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Balamurugan M, Vadivelu P, Palaniandavar M. Iron(iii) complexes of tripodal tetradentate 4N ligands as functional models for catechol dioxygenases: the electronic vs. steric effect on extradiol cleavage. Dalton Trans 2014; 43:14653-68. [DOI: 10.1039/c3dt52145a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Models for enzyme–substrate adduct of non-heme iron-containing enzymes, synthesis and characterization. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2013.06.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Karimpour T, Safaei E, Wojtczak A, Jagličić Z, Kozakiewicz A. Iron(III) complexes of ethylenediamine derivatives of aminophenol ligands as models for enzyme–substrate adducts of catechol dioxygenases. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2012.10.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Visvaganesan K, Ramachitra S, Palaniandavar M. Functional models for enzyme–substrate adducts of catechol dioxygenase enzymes: The Lewis basicity of facially coordinating tridentate phenolate ligands tunes the rate of dioxygenation and product selectivity. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.08.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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PALANIANDAVAR MALLAYAN, VISVAGANESAN KUSALENDIRAN. Mononuclear non-heme iron(III) complexes of linear and tripodal tridentate ligands as functional models for catechol dioxygenases: Effect of N-alkyl substitution on regioselectivity and reaction rate. J CHEM SCI 2011. [DOI: 10.1007/s12039-011-0110-7] [Citation(s) in RCA: 7] [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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Anitha N, Palaniandavar M. Mononuclear iron(iii) complexes of 3N ligands in organized assemblies: spectral and redox properties and attainment of regioselective extradiol dioxygenase activity. Dalton Trans 2011; 40:1888-901. [DOI: 10.1039/c0dt01012j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sundaravel K, Sankaralingam M, Suresh E, Palaniandavar M. Biomimetic iron(iii) complexes of N3O and N3O2 donor ligands: protonation of coordinated ethanolate donor enhances dioxygenase activity. Dalton Trans 2011; 40:8444-58. [PMID: 21785763 DOI: 10.1039/c1dt10495k] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Karuppasamy Sundaravel
- Centre for Bioinorganic Chemistry, School of Chemistry, Bharathidasan University, Tiruchirappalli, 620 024, India
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Sundaravel K, Suresh E, Saminathan K, Palaniandavar M. Iron(III) complexes of N2O and N3O donor ligands as functional models for catechol dioxygenase enzymes: ether oxygen coordination tunes the regioselectivity and reactivity. Dalton Trans 2011; 40:8092-107. [DOI: 10.1039/c0dt01598a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Karuppasamy Sundaravel
- Centre for Bioinorganic Chemistry, School of Chemistry, Bharathidasan University, Tiruchirappalli, 620 024, Tamilnadu, India
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Sundaravel K, Suresh E, Palaniandavar M. Iron(III) complexes of tridentate N3 ligands as models for catechol dioxygenases: Stereoelectronic effects of pyrazole coordination. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2010.04.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Mayilmurugan R, Sankaralingam M, Suresh E, Palaniandavar M. Novel square pyramidal iron(iii) complexes of linear tetradentate bis(phenolate) ligands as structural and reactive models for intradiol-cleaving 3,4-PCD enzymes: Quinone formation vs. intradiol cleavage. Dalton Trans 2010; 39:9611-25. [DOI: 10.1039/c0dt00171f] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Dhanalakshmi T, Suresh E, Palaniandavar M. Synthesis, structure, spectra and reactivity of iron(III) complexes of imidazole and pyrazole containing ligands as functional models for catechol dioxygenases. Dalton Trans 2009:8317-28. [PMID: 19789784 DOI: 10.1039/b903602d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of new 1 : 1 iron(iii) complexes of the type [Fe()Cl(3)], where is a tridentate 3N donor ligand, has been isolated and studied as