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Vinod Mouli MSS, Kumar Mishra A. Divergent Crystallographic Architecture for Silver‐Flavin Complexes Induced via pH Variation. ChemistrySelect 2022. [DOI: 10.1002/slct.202202126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- M. S. S. Vinod Mouli
- Department of Chemistry Indian Institute of Technology Hyderabad Kandi Sangareddy 502285 Telangana
| | - Ashutosh Kumar Mishra
- Department of Chemistry Indian Institute of Technology Hyderabad Kandi Sangareddy 502285 Telangana
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Mouli MSSV, Mishra AK. Formation of the silver-flavin coordination polymers and their morphological studies. CrystEngComm 2022. [DOI: 10.1039/d2ce00071g] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This Communication describes the formation of 1D-coordination polymeric motifs involving modified flavin analog connected together through intervening silver ions. Rare bidentate coordination mode for model flavin was achieved with silver...
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Mouli MSSV, Mishra AK. Modulating catalytic activity of a modified flavin analogue via judicially positioned metal ion toward aerobic sulphoxidation. RSC Adv 2022; 12:3990-3995. [PMID: 35425444 PMCID: PMC8981109 DOI: 10.1039/d1ra06558k] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/15/2021] [Indexed: 01/24/2023] Open
Abstract
This manuscript describes the synthesis, spectroscopic and crystallographic characterization of a cadmium complex of 10-propoylisoalloxazine-7-carboxylic acid (Flc-Cd). Catalytic activity of Flc-Cd towards aerobic sulphoxidation reaction was investigated in the presence of l-ascorbic acid as the reducing agent. Notably the neutral un-metalated flavin analogue did not show any significant catalytic activity. The design strategy for Flc provides a close proximity of the metal centre to the flavin core without compromising the catalytic site thereby assisting the product formation when compared to unmetallated Flc. Minor enantioselectivity is also observed in cases where unsymmetrical sulphides were used; indicative of the possible involvement of chiral l-ascorbic acid in the intermediate formation. Design and synthesis of a catalytically efficient metal-flavin complex toward aerobic sulphoxidation was achieved via judicially positioning the metal ion near the catalytic site thereby assisting the intermediate formation.![]()
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Affiliation(s)
- M. S. S. Vinod Mouli
- Department of Chemistry, Indian Institute of Technology-Hyderabad, Kandi-502284, India
| | - Ashutosh Kumar Mishra
- Department of Chemistry, Indian Institute of Technology-Hyderabad, Kandi-502284, India
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Guo H, Zhu L, Dang C, Zhao J, Dick B. Synthesis and photophysical properties of ruthenium(ii) polyimine complexes decorated with flavin. Phys Chem Chem Phys 2018; 20:17504-17516. [DOI: 10.1039/c8cp02358a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Phosphorescent emission from a flavin localized triplet excited state (3IL) is observed for the first time in a flavin decorated tris(dipyridine) Ru(ii) complex with strong visible light absorption.
