties of rubredoxin, these factors are insufficient to explain the experimentally observed low rupture force. Instead, the rupture mechanism of rubredoxin is far more complex than previously thought and requires more than just a hydrogen bond network.
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Affiliation(s)
- Maximilian Scheurer
- Interdisciplinary Center for Scientific ComputingIm Neuenheimer Feld 20569120 HeidelbergGermany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific ComputingIm Neuenheimer Feld 20569120 HeidelbergGermany
| | - Martin Head-Gordon
- Department of Chemistry, University of CaliforniaBerkeleyCalifornia 94720USA,Chemical Sciences Division, Lawrence Berkeley National Laboratory, University of CaliforniaBerkeleyCalifornia 94720USA
| | - Tim Stauch
- University of Bremen, Institute for Physical and Theoretical ChemistryLeobener Straße NW2D-28359 BremenGermany,Bremen Center for Computational Materials Science, University of BremenAm Fallturm 1D-28359 BremenGermany,MAPEX Center for Materials and Processes, University of BremenBibliothekstraße 1D-28359 BremenGermany
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Liu X, Song H, Zhai X, Tung CH, Wang W. Cobalt-catalyzed regioselective hydrohydrazination of epoxides. Org Biomol Chem 2020; 18:1572-1576. [PMID: 32039418 DOI: 10.1039/d0ob00037j] [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
Using an air-stable cobalt catalyst [Cp*Co(1,2-Ph2PC6H4S)(NCMe)]BF4 (1, Cp* = Me5C5-), we have achieved catalytic regioselective hydrohydrazination of epoxides to 1,1-hydrazinoalcohols in an atom-economical manner. The catalysis involves a cobalt-hydrazine intermediate, in which the NH2 group of the hydrazine binds to the metal center, inhibiting its nucleophilic reactivity and allowing the NH group to participate in the regioselective hydrohydrazination.
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Affiliation(s)
- Xiangyu Liu
- Key Lab of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
| | - Heng Song
- School of Environment and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu, China
| | - Xiaofang Zhai
- Key Lab of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
| | - Chen-Ho Tung
- Key Lab of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
| | - Wenguang Wang
- Key Lab of Colloid and Interface Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
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Okamura TA, Tomita Y, Onitsuka K. Crystal-to-Crystal Isomerization via Drastic Intramolecular Ligand Exchange: Vapochromism of a Bis(arenethiolato)cobalt(II) Complex Containing Bulky Acylamino Groups. Inorg Chem 2020; 59:1164-1168. [PMID: 31891262 DOI: 10.1021/acs.inorgchem.9b02791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Crystal-to-crystal transitions normally avoid drastic configurational changes that result in loss of crystallinity. A cobalt(II) complex, containing two unsymmetrically disubstituted arenethiolato ligands with bulky acylamino (Ar3CCONH, Ar = 4-t-BuC6H4) and t-BuCONH groups, showed crystal-to-crystal configurational isomerization accompanied by vapochromism. Recrystallization using THF/n-hexane afforded green crystals (isomer G) containing one n-hexane molecule per asymmetric unit. In contrast, blue crystals (isomer B), containing two toluene molecules per unit, were obtained using a toluene solution. Isomer G contained S,O-chelates involving Ar3CCO carbonyl groups, while isomer B contained chelates involving t-BuCO groups. Upon exposure to toluene vapor, crystal isomer G was gradually converted to crystal isomer B, maintaining its crystallinity despite the drastic intramolecular ligand exchange. Although the blue coloration was due to an unfavorable, distorted, and stretched chemical structure, formation of strong intermolecular NH···O═C hydrogen bond chains counteracted this disadvantage. Therefore, blue crystal formation as a whole was thermodynamically favorable. The release of n-hexane from the green crystals initiated the isomerization and resulted in tightly packed blue crystals. The tense conformation of the blue crystals was facilely relaxed by cleaving the hydrogen bond chains through grinding and resulted in a green powder that maintained the original coordination of isomer B, which reverted easily to blue crystals upon exposure to toluene vapor.
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Affiliation(s)
- Taka-Aki Okamura
- Department of Macromolecular Science, Graduate School of Science , Osaka University , Toyonaka, Osaka 560-0043 , Japan
| | - Yusuke Tomita
- Department of Macromolecular Science, Graduate School of Science , Osaka University , Toyonaka, Osaka 560-0043 , Japan
| | - Kiyotaka Onitsuka
- Department of Macromolecular Science, Graduate School of Science , Osaka University , Toyonaka, Osaka 560-0043 , Japan
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8
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Chand A, Biswal HS. Hydrogen Bonds with Chalcogens: Looking Beyond the Second Row of the Periodic Table. J Indian Inst Sci 2019. [DOI: 10.1007/s41745-019-00140-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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9
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Halder P, Ghorai S, Banerjee S, Mondal B, Rana A. Iron(ii) complexes of 2-mercaptopyridine as rubredoxin site analogues. Dalton Trans 2018; 46:13739-13744. [PMID: 28956575 DOI: 10.1039/c7dt02645e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis, characterization and reactivity studies of iron(ii) complexes [FeII(PySH)4](OTf)2, 1-(OTf)2, [FeII(PySH)4](ClO)4, 1-(ClO4)2, and [FeII(PyS)2]n, (2), of a 2-mercaptopyridine (PySH) ligand are discussed. The X-ray crystal structures of both 1-(OTf)2 and 1-(ClO4)2 reveal a distorted tetrahedral geometry at the iron(ii) center with identical constituents. All the pyridine nitrogen atoms are protonated and thiolate ions are coordinated to the iron(ii) center. The structure and function of complex 1-(OTf)2 or 1-(ClO4)2 resembles the active site of rubredoxin. Complex 2 has octahedral geometry at the iron(ii) center forming a 1-D coordination polymer. Complex 1-(OTf)2 exhibits a high positive redox potential (E1/2 = 0.23 V vs. Ag/AgCl) which reduces to -0.12 V in the presence of triethylamine under an inert atmosphere. This change of the redox potential is highly reversible in the presence of a weak acid such as p-toluenesulfonic acid, pTsOH. DFT studies show that the complex cation [FeII(PySH)4]2+ upon treatment with a base converts to its anionic congener, [FeII(PyS)4]2-, via the deprotonation of the pyridinium moiety. The iron(ii) complexes readily react with molecular oxygen to yield the corresponding iron(iii) complex, which rapidly decays to form pyridine disulphide (Py2S2) and an iron(ii) complex.