functional models for catechol dioxygenases. The ligands (1-methyl-1H-imidazol-2-ylmethyl)pyrid-2-ylmethyl-amine (), N,N-dimethyl-N'-(1-methyl-1H-imidazol-2-ylmethyl)ethane-1,2-diamine () and N-(1-methyl-1H-imidazol-2-ylmethyl)-N'-phenylethane-1,2-diamine () are linear while the ligands tris(1-pyrazolyl)methane (), tris(3,5-dimethyl-1-pyrazolyl)methane () and tris(3-iso-propylpyrazolyl)methane () are tripodal ones. All the complexes have been characterized by spectral and electrochemical methods. The X-ray crystal structure of the dinuclear catecholate adduct [Fe()(TCC)](2)O, where TCC(2-) is a tetrachlorocatecholate dianion, has been successfully determined. In this complex both the iron(iii) atoms are bridged by a mu-oxo group and each iron(iii) center possesses a distorted octahedral coordination geometry in which the ligand is facially coordinated and the remaining coordination sites are occupied by the TCC(2-) dianion. Spectral studies suggest that addition of a base like Et(3)N induces the mononuclear complex species [Fe()(TCC)Cl] to dimerize forming a mu-oxo-bridged complex. The spectral and electrochemical properties of the catecholate adducts of the complexes generated in situ reveal that a systematic variation in the ligand donor atom type significantly influences the Lewis acidity of the iron(iii) center and hence the interaction of the complexes with simple and substituted catechols. The 3,5-di-tert-butylcatecholate (DBC(2-)) adducts of the type [Fe()(DBC)Cl], where is a linear tridentate ligand (), undergo mainly oxidative intradiol cleavage of the catechol in the presence of dioxygen. Also, the extradiol-to-intradiol product selectivity (E : I) is enhanced upon removal of the coordinated chloride ion in these adducts to obtain [Fe()(DBC)(Sol)](+) and upon incorporating coordinated N-methylimidazolyl nitrogen in them. In contrast to the iron(iii) complexes of imidazole-based ligands, those of the tripodal pyrazole-based ligands yield major amounts of the oxidized product benzoquinone and small amounts of both intra- and extradiol products. One of the pyrazole arms coordinated in the equatorial plane of these sterically constrained complexes is substituted by a solvent molecule upon adduct formation with DBC(2-), which encourages molecular oxygen to attack this site leading to benzoquinone formation. The DBSQ/DBC(2-) redox potentials of both the imidazole- and pyrazole-based complexes fall in the narrow range of -0.186 to -0.214 V supporting this proposal.
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Mayilmurugan R, Visvaganesan K, Suresh E, Palaniandavar M. Iron(III) Complexes of Tripodal Monophenolate Ligands as Models for Non-Heme Catechol Dioxygenase Enzymes: Correlation of Dioxygenase Activity with Ligand Stereoelectronic Properties. Inorg Chem 2009; 48:8771-83. [DOI: 10.1021/ic900969n] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Eringathodi Suresh
- Analytical Science Discipline, Central Salt and Marine Chemicals Research Institute, Bhavnagar − 364 002, India
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Mayilmurugan R, Stoeckli-Evans H, Palaniandavar M. Novel Iron(III) Complexes of Sterically Hindered 4N Ligands: Regioselectivity in Biomimetic Extradiol Cleavage of Catechols. Inorg Chem 2008; 47:6645-58. [DOI: 10.1021/ic702410d] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ramasamy Mayilmurugan
- School of Chemistry, Bharathidasan University, Tiruchirapalli 620 024, India, and Department of Chemistry, University of Neuchatel, Neuchatel, Switzerland
| | - Helen Stoeckli-Evans
- School of Chemistry, Bharathidasan University, Tiruchirapalli 620 024, India, and Department of Chemistry, University of Neuchatel, Neuchatel, Switzerland
| | - Mallayan Palaniandavar
- School of Chemistry, Bharathidasan University, Tiruchirapalli 620 024, India, and Department of Chemistry, University of Neuchatel, Neuchatel, Switzerland