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Affiliation(s)
- Huimin Guo
- State Key Laboratory of Fine Chemicals
- School of Chemistry
- Dalian University of Technology
- Dalian
- P. R. China
| | - Lijuan Zhu
- State Key Laboratory of Fine Chemicals
- School of Chemistry
- Dalian University of Technology
- Dalian
- P. R. China
| | - Can Dang
- State Key Laboratory of Fine Chemicals
- School of Chemistry
- Dalian University of Technology
- Dalian
- P. R. China
| | - Jianzhang Zhao
- State Key Laboratory of Fine Chemicals
- School of Chemistry
- Dalian University of Technology
- Dalian
- P. R. China
| | - Bernhard Dick
- Institut für Physikalische und Theoretische Chemie
- Universität Regensburg
- Regensburg
- Germany
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Mondal P, Ray R, Das A, Lahiri GK. Revelation of Varying Bonding Motif of Alloxazine, a Flavin Analogue, in Selected Ruthenium(II/III) Frameworks. Inorg Chem 2015; 54:3012-21. [DOI: 10.1021/acs.inorgchem.5b00122] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Prasenjit Mondal
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India 400076
| | - Ritwika Ray
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India 400076
| | - Ankita Das
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India 400076
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India 400076
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D'Souza F, Imahori H. Preface — Special Issue in Honor of Professor Shunichi Fukuzumi. J PORPHYR PHTHALOCYA 2015. [DOI: 10.1142/s1088424615020010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Weisser F, Hohloch S, Plebst S, Schweinfurth D, Sarkar B. Ruthenium complexes of tripodal ligands with pyridine and triazole arms: subtle tuning of thermal, electrochemical, and photochemical reactivity. Chemistry 2014; 20:781-93. [PMID: 24403171 DOI: 10.1002/chem.201303640] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 10/30/2013] [Indexed: 01/02/2023]
Abstract
Electrochemical and photochemical bond-activation steps are important for a variety of chemical transformations. We present here four new complexes, [Ru(L(n) )(dmso)(Cl)]PF6 (1-4), where L(n) is a tripodal amine ligand with 4-n pyridylmethyl arms and n-1 triazolylmethyl arms. Structural comparisons show that the triazoles bind closer to the Ru center than the pyridines. For L(2) , two isomers (with respect to the position of the triazole arm, equatorial or axial), trans-2sym and trans-2un , could be separated and compared. The increase in the number of the triazole arms in the ligand has almost no effect on the Ru(II) /Ru(III) oxidation potentials, but it increases the stability of the RuSdmso bond. Hence, the oxidation waves become more reversible from trans-1 to trans-4, and whereas the dmso ligand readily dissociates from trans-1 upon heating or irradiation with UV light, the RuS bond of trans-4 remains perfectly stable under the same conditions. The strength of the RuS bond is not only influenced by the number of triazole arms but also by their position, as evidenced by the difference in redox behavior and reactivity of the two isomers, trans-2sym and trans-2un . A mechanistic picture for the electrochemical, thermal, and photochemical bond activation is discussed with data from NMR spectroscopy, cyclic voltammetry, and spectroelectrochemistry.
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Affiliation(s)
- Fritz Weisser
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, 14195 Berlin (Germany), Fax: (+49) 30-838-53310
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Abstract
(1)H-, (11)B-, (13)C-, (15)N-, (17)O-, (19)F-, and (31)P-NMR chemical shifts of flavocoenzymes and derivatives of it, as well as of alloxazines and isoalloxazinium salts, from NMR experiments performed under various experimental conditions (e.g., dependence of the chemical shifts on temperature, concentration, solvent polarity, and pH) are reported. Also solid-state (13)C- and (15)N-NMR experiments are described revealing the anisotropic values of corresponding chemical shifts. These data, in combination with a number of coupling constants, led to a detailed description of the electronic structure of oxidized and reduced flavins. The data also demonstrate that the structure of oxidized flavin can assume a configuration deviating from coplanarity, depending on substitutions in the isoalloxazine ring, while that of reduced flavin exhibits several configurations, from almost planar to quite bended. The complexes formed between oxidized flavin and metal ions or organic molecules revealed three coordination sites with metal ions (depending on the chemical nature of the ion), and specific interactions between the pyrimidine moiety of flavin and organic molecules, mimicking specific interactions between apoflavoproteins and their coenzymes. Most NMR studies on flavoproteins were performed using (13)C- and (15)N-substituted coenzymes, either specifically enriched in the pterin moiety of flavin or uniformly labeled flavins. The chemical shifts of free flavins are used as a guide in the interpretation of the chemical shifts observed in flavoproteins. Although the hydrogen-bonding pattern in oxidized and reduced flavoproteins varies considerably, no correlation is obvious between these patterns and the corresponding redox potentials. In all reduced flavoproteins the N(1)H group of the flavocoenzyme is deprotonated, an exception is thioredoxin reductase. Three-dimensional structures of only a few flavoproteins, mostly belonging to the family of flavodoxins, have been solved. Also the kinetics of unfolding and refolding of flavodoxins has been investigated by NMR techniques. In addition, (31)P-NMR data of all so far studied flavoproteins and some (19)F-NMR spectra are discussed.