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Affiliation(s)
- Partha Halder
- Department of Chemistry, Scottish Church College, 1 & 3 Urquhart Square, Kolkata-700006, India.
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Mishra KK, Singh SK, Ghosh P, Ghosh D, Das A. The nature of selenium hydrogen bonding: gas phase spectroscopy and quantum chemistry calculations. Phys Chem Chem Phys 2018; 19:24179-24187. [PMID: 28840208 DOI: 10.1039/c7cp05265k] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Subsequent to the recent re-definition of hydrogen bonding by the IUPAC committee, there has been a growing search for finding the presence of this ever interesting non-covalent interaction between a hydrogen atom in an X-H group and any other atom in the periodic table. In recent gas phase experiments, it has been observed that hydrogen bonding interactions involving S and Se are of similar strength to those with an O atom. However, there is no clear explanation for the unusual strength of this interaction in the case of hydrogen bond acceptors which are not conventional electronegative atoms. In this work, we have explored the nature of Se hydrogen bonding by studying indoledimethyl selenide (indmse) and phenoldimethyl selenide (phdmse) complexes using gas phase IR spectroscopy and quantum chemistry calculations. We have found through various energy decomposition analysis (EDA) methods and natural bond orbital (NBO) calculations that, along with electrostatics and polarization, charge transfer interactions are important to understand Se/S hydrogen bonding and there is a delicate balance between the various interactions that plays the crucial role rather than a single component of the interaction energy. An in-depth understanding of this type of non-covalent interaction has immense significance in biology as amino acids containing S and Se are widely present in proteins and hence hydrogen bonding interactions involving S and Se atoms contribute to the folding of proteins.
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Affiliation(s)
- Kamal K Mishra
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Dr Homi Bhabha Road, Pune-411008, India.
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11
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Okamura TA, Omi Y, Hirano Y, Onitsuka K. Comparative studies on the contribution of NHS hydrogen bonds in tungsten and molybdenum benzenedithiolate complexes. Dalton Trans 2018; 45:15651-15659. [PMID: 27722343 DOI: 10.1039/c6dt02250b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of monooxotungsten(iv) and dioxotungsten(vi) benzenedithiolates, (NEt4)2[WIVO(1,2-S2-3-RCONHC6H3)2] (1-W; R = CH3 (a), t-Bu (b), or CF3 (c)) and (NEt4)2[WVIO2(1,2-S2-3-RCONHC6H3)2] (2-W), were synthesized and compared with the corresponding molybdenum analogues. Single crystals of trans-1b-W were successfully obtained, and the crystal structure was determined by X-ray analysis although 1b-Mo could not be crystallized. The NHS hydrogen bonds shifted the potential of the W(iv/v) redox couple to more positive values, and the strength of the hydrogen bond and the positive shift value were strongly correlated. The hydrogen bonds in both 1-W and 2-W were weaker than those in the corresponding molybdenum analogues; however, the effect of the hydrogen bonds on the redox potential was greater in 1-W.
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Affiliation(s)
- Taka-Aki Okamura
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - Yui Omi
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - Yasunori Hirano
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - Kiyotaka Onitsuka
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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12
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Fataftah MS, Coste SC, Vlaisavljevich B, Zadrozny JM, Freedman DE. Transformation of the coordination complex [Co(C 3S 5) 2] 2- from a molecular magnet to a potential qubit. Chem Sci 2016; 7:6160-6166. [PMID: 30034755 PMCID: PMC6024178 DOI: 10.1039/c6sc02170k] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 06/09/2016] [Indexed: 12/25/2022] Open
Abstract
We employ ac susceptibility as a probe of small changes of transverse zero-field splitting, revealing that these subtle changes transform [Co(C3S5)2]2– from a molecular magnet to a candidate qubit.
Mononuclear transition metal complexes demonstrate significant potential in the divergent applications of spintronics and quantum information processing. The facile tunability of these complexes enables structure function correlations for a plethora of relevant magnetic quantities. We present a series of pseudotetrahedral [Co(C3S5)2]2– complexes with varying deviations from D2d symmetry to investigate the influence of structural distortions on spin relaxation dynamics and qubit viability, as tuned by the variable transverse magnetic anisotropy, E. To overcome the traditional challenge of measuring E in species where D ≫ E, we employed a different approach of harnessing ac magnetic susceptibility to probe the emergence of quantum tunneling of magnetization as a proxy for E. Across the range of values for E in the series, we observe magnetic hysteresis for the smallest value of E. The hysteresis disappears with increasing E, concomitant with the appearance of an observable, low frequency (L-band) electron paramagnetic resonance (EPR) signal, indicating the potential to controllably shift the molecule's utilization from classical to quantum information processing applications. The development of design principles for molecular magnet information processing requires separate design principles for classical versus quantum regimes. Here we show for the first time how subtle structural changes can switch the utility of a complex between these two types of applications.
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Affiliation(s)
- Majed S Fataftah
- Department of Chemistry , Northwestern University , Evanston , IL 60208 , USA .
| | - Scott C Coste
- Department of Chemistry , Northwestern University , Evanston , IL 60208 , USA .
| | - Bess Vlaisavljevich
- Department of Chemistry , Northwestern University , Evanston , IL 60208 , USA .
| | - Joseph M Zadrozny
- Department of Chemistry , Northwestern University , Evanston , IL 60208 , USA .
| | - Danna E Freedman
- Department of Chemistry , Northwestern University , Evanston , IL 60208 , USA .