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Sundaravel K, Dhanalakshmi T, Suresh E, Palaniandavar M. Synthesis, structure, spectra and reactivity of iron(iii) complexes of facially coordinating and sterically hindering 3N ligands as models for catechol dioxygenases. Dalton Trans 2008:7012-25. [DOI: 10.1039/b809142k] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Visvaganesan K, Mayilmurugan R, Suresh E, Palaniandavar M. Iron(III) Complexes of Tridentate 3N Ligands as Functional Models for Catechol Dioxygenases: The Role of Ligand N-alkyl Substitution and Solvent on Reaction Rate and Product Selectivity. Inorg Chem 2007; 46:10294-306. [DOI: 10.1021/ic700822y] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kusalendiran Visvaganesan
- School of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, India, Analytical Science Discipline, Central Salt and Marine Chemicals Research Institute, Bhavnagar-364 002, India
| | - Ramasamy Mayilmurugan
- School of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, India, Analytical Science Discipline, Central Salt and Marine Chemicals Research Institute, Bhavnagar-364 002, India
| | - Eringathodi Suresh
- School of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, India, Analytical Science Discipline, Central Salt and Marine Chemicals Research Institute, Bhavnagar-364 002, India
| | - Mallayan Palaniandavar
- School of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, India, Analytical Science Discipline, Central Salt and Marine Chemicals Research Institute, Bhavnagar-364 002, India
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Kanamori K, Kusajima K, Yachi H, Suzuki H, Miyashita Y, Okamoto KI. Synthesis, X-ray Structures, and Solution Properties of Vanadium(III) and -(IV) Complexes withN-(2-Hydroxyphenyl)-N-(2-pyridylmethyl)amine. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.324] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Electron spray ionization mass study on dioxygenation process in the reaction of catecholatoiron(III) complexes with molecular oxygen. Inorganica Chim Acta 2005. [DOI: 10.1016/j.ica.2005.05.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Velusamy M, Mayilmurugan R, Palaniandavar M. Functional models for catechol dioxygenases: Iron(III) complexes of cis-facially coordinating linear 3N ligands. J Inorg Biochem 2005; 99:1032-42. [PMID: 15833326 DOI: 10.1016/j.jinorgbio.2005.01.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Revised: 01/17/2005] [Accepted: 01/18/2005] [Indexed: 11/18/2022]
Abstract
A series of 1:1 iron(III) complexes of simple and sterically hindered tridentate 3N donor ligands have been synthesized and studied as functional models for catechol dioxygenases. All of them are of the type [FeLCl3], where L is bis(pyrid-2-yl-methyl)amine (L1), N,N-bis(benzimidazol-2-ylmethyl)amine (L2), N-methyl-N'-(pyrid-2-ylmethyl)ethylenediamine (L3), N,N-dimethyl-N'-(pyrid-2-ylmethyl)-ethylenediamine (L4) and N-phenyl-N'-(pyrid-2-ylmethyl)ethylenediamine (L5). They have been characterised by spectral and electrochemical methods. The X-ray crystal structure of the complex [Fe(L4)Cl3] has been successfully determined. The complex crystallizes in the triclinic space group P1 with a = 7.250(6), b = 8.284(3), c = 12.409(4) angstroms, alpha = 80.84(3) degrees, beta = 86.76(6) degrees, gamma = 72.09(7) degrees and Z = 2. It possesses a distorted octahedral geometry in which the L4 ligand is cis-facially coordinated to iron(III) and the chloride ions occupy the remaining coordination sites. The systematic variation in the ligand donor atom type significantly influences the Lewis acidity of the iron(III) center and hence the binding interaction of the complexes with simple and substituted catechols. The spectroscopic and electrochemical properties of the catecholate complexes generated in situ have been investigated. All the complexes catalyze mainly the oxidative intradiol cleavage of 3,5-di-tert-butylcatechol (H2DBC) in the presence of dioxygen, which is unexpected of the cis-facial coordination of the ligands. The rate of intradiol catechol cleavage reaction depends upon the Lewis acidity of iron(III) center and steric demand and hydrogen-bonding functionalities of the ligands. Interestingly, the electron-sink property of N-phenyl substituent in [Fe(L5)Cl3] complex leads to enhancement in rate of cleavage. All these observations provide support to the substrate activation mechanism proposed for intradiol-cleaving enzymes.