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Affiliation(s)
- Franz Müller
- , Wylstrasse 13, CH-6052, Hergiswil, Switzerland,
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Al-Jibori SA, Ahmed SA, Wagner C, Schmidt H, Hogarth G. Synthesis and molecular structure of the twelve-membered metallamacrocycle [Hg2(μ-2,6-dapy)2] (2,6-dapyH2=2,6-diacetamidopyridine). Inorganica Chim Acta 2014. [DOI: 10.1016/j.ica.2013.10.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Schweinfurth D, Khusniyarov MM, Bubrin D, Hohloch S, Su CY, Sarkar B. Tuning spin-spin coupling in quinonoid-bridged dicopper(II) complexes through rational bridge variation. Inorg Chem 2013; 52:10332-9. [PMID: 24010410 DOI: 10.1021/ic400955c] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bridged metal complexes [{Cu(tmpa)}2(μ-L(1)-2H)](ClO4)2 (1), [{Cu(tmpa)}2(μ-L(2)-2H)](ClO4)2 (2), [{Cu(tmpa)}2(μ-L(3)-2H)](BPh4)2 (3), and [{Cu(tmpa)}2(μ-L(4)-2H)](ClO4)2 (4) (tmpa = tris(2-pyridylmethyl)amine, L(1) = chloranilic acid, L(2) = 2,5-dihydroxy-1,4-benzoquinone, L(3) = (2,5-di-[2-(methoxy)-anilino]-1,4-benzoquinone, L(4) = azophenine) were synthesized from copper(II) salts, tmpa, and the bridging quinonoid ligands in the presence of a base. X-ray structural characterization of the complexes showed a distorted octahedral environment around the copper(II) centers for the complexes 1-3, the donors being the nitrogen atoms of tmpa, and the nitrogen or oxygen donors of the bridging quinones. In contrast, the copper(II) centers in 4 display a distorted square-pyramidal coordination, where one of the pyridine arms of each tmpa remains uncoordinated. Bond-length analyses within the bridging ligand exhibit localization of the double bonds inside the bridge for 1-3. In contrast, complete delocalization of double bonds within the bridging ligand is observed for 4. Temperature-dependent magnetic susceptibility measurements on the complexes reveal an antiferromagnetic coupling between the copper(II) ions. The strength of antiferromagnetic coupling was observed to depend on the energy of the HOMO of the bridging quinone ligands, with exchange coupling constants J in the range between -23.2 and -0.6 cm(-1) and the strength of antiferromagnetic coupling of 4 > 3 > 2 > 1. Broken-symmetry density functional theory calculations (DFT) revealed that the orientation of magnetic orbitals in 1 and 2 is different than that in 3 and 4, and this results in two different exchange pathways. These results demonstrate how bridge-mediated spin-spin coupling in quinone-bridged metal complexes can be strongly tuned by a rational design of the bridging ligand employing the [O] for [NR] isoelectronic analogy.