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14
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Hasenaka Y, Okamura TA, Tatsumi M, Inazumi N, Onitsuka K. Behavior of anionic molybdenum(IV, VI) and tungsten(IV, VI) complexes containing bulky hydrophobic dithiolate ligands and intramolecular NH···S hydrogen bonds in nonpolar solvents. Dalton Trans 2015; 43:15491-502. [PMID: 25190301 DOI: 10.1039/c4dt01646g] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molybdenum(IV, VI) and tungsten(IV, VI) complexes, (Et4N)2[M(IV)O{1,2-S2-3,6-(RCONH)2C6H2}2] and (Et4N)2[M(VI)O2{1,2-S2-3,6-(RCONH)2C6H2}2] (M = Mo, W; R = (4-(t)BuC6H4)3C), with bulky hydrophobic dithiolate ligands containing NH···S hydrogen bonds were synthesized. These complexes are soluble in nonpolar solvents like toluene, which allows the detection of unsymmetrical coordination structures and elusive intermolecular interactions in solution. The (1)H NMR spectra of the complexes in toluene-d8 revealed an unsymmetrical coordination structure, and proximity of the counterions to the anion moiety was suggested at low temperatures. The oxygen-atom-transfer reaction between the molybdenum(IV) complex and Me3NO in toluene was considerably accelerated in nonpolar solvents, and this increase was attributed to the favorable access of the substrate to the active center in the hydrophobic environment.
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Affiliation(s)
- Yuki Hasenaka
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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15
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Terranova U, de Leeuw NH. Aqueous Fe2S2 cluster: structure, magnetic coupling, and hydration behaviour from Hubbard U density functional theory. Phys Chem Chem Phys 2015; 16:13426-33. [PMID: 24881882 DOI: 10.1039/c4cp00984c] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
We present a DFT + U investigation of the all-ferrous Fe2S2 cluster in aqueous solution. We determine the value of U by tuning the geometry of the cluster in the gas-phase to that obtained by the highly accurate CCSD(T) method. When the optimised value of U is employed for the aqueous Fe2S2 cluster (Fe2S2(aq)), the resulting geometry agrees well with the X-ray diffraction structure, while the magnetic coupling is in line with the estimate from Mössbauer data. Molecular dynamics trajectories predict Fe2S2(aq) to be stable in water, regardless of the introduction of U. However, significant differences arise in the geometry, hydration, and exchange constant of the solvated clusters.
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Affiliation(s)
- Umberto Terranova
- Department of Chemistry, University College London, London, WC1H 0AJ, UK.
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Liu J, Chakraborty S, Hosseinzadeh P, Yu Y, Tian S, Petrik I, Bhagi A, Lu Y. Metalloproteins containing cytochrome, iron-sulfur, or copper redox centers. Chem Rev 2014; 114:4366-469. [PMID: 24758379 PMCID: PMC4002152 DOI: 10.1021/cr400479b] [Citation(s) in RCA: 559] [Impact Index Per Article: 55.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Indexed: 02/07/2023]
Affiliation(s)
- Jing Liu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Saumen Chakraborty
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Parisa Hosseinzadeh
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yang Yu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Shiliang Tian
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Igor Petrik
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Ambika Bhagi
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yi Lu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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Okamura TA, Kunisue K, Omi Y, Onitsuka K. Strong NH⋯S hydrogen bonds in molybdoenzyme models containing anilide moieties. Dalton Trans 2013; 42:7569-78. [DOI: 10.1039/c3dt50139f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Okamura TA, Ushijima Y, Omi Y, Onitsuka K. Systematic Investigation of Relationship between Strength of NH···S Hydrogen Bond and Reactivity of Molybdoenzyme Models. Inorg Chem 2012; 52:381-94. [DOI: 10.1021/ic302149p] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Taka-aki Okamura
- Department
of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yasuhito Ushijima
- Department
of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yui Omi
- Department
of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Kiyotaka Onitsuka
- Department
of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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Okamura TA, Tatsumi M, Omi Y, Yamamoto H, Onitsuka K. Selective and effective stabilization of Mo(VI)═O bonds by NH···S hydrogen bonds via trans influence. Inorg Chem 2012; 51:11688-97. [PMID: 23075211 DOI: 10.1021/ic301597d] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A monooxomolybdenum(IV) complex containing two intramolecular NH···S hydrogen bonds, (NEt(4))(2)[Mo(IV)O(1,2-S(2)-3-t-BuNHCOC(6)H(3))(2)], was synthesized. The trans isomer was crystallized as the major product, and the molecular structure was determined by X-ray analysis. The trans isomer was isomerized by heating in solution to give a 1:1 mixture of trans and cis isomers. Oxidation of these isomers by Me(3)NO afforded (NEt(4))(2)[Mo(VI)O(2)(1,2-S(2)-3-t-BuNHCOC(6)H(3))(2)]. (1)H NMR analysis revealed that the dioxomolybdenum(VI) complex existed as a single isomer where both oxo ligands were trans to each of the two hydrogen-bonded thiolate ligands. The Mo(VI)═O bond was effectively stabilized by the NH···S hydrogen bond via trans influence, which was determined using resonance Raman spectroscopy. These results were supported by preliminary density functional theory calculations.