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Affiliation(s)
- Marappan Velusamy
- Department of Chemistry, Bharathidasan University, Tiruchirappalli 620 024, India
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Velusamy M, Palaniandavar M, Gopalan RS, Kulkarni GU. Novel Iron(III) Complexes of Tripodal and Linear Tetradentate Bis(phenolate) Ligands: Close Relevance to Intradiol-Cleaving Catechol Dioxygenases. Inorg Chem 2003; 42:8283-93. [PMID: 14658880 DOI: 10.1021/ic020569w] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Four new iron(III) complexes of the bis(phenolate) ligands N,N-dimethyl-N',N'-bis(2-hydroxy-3,5-dimethylbenzyl)ethylenediamine [H2(L1)], N,N-dimethyl-N',N'-bis(2-hydroxy-4-nitrobenzyl)ethylenediamine [H2(L2)], N,N'-dimethyl-N,N'-bis(2-hydroxy-3,5-dimethylbenzyl)ethylenediamine [H2(L3)], and N,N'-dimethyl-N,N'-bis(2-hydroxy-4-nitrobenzyl)ethylenediamine [H2(L4)] have been isolated and studied as structural and functional models for the intradiol-cleaving catechol 1,2-dioxygenases (CTD). The complexes [Fe(L1)Cl] (1), [Fe(L2)(H2O)Cl] (2), [Fe(L3)Cl] (3), and [Fe(L4)(H2O)Cl] (4) have been characterized using absorption spectral and electrochemical techniques. The single-crystal X-ray structures of the ligand H2(L1) and the complexes 1 and 2 have been successfully determined. The tripodal ligand H2(L1) containing a N2O2 donor set represents the metal-binding region of the iron proteins. Complex 1 contains an FeN2O2Cl chromophore with a novel trigonal bipyramidal coordination geometry. While two phenolate oxygens and an amine nitrogen constitute the trigonal plane, the other amine nitrogen and chloride ion are located in the axial positions. In contrast, 2 exhibits a rhombically distorted octahedral coordination geometry for the FeN2O3Cl chromophore. Two phenolate oxygen atoms, an amine nitrogen atom, and a water molecule are located on the corners of a square plane with the axial positions being occupied by the other nitrogen atom and chloride ion. The interaction of the complexes with a few monodentate bases and phenolates and differently substituted catechols have been investigated using absorption spectral and electrochemical methods. The effect of substituents on the phenolate rings on the electronic spectral features and FeIII/FeII redox potentials of the complexes are discussed. The interaction of the complexes with catecholate anions reveals changes in the phenolate to iron(III) charge-transfer band and also the appearance of a low-energy catecholate to iron(III) charge-transfer band similar to catechol dioxygenase-substrate complexes. The redox behavior of the 1:1 adducts of the complexes with 3,5-di-tert-butylcatechol (H2DBC) has been also studied. The reactivities of the present complexes with H2DBC have been studied and illustrated. Interestingly, only 2 and 4 catalyze the intradiol-cleavage of H2DBC, the rate of oxygenation being much faster for 4. Also 2, but not 4, yields an extradiol cleavage product. The reactivity of the complexes could be illustrated not on the basis of the Lewis acidity of the complexes alone but by assuming that the product release is the rate-determining phase of the catalytic reaction.
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Affiliation(s)
- Marappan Velusamy
- Department of Chemistry, Bharathidasan University, Tiruchirappalli 620 024, India
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Funabiki T. Functional model oxygenations by nonheme iron complexes. ADVANCES IN CATALYTIC ACTIVATION OF DIOXYGEN BY METAL COMPLEXES 2003. [DOI: 10.1007/0-306-47816-1_4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Novel iron(III) complexes with phenolate containing tripodal tetradentate ligands as model systems for catechol 1,2-dioxygenases. Inorganica Chim Acta 2002. [DOI: 10.1016/s0020-1693(02)01082-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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