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Affiliation(s)
- David Schweinfurth
- Institut für Chemie und Biochemie, Freie Universität Berlin , Fabeckstrasse 34-36, D-14195, Berlin, Germany
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Sawaki T, Ishizuka T, Kawano M, Shiota Y, Yoshizawa K, Kojima T. Complete photochromic structural changes in ruthenium(II)-diimine complexes, based on control of the excited states by metalation. Chemistry 2013; 19:8978-90. [PMID: 23681489 DOI: 10.1002/chem.201300437] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/28/2013] [Indexed: 11/08/2022]
Abstract
The thermal and photochemical reactions of a newly synthesized complex, [Ru(II)(TPA)(tpphz)](2+) (1; TPA=tris(2-pyridylmethyl)amine, tpphz=tetrapyrido[3,2-a:2',3'-c:3'',2''-h: 2''',3'''-j]phenazine), and its derivatives have been investigated. Heating a solution of complex 1 (closed form) and its derivatives in MeCN caused the partial dissociation of one pyridylmethyl moiety of the TPA ligand and the resulting vacant site on the Ru(II) center was occupied by a molecule of MeCN from the solvent to give a dissociated complex, [Ru(II)(η(3)-TPA)(tpphz)(MeCN)](2+) (1', open form), and its derivatives, respectively, in quantitative yields. The thermal dissociation reactions were investigated on the basis of kinetics analysis, which indicated that the reactions proceeded through a seven-coordinate transition state. Although the backwards reaction was induced by photoirradiation of the MLCT absorption bands, the photoreaction of complex 1' reached a photostationary state between complexes 1 and 1' and, hence, the recovery of complex 1 from complex 1' was 67%. Upon protonation of complex 1 at the vacant site of the tpphz ligand, the efficiency of the photoinduced recovery of complex 1+H(+) from complex 1'+H(+) improved to 83%. In contrast, dinuclear μ-tpphz complexes 2 and 3, which contained the Ru(II)(TPA)(tpphz) unit and either a Ru(II)(bpy)2 or Pd(II)Cl2 moiety on the other coordination edge of the tpphz ligand, exhibited 100% photoconversion from their open forms into their closed forms (2'→2 and 3'→3). These results are the first examples of the complete photochromic structural change of a transition-metal complex, as represented by complete interconversion between its open and closed forms. Scrutinization by performing optical and electrochemical measurements allowed us to propose a rationale for how metal coordination at the vacant site of the tpphz ligand improves the efficiency of photoconversion from the open form into the closed form. It is essential to lower the energy level of the triplet metal-to-ligand charge-transfer excited state ((3)MLCT*) of the closed form relative to that of the triplet metal-centered excited state ((3)MC*) by metal coordination. This energy-level manipulation hinders the transition from the (3)MLCT* state into the (3)MC* state in the closed form to block the partial photodissociation of the TPA ligand.
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Affiliation(s)
- Takuya Sawaki
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571, Japan
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Inui Y, Shiro M, Kusukawa T, Fukuzumi S, Kojima T. A triangular prismatic hexanuclear iridium(III) complex bridged by flavin analogues showing reversible redox processes. Dalton Trans 2013; 42:2773-8. [PMID: 23235491 DOI: 10.1039/c2dt32535g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
[Ir(6)(μ-alloCl(2)(2-))(3)(Cp*)(6)(OH)(3)](PF(6))(3) (1) having 7,8-dichloroalloxazine dianion (alloCl(2)(2-)) as bridging ligands was synthesized and characterized by X-ray crystallography, spectroscopic and electrochemical measurements. The alloxazine ligands showed unprecedented coordination modes to link the six Ir(III) centres. The complex exhibited remarkable stability and reversible six-electron redox processes at the bridging alloxazine ligands in organic solvents. The first reversible reduction process occurred on each of three alloxazine ligands in 1 to produce a three-electron-reduced species, [Ir(III)(6)Cp*(6)(μ-alloCl(2)˙(3-))(3)(OH)(3)], and was observed as an apparent one-step reduction process at -0.65 V (vs. Fc(0/+)). The second reversible reduction process on each of the three alloxazine ligands in 1 was recorded at almost the same potential, -0.78 V (vs. Fc(0/+)), to afford the six-electron-reduced form, [Ir(III)(6)Cp*(6)(μ-alloCl(2)(4-))(3)(OH)(3)](3-). The radical anion of the alloxazine derivative was detected by EPR measurements at room temperature. After the six-electron reduction of 1 with cobaltocene, the backward oxidation processes of reduced forms with p-chloranil were traced by UV-Vis spectroscopy to confirm the recovery of the original spectrum of 1.