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Affiliation(s)
- Taka-aki Okamura
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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Lang J, Santolini J, Couture M. The conserved Trp-Cys hydrogen bond dampens the "push effect" of the heme cysteinate proximal ligand during the first catalytic cycle of nitric oxide synthase. Biochemistry 2011; 50:10069-81. [PMID: 22023145 DOI: 10.1021/bi200965e] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Residues surrounding and interacting with the heme proximal ligand are important for efficient catalysis by heme proteins. The nitric oxide synthases (NOSs) are thiolate-coordinated enzymes that catalyze the hydroxylation of l-Arg in the first of the two catalytic cycles needed to synthesize nitric oxide. In NOSs, the indole NH group of a conserved tryptophan [W56 of the bacterial NOS-like protein from Staphylococcus aureus (saNOS)] forms a hydrogen bond with the heme proximal cysteinate ligand. The purpose of this study was to determine the impact of increasing (W56F and W56Y variants) or decreasing (W56H variant) the electron density of the proximal cysteinate ligand on molecular oxygen (O(2)) activation using saNOS as a model. We show that the removal of the indole NH···S(-) bond for W56F and W56Y caused an increase in the electron density of the cysteinate. This was probed by the decrease of the midpoint reduction potential (E(1/2)) along with weakened σ-bonding and strengthened π-backbonding with distal ligands (CO and O(2)). On the other hand, the W56H variant showed stronger Fe-OO and Fe-CO bonds (strengthened σ-bonding) along with an elevated E(1/2), which is consistent with the formation of a strong NH···S(-) hydrogen bond from H56. We also show here that changing the electron density of the proximal thiolate controls its "push effect"; whereas the rates of both O(2) activation and autoxidation of the Fe(II)O(2) complex increase with the stronger push effect created by removing the indole NH···S(-) hydrogen bond (W56F and W56Y variants), the W56H variant showed an increased stability of the complex against autoxidation and a slower rate of O(2) activation. These results are discussed with regard to the roles played by the conserved tryptophan-cysteinate interaction in the first catalytic cycle of NOS.
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Affiliation(s)
- Jérôme Lang
- Département de biochimie, de microbiologie et de bioinformatique, PROTEO and IBIS, pavillon Charles-Eugène Marchand, room 3163, Université Laval, Québec, Canada G1V 0A6
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21
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Biological Outer-Sphere Coordination. MOLECULAR ELECTRONIC STRUCTURES OF TRANSITION METAL COMPLEXES I 2011. [DOI: 10.1007/430_2011_49] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Maganas D, Grigoropoulos A, Staniland SS, Chatziefthimiou SD, Harrison A, Robertson N, Kyritsis P, Neese F. Tetrahedral and square planar Ni[(SPR(2))(2)N](2) complexes, R = Ph & (i)Pr revisited: experimental and theoretical analysis of interconversion pathways, structural preferences, and spin delocalization. Inorg Chem 2010; 49:5079-93. [PMID: 20462270 DOI: 10.1021/ic100163g] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sulfur-containing mono- or bidentate types of ligands, usually form square planar Ni((II))S(4) complexes. However, it has already been established that the bidentate L(-) dithioimidodiphosphinato ligands, [R(2)P(S)NP(S)R'(2)](-), R, and R' = aryl or alkyl, can afford both tetrahedral and square planar, NiS(4)-containing, homoleptic Ni(R,R')L(2) complexes, owing to an apparent structural flexibility, which has not, so far, been probed. In this work, the literature tetrahedral Ni[R(2)P(S)NP(S)R(2)](2) complexes, R = Ph (Ni(Ph,Ph)L(2), 1(Td)) and R = (i)Pr (Ni(iPr,iPr)L(2), 2) as well as the newly synthesized Ni[(i)Pr(2)P(S)NP(S)Ph(2)](2) complex (Ni(iPr,Ph)L(2), 3), have been studied by UV-vis, IR, and (31)P NMR spectroscopy. Complex 3 was shown by X-ray crystallography to be square planar, and magnetic studies confirmed that it is diamagnetic in the solid state. However, it becomes paramagnetic in solution, as it shows a similar UV-vis spectrum to one of the tetrahedral 1(Td) and 2 complexes. The crystal structure of the potassium salt of the asymmetric ligand, [(i)Pr(2)P(S)NP(S)Ph(2)]K, has also been determined and compared to those of the protonated (i)Pr(2)P(S)NHP(S)Ph(2) ligand and complex 3. All three, 1(Td), 2, and 3, Ni(R,R')L(2) complexes show strong paramagnetic effects in their solution (31)P NMR spectra. The magnetic properties of paramagnetic complexes 1 and 2 in the solid state were investigated on oriented crystals, and their analysis afforded remarkably small values of the spin-orbit coupling constant (lambda) and orbital reduction factor (k) parameters, implying significant delocalization of unpaired electronic density toward the ligands. The above experimental findings are combined with data from standard density functional theory and correlated multiconfiguration ab initio theoretical methods, in an effort to investigate the interplay between the square planar and tetrahedral geometries of the NiS(4) core, the mechanistic pathway for the spin-state interconversion, the degree of covalency of the Ni-S bonds, and the distribution of the spin density in this type of system. The analysis provides justification for the structural flexibility of such ligands, affording Ni(R,R')L(2) complexes with variable metallacycle conformation and NiS(4) core geometries. Of particular importance are the large zero-field splitting values estimated by both experimental and theoretical means, which have not, as yet, been verified by direct methods, such as electron paramagnetic resonance spectroscopy. The findings of our work confirm earlier observations on the feasibility of synthesizing either tetrahedral or square planar NiS(4) complexes containing the same type of ligands. They can also form the basis of investigating structure-properties relationships in other NiS(4)-containing systems.
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Affiliation(s)
- Dimitrios Maganas
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, GR-157 71 Athens, Greece
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Shimazaki Y, Takani M, Yamauchi O. Metal complexes of amino acids and amino acid side chain groups. Structures and properties. Dalton Trans 2009:7854-69. [PMID: 19771344 DOI: 10.1039/b905871k] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Namuswe F, Kasper GD, Sarjeant AAN, Hayashi T, Krest CM, Green MT, Moënne-Loccoz P, Goldberg DP. Rational tuning of the thiolate donor in model complexes of superoxide reductase: direct evidence for a trans influence in Fe(III)-OOR complexes. J Am Chem Soc 2008; 130:14189-200. [PMID: 18837497 DOI: 10.1021/ja8031828] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Iron peroxide species have been identified as important intermediates in a number of nonheme iron as well as heme-containing enzymes, yet there are only a few examples of such species either synthetic or biological that have been well characterized. We describe the synthesis and structural characterization of a new series of five-coordinate (N4S(thiolate))Fe(II) complexes that react with tert-butyl hydroperoxide ((t)BuOOH) or cumenyl hydroperoxide (CmOOH) to give metastable alkylperoxo-iron(III) species (N4S(thiolate)Fe(III)-OOR) at low temperature. These complexes were designed specifically to mimic the nonheme iron active site of superoxide reductase, which contains a five-coordinate iron(II) center bound by one Cys and four His residues in the active form of the protein. The structures of the Fe(II) complexes are analyzed by X-ray crystallography, and their electrochemical properties are assessed by cyclic voltammetry. For the Fe(III)-OOR species, low-temperature UV-vis spectra reveal intense peaks between 500-550 nm that are typical of peroxide to iron(III) ligand-to-metal charge-transfer (LMCT) transitions, and EPR spectroscopy shows that these alkylperoxo species are all low-spin iron(III) complexes. Identification of the vibrational modes of the Fe(III)-OOR unit comes from resonance Raman (RR) spectroscopy, which shows nu(Fe-O) modes between 600-635 cm(-1) and nu(O-O) bands near 800 cm(-1). These Fe-O stretching frequencies are significantly lower than those found in other low-spin Fe(III)-OOR complexes. Trends in the data conclusively show that this weakening of the Fe-O bond arises from a trans influence of the thiolate donor, and density functional theory (DFT) calculations support these findings. These results suggest a role for the cysteine ligand in SOR, and are discussed in light of the recent assessments of the function of the cysteine ligand in this enzyme.
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Affiliation(s)
- Frances Namuswe
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA
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Sengar RS, Miller JJ, Basu P. Design, syntheses, and characterization of dioxo-molybdenum(VI) complexes with thiolate ligands: effects of intraligand NH...S hydrogen bonding. Dalton Trans 2008:2569-77. [PMID: 18443699 PMCID: PMC4090030 DOI: 10.1039/b714386a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Presence of the hydrogen bonding near a metal center can influence the properties of the complex. Here, we describe changes in redox and spectral properties in discrete dioxo-molybdenum centers coordinated by a single thiolato ligand that can support an intra-ligand hydrogen bond. We have utilized thiophenolato ligands that can harbor hydrogen bonding between the thiophenolato sulfur with an amide functionality creating either a five- or a six-membered ring. Methylation of the amide functionality removes the NH...S hydrogen bonding thus providing a basis for understanding the effect of hydrogen bonding. These thiophenolato ligands have been used in synthesizing dioxo-MoVI complexes of type Tp*MoO2(S-o-RC6H4), where R=CONHMe (), CONMe2 (), NHCOMe (), and N(Me)COMe (). The complexes have been characterized by NMR, infrared, and UV-visible spectroscopy. Spectroscopic data clearly indicate the presence of hydrogen bonding in both and , and stronger in , where hydrogen bonding stabilizes a five-membered ring. All complexes exhibit a Mo(VI)/Mo(V) redox couple and redox potentials are modulated by the nature of H-bonding. Compound with the electron-releasing N(Me)COMe group has the highest reduction potential and is more difficult to reduce.
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Affiliation(s)
- Raghvendra S. Sengar
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282
| | - Jonathan J. Miller
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282
| | - Partha Basu
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282
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Baba K, Okamura TA, Yamamoto H, Yamamoto T, Ueyama N. Zinc, cadmium, and mercury 1,2-benzenedithiolates with intramolecular NH...S hydrogen bonds. Inorg Chem 2008; 47:2837-48. [PMID: 18330987 DOI: 10.1021/ic702037k] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mononuclear Zn, Cd, and Hg 1,2-benzenedithiolates with intramolecular NH...S hydrogen bonds, [M(II){1,2-S2-3,6-(RCONH)2C6H2}2](2-) (R = CH 3, t-Bu; M = Zn, Cd, Hg), were synthesized and characterized by X-ray analysis and spectral measurements. The presence of intramolecular NH...S hydrogen bonds was established by the IR spectra. (199)Hg and (113)Cd nuclear magnetic resonance showed a stabilized four-thiolate coordinated structure and suggested the influence of the NH...S hydrogen bonds to ppi(Hg)-ppi(S) interactions. The NH stretching bands show that the NH...S hydrogen bonds in Cd and Hg complexes are stronger than those in the corresponding Zn complex. These results are supported by theoretical calculations. The experimental and theoretical results suggested that the NH...S hydrogen bond influences the efficient capture of toxic Cd and Hg ions by metallothioneins.