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Affiliation(s)
- Yuji Inui
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, and ALCA (JST), 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan
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Inui Y, Miyazaki S, Ohkubo K, Fukuzumi S, Kojima T. Regulation of Redox Potential of a Pterin Derivative Bound to a Ruthenium(II) Complex by Intermolecular Hydrogen Bonding with Nucleobases. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201108827] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Inui Y, Miyazaki S, Ohkubo K, Fukuzumi S, Kojima T. Regulation of Redox Potential of a Pterin Derivative Bound to a Ruthenium(II) Complex by Intermolecular Hydrogen Bonding with Nucleobases. Angew Chem Int Ed Engl 2012; 51:4623-7. [DOI: 10.1002/anie.201108827] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Indexed: 11/10/2022]
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Ishizuka T, Sawaki T, Miyazaki S, Kawano M, Shiota Y, Yoshizawa K, Fukuzumi S, Kojima T. Mechanistic Insights into Photochromic Behavior of a Ruthenium(II)-Pterin Complex. Chemistry 2011; 17:6652-62. [DOI: 10.1002/chem.201003522] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Indexed: 11/06/2022]
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Weisser F, Huebner R, Schweinfurth D, Sarkar B. Energy-Level Tailoring in a Series of Redox-Rich Quinonoid-Bridged Diruthenium Complexes Containing Tris(2-pyridylmethyl)amine as a Co-Ligand. Chemistry 2011; 17:5727-36. [DOI: 10.1002/chem.201003253] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Takai A, Chkounda M, Eggenspiller A, Gros CP, Lachkar M, Barbe JM, Fukuzumi S. Efficient Photoinduced Electron Transfer in a Porphyrin Tripod−Fullerene Supramolecular Complex via π−π Interactions in Nonpolar Media. J Am Chem Soc 2010; 132:4477-89. [DOI: 10.1021/ja100192x] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Atsuro Takai
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, ICMUB, UMR CNRS 5260, Université de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France, Université Sidi Mohamed Ben Abdellah, Faculté des Sciences Dhar El Mahraz, Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires “L.I.M.O.M.”, Département de Chimie
| | - Mohammed Chkounda
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, ICMUB, UMR CNRS 5260, Université de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France, Université Sidi Mohamed Ben Abdellah, Faculté des Sciences Dhar El Mahraz, Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires “L.I.M.O.M.”, Département de Chimie
| | - Antoine Eggenspiller
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, ICMUB, UMR CNRS 5260, Université de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France, Université Sidi Mohamed Ben Abdellah, Faculté des Sciences Dhar El Mahraz, Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires “L.I.M.O.M.”, Département de Chimie
| | - Claude P. Gros
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, ICMUB, UMR CNRS 5260, Université de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France, Université Sidi Mohamed Ben Abdellah, Faculté des Sciences Dhar El Mahraz, Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires “L.I.M.O.M.”, Département de Chimie
| | - Mohammed Lachkar
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, ICMUB, UMR CNRS 5260, Université de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France, Université Sidi Mohamed Ben Abdellah, Faculté des Sciences Dhar El Mahraz, Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires “L.I.M.O.M.”, Département de Chimie
| | - Jean-Michel Barbe
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, ICMUB, UMR CNRS 5260, Université de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France, Université Sidi Mohamed Ben Abdellah, Faculté des Sciences Dhar El Mahraz, Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires “L.I.M.O.M.”, Département de Chimie
| | - Shunichi Fukuzumi
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, ICMUB, UMR CNRS 5260, Université de Bourgogne, 9 Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France, Université Sidi Mohamed Ben Abdellah, Faculté des Sciences Dhar El Mahraz, Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires “L.I.M.O.M.”, Département de Chimie
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Azhdari Tehrani A, Mir Mohammad Sadegh B, Khavasi HR. catena-Poly[[bis-(pyrazine-2-carbox-amide)mercury(II)]-di-μ-chlorido]. Acta Crystallogr Sect E Struct Rep Online 2010; 66:m261. [PMID: 21580214 PMCID: PMC2983533 DOI: 10.1107/s1600536810003879] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Accepted: 02/01/2010] [Indexed: 11/10/2022]
Abstract
In the polymeric title compound, [HgCl2(C5H5N3O)2]n, the HgII atom (site symmetry ) adopts a distorted trans-HgN2Cl4 octahedral coordination geometry. In the crystal, adjacent mercury ions are bridged by pairs of chloride ions, generating infinite [100] chains, and N—H⋯O and N—H⋯(N,N) hydrogen bonds help to consolidate the packing.