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Affiliation(s)
- Koji Baba
- Chemical Analysis Research Center, National Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki 305-8604, Japan
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Yu Z, Wang M, Li P, Dong W, Wang F, Sun L. Diiron dithiolate complexes containing intra-ligand NH⋯S hydrogen bonds: [FeFe] hydrogenase active site models for the electrochemical proton reduction of HOAc with low overpotential. Dalton Trans 2008:2400-6. [DOI: 10.1039/b715990k] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Okamura TA, Iwamura T, Yamamoto H, Ueyama N. Synthesis and molecular structures of S-2-FcNHCOC6H4SH and [MIII(OEP)(S-2-FcNHCOC6H4)] (Fc=ferrocenyl, M=Fe, Ga): Electrochemical contributions of intramolecular SH⋯OC and NH⋯S hydrogen bonds. J Organomet Chem 2007. [DOI: 10.1016/j.jorganchem.2006.08.067] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kawamoto T, Suzuki S, Konno T. Synthesis and characterization of cyclometallated palladium(II) and platinum(II) complexes with amide-thiolate ligands. J Organomet Chem 2007. [DOI: 10.1016/j.jorganchem.2006.08.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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31
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Bresson C, Spezia R, Esnouf S, Solari PL, Coantic S, Den Auwer C. A combined spectroscopic and theoretical approach to investigate structural properties of Co(ii)/Co(iii) tris-cysteinato complexes in aqueous medium. NEW J CHEM 2007. [DOI: 10.1039/b707055a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Madhu V, Das SK. N–H···S Hydrogen Bonds in a New Family of Ion-Pair Complexes Between Cationic Nickel Tetraazabicyclononane and Anionic Metal Dithiolates: Synthesis, Characterization and Properties of [Ni(C9H22N6)][M(mnt)2](MII = Cu, Ni, Pd). Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200500751] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Glaser T, Liratzis I, Kataeva O, Fröhlich R, Piacenza M, Grimme S. Direct influence of hydrogen-bonding on the reduction potential of a CuII center. Chem Commun (Camb) 2006:1024-6. [PMID: 16491197 DOI: 10.1039/b517340j] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two hydrogen-bonds from geometrically constrained OH groups to coordinated oxygen donors shift the reduction potential of a Cu(II) complex by +270 mV as compared to the structurally analogous reference complex missing the OH groups.
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Affiliation(s)
- Thorsten Glaser
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany.
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Abstract
Metal-thiolate active sites play major roles in bioinorganic chemistry. The M--S(thiolate) bonds can be very covalent, and involve different orbital interactions. Spectroscopic features of these active sites (intense, low-energy charge transfer transitions) reflect the high covalency of the M--S(thiolate) bonds. The energy of the metal-thiolate bond is fairly insensitive to its ionic/covalent and pi/sigma nature as increasing M--S covalency reduces the charge distribution, hence the ionic term, and these contributions can compensate. Thus, trends observed in stability constants (i.e., the Irving-Williams series) mostly reflect the dominantly ionic contribution to bonding of the innocent ligand being replaced by the thiolate. Due to high effective nuclear charges of the Cu(II) and Fe(III) ions, the cupric- and ferric-thiolate bonds are very covalent, with the former having strong pi and the latter having more sigma character. For the blue copper site, the high pi covalency couples the metal ion into the protein for rapid directional long range electron transfer. For rubredoxins, because the redox active molecular orbital is pi in nature, electron transfer tends to be more localized in the vicinity of the active site. Although the energy of hydrogen bonding of the protein environment to the thiolate ligands tends to be fairly small, H-bonding can significantly affect the covalency of the metal-thiolate bond and contribute to redox tuning by the protein environment.
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Affiliation(s)
- Edward I Solomon
- Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305, USA.
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Dey A, Okamura TA, Ueyama N, Hedman B, Hodgson KO, Solomon EI. Sulfur K-edge XAS and DFT calculations on P450 model complexes: effects of hydrogen bonding on electronic structure and redox potentials. J Am Chem Soc 2005; 127:12046-53. [PMID: 16117545 PMCID: PMC2880190 DOI: 10.1021/ja0519031] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrogen bonding (H-bonding) is generally thought to play an important role in tuning the electronic structure and reactivity of metal-sulfur sites in proteins. To develop a quantitative understanding of this effect, S K-edge X-ray absorption spectroscopy (XAS) has been employed to directly probe ligand-metal bond covalency, where it has been found that protein active sites are significantly less covalent than their related model complexes. Sulfur K-edge XAS data are reported here on a series of P450 model complexes with increasing H-bonding to the ligated thiolate from its substituent. The XAS spectroscopic results show a dramatic decrease in preedge intensity. DFT calculations reproduce these effects and show that the observed changes are in fact solely due to H-bonding and not from the inductive effect of the substituent on the thiolate. These calculations also indicate that the H-bonding interaction in these systems is mainly dipolar in nature. The -2.5 kcal/mol energy of the H-bonding interaction was small relative to the large change in ligand-metal bond covalency (30%) observed in the data. A bond decomposition analysis of the total energy is developed to correlate the preedge intensity change to the change in Fe-S bonding interaction on H-bonding. This effect is greater for the reduced than the oxidized state, leading to a 260 mV increase in the redox potential. A simple model shows that E degrees should vary approximately linearly with the covalency of the Fe-S bond in the oxidized state, which can be determined directly from S K-edge XAS.
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Affiliation(s)
- Abhishek Dey
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Taka-aki Okamura
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Norikazu Ueyama
- Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Britt Hedman
- Stanford Synchrotron Radiation Laboratory, Stanford University, SLAC, Menlo Park, 94025
| | - Keith O. Hodgson
- Department of Chemistry, Stanford University, Stanford, CA 94305
- Stanford Synchrotron Radiation Laboratory, Stanford University, SLAC, Menlo Park, 94025
| | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, CA 94305
- Corresponding author:
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Okamura TA, Sakauye K, Doi M, Yamamoto H, Ueyama N, Nakamura A. Observation of a Large Current on the Cyclic Voltammetry of Acylaminoferrocenes in the Solid State: An Efficient Electron-Transfer Pathway through Continuous NH···O=C Hydrogen-Bond Chains and π-Conjugation. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2005. [DOI: 10.1246/bcsj.78.1270] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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37
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Kojima T, Matsuda Y. A Novel Ru(II)–DMSO Complex Having Non-coordinating 1-Naphthoylamide Arm: Effects of Intramolecular Hydrogen Bonding on Redox Potential of the Ruthenium Center. CHEM LETT 2005. [DOI: 10.1246/cl.2005.258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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38
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Takahashi K, Kobayashi A, Doi M, Adachi S, Taguchi T, Okamura TA, Yamamoto H, Ueyama N. Restriction of CaCO3 polymorph by NH⋯O hydrogen-bonded poly(methacryloylaminocarboxylate) ligands: induced polymorph change by strength and/or formation manner of hydrogen bond. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b415692g] [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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39
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Baba K, Okamura TA, Yamamoto H, Yamamoto T, Ohama M, Ueyama N. Monooxomolybdenum(IV) Complex with Extremely Bulky Dithiolate Ligands — Acceleration of O-atom Transfer by Distorted Square Pyramidal Conformation. CHEM LETT 2005. [DOI: 10.1246/cl.2005.44] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Sundaresan C, Dixit S, Venugopalan P. A supramolecular assembly dominated by N–H⋯S hydrogen bonds: Structure of 2-thioureidobenzoxazole by single crystal X-ray diffraction. J Mol Struct 2004. [DOI: 10.1016/j.molstruc.2004.01.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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41
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Venkateswara Rao P, Holm RH. Synthetic Analogues of the Active Sites of Iron−Sulfur Proteins. Chem Rev 2004; 104:527-59. [PMID: 14871134 DOI: 10.1021/cr020615+] [Citation(s) in RCA: 412] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P Venkateswara Rao
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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Chiou SJ, Riordan CG, Rheingold AL. Synthetic modeling of zinc thiolates: quantitative assessment of hydrogen bonding in modulating sulfur alkylation rates. Proc Natl Acad Sci U S A 2003; 100:3695-700. [PMID: 12649324 PMCID: PMC152984 DOI: 10.1073/pnas.0637221100] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A series of mononuclear zinc thiolate complexes have been prepared and fully characterized. The reactions of the complexes with alkyl halides, leading to zinc halides and the corresponding thioethers, have been examined by kinetic methods. In toluene, the reactions obey a second-order rate law displaying activation parameters consistent with a S(N)2 attack of the zinc-bound thiolate on the carbon electrophile. Intramolecular hydrogen bonding of an amide NH to the thiolate sulfur reduces the nucleophilicity and consequently, the rate of alkylation more than 30-fold at 25 degrees C. The H-bonding shows an inverse HD isotope effect of 0.33 (60 degrees C) ascribed to differential H-bonding for the two isotopomers due to zero point energy differences. These model studies provide quantitative evaluation of H-bonding on reaction rates relevant to zinc thiol-activating proteins.
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Affiliation(s)
- Show-Jen Chiou
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
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Smith JN, Shirin Z, Carrano CJ. Control of thiolate nucleophilicity and specificity in zinc metalloproteins by hydrogen bonding: lessons from model compound studies. J Am Chem Soc 2003; 125:868-9. [PMID: 12537475 DOI: 10.1021/ja029418i] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A single hydrogen bond between an amide N-H and a thiolate sulfur in model complexes designed to mimic the binding site of zinc thiolate proteins, is shown to reduce the reactivity of the thiolate toward electrophiles by up to 2 orders of magnitude. In addition a single such bond is also sufficient to achieve nearly 100% regiospecificity of reaction between a strong, and hence inherently indiscriminate, alkylating agent like trimethyl oxonium tetrafluoroborate and a single sulfur in a dithiolate construct. The importance of these results in understanding how two systems such as the zinc fingers of the GATA family and the Escherichia coli DNA repair protein Ada which share the same pseudotetrahedral structure and tetrascysteinyl ligation around the zinc can fulfill such widely divergent (structural vs reactive) roles and how specificity of reaction in multithiolate-containing systems can be achieved is discussed.
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Affiliation(s)
- Jennifer N Smith
- Department of Chemistry and Biochemistry, Southwest Texas State University, San Marcos, TX 78666, USA
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45