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Mir Mohammad Sadegh B, Azhdari Tehrani A, Khavasi HR. catena-Poly[[bis-(pyrazine-2-carbox-amide-κN)mercury(II)]-di-μ-bromido]. Acta Crystallogr Sect E Struct Rep Online 2010; 66:m158. [PMID: 21579633 PMCID: PMC2979956 DOI: 10.1107/s1600536810001182] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2010] [Accepted: 01/10/2010] [Indexed: 11/25/2022]
Abstract
In the crystal structure of the title compound, [HgBr2(C5H5N3O)2]n, the HgII cation is located on an inversion center and is coordinated by two N atoms from the pyrazine rings and four bridging Br− anions in a distorted octahedral geometry. The Br− anions bridge the HgII cations with significantly different Hg—Br bond distances of 2.4775 (8) and 3.1122 (8) Å, forming polymeric chains running along the a axis. Intermolecular N—H⋯O and N—H⋯N hydrogen bonds are effective in the stabilization of the crystal structure.
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Kojima T, Inui Y, Miyazaki S, Shiro M, Fukuzumi S. A tetranuclear iridium(iii) complex with a flavin analogue as a bridging ligand in different coordination modes and exchangeable anion encapsulation in a supramolecular cage. Chem Commun (Camb) 2009:6643-5. [DOI: 10.1039/b911033j] [Citation(s) in RCA: 6] [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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Fukuzumi S, Kojima T. Control of redox reactivity of flavin and pterin coenzymes by metal ion coordination and hydrogen bonding. J Biol Inorg Chem 2008; 13:321-33. [DOI: 10.1007/s00775-008-0343-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Accepted: 01/11/2008] [Indexed: 11/30/2022]
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Miyazaki S, Kojima T, Fukuzumi S. Photochemical and Thermal Isomerization of a Ruthenium(II)−Alloxazine Complex Involving an Unusual Coordination Mode. J Am Chem Soc 2008; 130:1556-7. [DOI: 10.1021/ja077954a] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Soushi Miyazaki
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan
| | - Takahiko Kojima
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan
| | - Shunichi Fukuzumi
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan
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24
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Miyazaki S, Kojima T, Sakamoto T, Matsumoto T, Ohkubo K, Fukuzumi S. Proton-Coupled Electron Transfer in Ruthenium(II)−Pterin Complexes: Formation of Ruthenium-Coordinated Pterin Radicals and Their Electronic Structures. Inorg Chem 2007; 47:333-43. [DOI: 10.1021/ic701759c] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Soushi Miyazaki
- Department of Material and Life Science, Graduate School of Engineering, Osaka University and SORST (JST), Suita, Osaka 565-0871 and Department of Chemistry, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-Ku, Fukuoka 812-8581, Japan
| | - Takahiko Kojima
- Department of Material and Life Science, Graduate School of Engineering, Osaka University and SORST (JST), Suita, Osaka 565-0871 and Department of Chemistry, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-Ku, Fukuoka 812-8581, Japan
| | - Taisuke Sakamoto
- Department of Material and Life Science, Graduate School of Engineering, Osaka University and SORST (JST), Suita, Osaka 565-0871 and Department of Chemistry, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-Ku, Fukuoka 812-8581, Japan
| | - Tetsuya Matsumoto
- Department of Material and Life Science, Graduate School of Engineering, Osaka University and SORST (JST), Suita, Osaka 565-0871 and Department of Chemistry, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-Ku, Fukuoka 812-8581, Japan
| | - Kei Ohkubo
- Department of Material and Life Science, Graduate School of Engineering, Osaka University and SORST (JST), Suita, Osaka 565-0871 and Department of Chemistry, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-Ku, Fukuoka 812-8581, Japan
| | - Shunichi Fukuzumi
- Department of Material and Life Science, Graduate School of Engineering, Osaka University and SORST (JST), Suita, Osaka 565-0871 and Department of Chemistry, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-Ku, Fukuoka 812-8581, Japan
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25