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Preparation and properties of dinuclear bis[dicarbonyl(cyclopentadienyl)]diiron(II) complexes with SS coupled, dimerized sulfur-rich dithiolate ligands. J Organomet Chem 2002. [DOI: 10.1016/s0022-328x(01)01320-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Liaw WF, Hsieh CK, Lin GY, Lee GH. Syntheses, reactivity, and pi-donating ligand metathesis reaction of five-coordinate sixteen-electron manganese(I) complexes: crystal structures of [Mn(CO(3)(-TeC(6)H(4)-o-NH-)](-), [(Mn(CO)(3))2(mu-SC(6)H(4)-o-S--S--C(6)H(4)-o-mu-S--)], [(CO)(3)Mn(mu-SC(6)H(4)-o-NH(2)-)]2, and [(CO)(3)Mn(mu-SC(8)N(2)H(4)-o-S-)](2)(2-). Inorg Chem 2001; 40:3468-75. [PMID: 11421694 DOI: 10.1021/ic000795a] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The preparation of the varieties of five-coordinate sixteen-electron manganese(I) complexes [Mn(CO)(3)(-EC(6)H(4)-o-E'-)](-) (E = Te, Se, S, O; E' = NH, S, O) by (a) oxidative addition of 2-aminophenyl dichalcogenides to anionic manganese(0)-carbonyl, (b) pi-donating ligand metathesis reaction of complex [Mn(CO)(3)(-TeC(6)H(4)-o-NH-)](-), and (c) reduction /deprotonation of the neutral dimetallic [(Mn(CO)(3))(2)(mu-SC(6)H(4)-o-S-S-C(6)H(4)-o-mu-S-)]/[(CO)(3)Mn(mu-SC(6)H(4)-o-NH(2)-)](2) proved successful approaches in this direction. The IR nu(CO) data of the coordinatively and electronically unsaturated [Mn(CO)(3)(-EC(6)H(4)-o-E'-)](-) (E = Te, Se, S, O; E' = NH, S, O) complexes suggest the relative order of pi-donating ability of the series of bidentate ligands being [TeC(6)H(4)-o-NH](2)(-) > [SeC(6)H(4)-o-NH](2)(-) > [SC(6)H(4)-o-NH](2)(-) > [SC(6)H(4)-o-S](2)(-) > [SC(6)H(4)-o-O](2)(-) > [OC(6)H(4)-o-O](2)(-). Proton NMR spectra of the [Mn(CO)(3)(-EC(6)H(4)-o-NH-)](-) (E = Te, Se, S) derivatives show the low-field shift of the amide proton ((1)H NMR (C(4)D(8)O): delta 9.66 (br) ppm (E = Te), 9.32 (br) ppm (E = Se), 8.98 (br) ppm (E = S)). The formation of the dimetallic [(CO)(3)Mn(mu-SC(8)N(2)H(4)-o-S-)](2)(2-) can be interpreted as coordinative association of two units of unstable mononuclear [(CO)(3)Mn(-SC(8)N(2)H(4)-o-S-)](-) and reflects the pi-donating ability of the bidentate ligand is responsible for the formation of pentacoordinate, sixteen-electron manganese(I) carbonyl complexes. The neutral bimetallic manganese(I)-bismercaptophenyl disulfide complex [(Mn(CO)(3))(2)(mu-SC(6)H(4)-o-S-S-C(6)H(4)-o-mu-S-)] with internal S-S bond length of 2.222(1) A and the five-coordinate sixteen-electron complex [Mn(CO)(3)(-SC(6)H(4)-o-S-)](-) are chemically interconvertible. In a similar fashion, treatment of complex [Mn(CO)(3)(-SC(6)H(4)-o-NH-)](-) with HBF(4) yielded neutral dinuclear complex [(CO)(3)Mn(mu-SC(6)H(4)-o-NH(2)-)](2) and showed that the amine deprotonation is reversible. Investigations of pi-donating ligand metathesis reactions of complex [Mn(CO)(3)(-TeC(6)H(4)-o-NH-)](-) revealed that the stable intermediate, not the pi-donating ability of bidentate ligands, is responsible for the final protonation/oxidation product. This argument is demonstrated by reaction of [Mn(CO)(3)(-TeC(6)H(4)-o-NH-)](-) with 1,2-benzenedithiol, hydroxythiophenol, and catechol, respectively leading to the formation of [Mn(CO)(3)(-EC(6)H(4)-o-E'-)](-) (E = S, O; E' = S, O), although any pi-donor containing the amido group is a more effective donor than any other pi-donor lacking an amido group. Also, the reactions of [Mn(CO)(3)(-TeC(6)H(4)-o-NH-)](-) with electrophiles occurring at the more electron-rich amide site support that the more electron-rich amide donor of the chelating 2-tellurolatophenylamido occupies an equatorial site as indicated by a shorter Mn(I)-N bond length of the distorted trigonal bipyramidal [Mn(CO)(3)(-TeC(6)H(4)-o-NH-)](-).
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Affiliation(s)
- W F Liaw
- Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan
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François S, Rohmer MM, Bénard M, Moreland AC, Rauchfuss TB. The N−H···S Hydrogen Bond in (TACN)2Fe2S6 (TACN = Triazacyclononane) and in Model Systems Involving the Persulfido Moiety: An ab Initio and DFT Study. J Am Chem Soc 2000. [DOI: 10.1021/ja0011717] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stéphane François
- Contribution from the Laboratoire de Chimie Quantique, UMR 7551, CNRS and Université Louis Pasteur, F-67000 Strasbourg, France, and School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801
| | - Marie-Madeleine Rohmer
- Contribution from the Laboratoire de Chimie Quantique, UMR 7551, CNRS and Université Louis Pasteur, F-67000 Strasbourg, France, and School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801
| | - Marc Bénard
- Contribution from the Laboratoire de Chimie Quantique, UMR 7551, CNRS and Université Louis Pasteur, F-67000 Strasbourg, France, and School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801
| | - Andrew C. Moreland
- Contribution from the Laboratoire de Chimie Quantique, UMR 7551, CNRS and Université Louis Pasteur, F-67000 Strasbourg, France, and School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801
| | - Thomas B. Rauchfuss
- Contribution from the Laboratoire de Chimie Quantique, UMR 7551, CNRS and Université Louis Pasteur, F-67000 Strasbourg, France, and School of Chemical Sciences, University of Illinois, Urbana, Illinois 61801
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Liaw WF, Lee NH, Chen CH, Lee CM, Lee GH, Peng SM. Dinuclear and Mononuclear Iron(II)−Thiolate Complexes with Mixed CO/CN- Ligands: Synthetic Advances for Iron Sites of [Fe]-Only Hydrogenases. J Am Chem Soc 2000. [DOI: 10.1021/ja992300q] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wen-Feng Liaw
- Contribution form the Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan, and Instrumentation Center and Department of Chemistry, National Taiwan University, Taipei 10764, Taiwan
| | - Nan-Hung Lee
- Contribution form the Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan, and Instrumentation Center and Department of Chemistry, National Taiwan University, Taipei 10764, Taiwan
| | - Chien-Hong Chen
- Contribution form the Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan, and Instrumentation Center and Department of Chemistry, National Taiwan University, Taipei 10764, Taiwan
| | - Chien-Ming Lee
- Contribution form the Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan, and Instrumentation Center and Department of Chemistry, National Taiwan University, Taipei 10764, Taiwan
| | - Gene-Hsiang Lee
- Contribution form the Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan, and Instrumentation Center and Department of Chemistry, National Taiwan University, Taipei 10764, Taiwan
| | - Shie-Ming Peng
- Contribution form the Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan, and Instrumentation Center and Department of Chemistry, National Taiwan University, Taipei 10764, Taiwan
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Anjali K, Sampanthar JT, Vittal JJ. Chemistry of functionalized thiolates: syntheses and structures of neutral, monomeric [Zn(SC6H4X-4)2(NN)], where X=H, NH2 and OH, and (NN)=nitrogen bases 2,2′-bpy, phen and tmen. Inorganica Chim Acta 1999. [DOI: 10.1016/s0020-1693(99)00267-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Characterization of ferrocene derivatives bearing podand dipeptide chains (-l-Ala-l-Pro-OR). J Organomet Chem 1999. [DOI: 10.1016/s0022-328x(99)00301-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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