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Su F, Lv L, Lee FY, Liu T, Cooper AI, Zhao XS. Thermally reduced ruthenium nanoparticles as a highly active heterogeneous catalyst for hydrogenation of monoaromatics. J Am Chem Soc 2007; 129:14213-23. [PMID: 17973376 DOI: 10.1021/ja072697v] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report here a thermal reduction method for preparing Ru catalysts supported on a carbon substrate. Mesoporous SBA-15 silica, surface-carbon-coated SBA-15, templated mesoporous carbon, activated carbon, and carbon black with different pore structures and compositions were employed as catalyst supports to explore the versatility of the thermal reduction method. Nitrogen adsorption, X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy, thermogravimetric analysis, and X-ray absorption near-edge structure techniques were used to characterize the samples. It was observed that carbon species that could thermally reduce Ru species at high temperatures played a vital role in the reduction process. Ru nanoparticles supported on various carbon-based substrates exhibited good dispersion with an appropriate particle size, high crystallinity, strong resistance against oxidative atmosphere, less leaching, lack of aggregation, and avoidance of pore blocking. As such, these catalysts display a remarkably high catalytic activity and stability in the hydrogenation of benzene and toluene (up to 3-24-fold compared with Ru catalysts prepared by traditional methods). It is believed that the excellent catalytic performance of the thermally reduced Ru nanoparticles is related to the intimate interfacial contact between the Ru nanoparticles and the carbon support.
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Affiliation(s)
- Fabing Su
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576.
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26
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Kojima T, Hayashi KI, Iizuka SY, Tani F, Naruta Y, Kawano M, Ohashi Y, Hirai Y, Ohkubo K, Matsuda Y, Fukuzumi S. Synthesis and Characterization of Mononuclear Ruthenium(III) Pyridylamine Complexes and Mechanistic Insights into Their Catalytic Alkane Functionalization withm-Chloroperbenzoic Acid. Chemistry 2007; 13:8212-22. [PMID: 17625799 DOI: 10.1002/chem.200700190] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A series of mononuclear RuIII complexes [RuCl2(L)]+, where L is tris(2-pyridylmethyl)amine (TPA) or one of four TPA derivatives as tetradentate ligand, were prepared and characterized by spectroscopic methods, X-ray crystallography, and electrochemical measurements. The geometry of a RuIII complex having a non-threefold-symmetric TPA ligand bearing one dimethylnicotinamide moiety was determined to show that the nicotine moiety resides trans to a pyridine group, but not to the chlorido ligand. The substituents of the TPA ligands were shown to regulate the redox potential of the ruthenium center, as indicated by a linear Hammett plot in the range of 200 mV for RuIII/RuIV couples with a relatively large rho value (+0.150). These complexes act as effective catalysts for alkane functionalization in acetonitrile with m-chloroperbenzoic acid (mCPBA) as terminal oxidant at room temperature. They exhibited fairly good reactivity for oxidation of cyclohexane (C--H bond energy 94 kcal mol(-1)), and the reactivity can be altered significantly by the electronic effects of substituents on TPA ligands in terms of initial rates and turnover numbers. Catalytic oxygenation of cyclohexane by a RuIII complex with 16O-mCPBA in the presence of H2 18O gave 18O-labeled cyclohexanol with 100% inclusion of the 18O atom from the water molecule. Resonance Raman spectra under catalytic conditions without the substrate indicate formation of a RuIV==O intermediate with lower bonding energy. Kinetic isotope effects (KIEs) in the oxidation of cyclohexane suggest that hydrogen abstraction is the rate-determining step and the KIE values depend on the substituents of the TPA ligands. Thus, the reaction mechanism of catalytic cyclohexane oxygenation depends on the electronic effects of the ligands.
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Affiliation(s)
- Takahiko Kojima
- Department of Chemistry, Faculty of Sciences, Kyushu University, Hakozaki, Higashi-Ku, Fukuoka 812-8581, Japan.
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