Binuclear Manganese Research Articles

Effect of anions and redox state on the activity of manganese containing catalase from Thermus thermophilus

Catalase isolated from thermophilic bacterium Thermus thermophilus (Mn-catalase) is composed of six subunits, each containing binuclear manganese clusters at their active site. The enzyme is active when the metal is in the completely reduced (Mn 2+Mn 2+) state in the pH range 7–10, and loses activity on oxidation. ESR data suggest that the metal turns thereby into the (Mn 2+Mn 4+) state. The Mn-catalase activity is inhibited by chloride, nitrate, nitrite, azide, and other singly charged anions, except cyanide. The inhibitory effect of anions increases as the pH value is reduced. The inhibition by hydroxylamine takes place through a lag-phase and is weakly dependent on pH value. The reaction mechanism is discussed in relation with current concepts of catalase reactions of heme-proteins and low-molecular binuclear manganese complexes.

The stereospecific synthesis of mono- and bi-nuclear (ligand-bridged) carbonyl complexes of manganese: a review

A review is given of the routes that can be used to give the different isomeric forms of mono- and bi-nuclear manganese carbonyl complexes of the general types [Mn(CO) 4− n ( L L )L n ] + and [L n ( L L )(CO) 3− n Mn-X-Mn(CO) 3− m ( L L )′ L′ m ] +, where L L are chelating bidentate ligands and X is a bridging ligand.

Binuclear manganese(II) and nickel(II) complexes with a potentially octadentate macrocyclic ligand (H 4L1): synthesis and characterisation. X-ray crystal structures of [Mn 2(H 2L1 )(CH 3COO) 2]·2CH 3OH and [Ni 2(H 2L1 )(H 2O) 2Cl 2]·2H 20

A series of binuclear manganese(II) and nickel(II) complexes of the macrocyctic ligand H 4L1 has been prepared and characterised. ([Mn 2(H 2L1)A 2], where A=Cl −, Br −, NO 3 −, NCS −, CH 3COO − or N 3 −; [Ni 2(H 2L1)X 2Y 2], where X=Cl −, Br − or NO 3 − and Y= H 20, [Ni 2(H 2L1)(NCS) 2(C 2H 5OH)] and [Ni 2(H 2L1)(CH 3COO) 2]·2H 2O). The macrocycle is formed by Schiff base condensation of two molecules of 2,6-diformyl-4-methylphenol with two molecules of 1,3-diamino-2-hydroxypropane in the presence of Ni(lI) or Mn(II) as template ion. The complexes are all binuclear with the two metal ions bridged by the deprotonated phenolate donors of the macrocycle. The alcohol groups of the macrocyclic ligand do not coordinate to the metal ions. The complexes have been characterised by analytical, spectroscopic, electrochemical and magnetic susceptibility measurements and the single crystal X-ray structures of [Mn 2(H 2L1)(CH 3COO) 2]·2CH 3OH (triclinic, P 1 , a=8.701, b= 10.258, c=10.612 Å, α=62.44, β=67.83, γ= 77.74°, V=776.8 Å 3, Z=1) and of [Ni 2(H 2L1)(H 2O) 2Cl 2]·2H 2O (rhombohedral, R 3 , a=28.885, c=9.783 Å, V=7069 Å 3, Z=9) have been determined.

Synthesis, Structures, and Magnetic Properties of Novel Binuclear and Mononuclear Manganese(II) Complexes with 2,6-Bis[N-(2-pyridylethyl)iminomethyl]-4-methylphenol

Abstract Binuclear and mononuclear manganese(II) complexes with 2,6-bis[N-(2-pyridylethyl)iminomethyl]-4-methylphenol (HL), [Mn2(L)(CH3COO)2(NCS)] and [Mn(HL)(NCS)2(H2O)], have been prepared and characterized by X-ray structure analyses, magnetic susceptibilities (80–300 K), and EPR spectrum.

Syntheses and characterization of binuclear manganese(III,IV) and -(IV,IV) complexes with ligands related to tris(2-pyridylmethyl)amine

Syntheses and characterization of binuclear manganese(III,IV) and -(IV,IV) complexes with ligands related to tris(2-pyridylmethyl)amine

Evidence that protein B of the thiosulphate-oxidizing system of Thiobacillus versutus contains a binuclear manganese cluster

Manganese was shown to be an essential trace metal for growth and thiosulphate oxidation by Thiobacillus versutus in chemostat culture. In the thiosulphate-oxidizing enzyme system of T. versutus, protein B was the only component found to contain manganese in significant amounts. When it was examined by electron spin resonance (ESR) spectroscopy, protein B gave a broad, complex spectrum, indicative of the presence of a dimeric manganese cluster, with manganese in the Mn(II) oxidation state.

Epoxidation of olefins by iodosylbenzene catalyzed by binuclear copper, cobalt and manganese complexes

Epoxidation of olefins by iodosylbenzene catalyzed by binuclear copper, cobalt and manganese complexes

A binuclear manganese(II) complex with 2,6-bis[ N-(2-pyridylethyl)iminomethyl]-4-methylphenol

A binuclear manganese(II) complex with 2,6-bis[ N-(2-pyridylethyl)iminomethyl]-4-methylphenol

Methods for analysis of the mononuclear and binuclear manganese(III) cyano-complexes

Simple titrimetric methods are described for the analysis of potassium hexacyanomanganate(III) and of heptapotassium μ-oxo-bis[pentacyanomanganate(III)] cyanide. Mn 2O(CN) 6− 10 is determined by potentiometric titration with hexacyanoferrate(III). Cyanide is determined in both complexes by back-titration with Hg(II) and SCN −, and manganese(III) is determined by back-titration with Fe(II) and MnO − 4. The absorption spectra of both cyano-complexes in cyanide and in acidic solutions are also described, and their molar absorptivities are reported.

ChemInform Abstract: Synthesis and Characterization of a Mixed‐Valence Binuclear Manganese(II,III) Complex of a Septadentate Polyimidazole Ligand.

AbstractThe Mn(II,III) complex (I) is obtained by reaction of Mn(III) acetate with the septadentate ligand 2,6‐bis(bis((1‐methylimidazol‐2‐yl)methyl)aminomethyl)‐4‐methylphenol and NaClO4 in methanol.

Importance of intermediate charge-transfer complex formation in the model reaction for laccase

The catalytic activities of binuclear copper(II), cobalt(II) and manganese(II) complexes with 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenol were compared for the oxidation reaction of N, N, N′, N′-tetramethyl- p-phenylenediamine by dioxygen molecules. The highest activity was observed for the copper(II) complex, supporting the importance of intermediate charge-transfer complex formation in the reaction.

Crystal Structure and Magnetic Property of the Binuclear Manganese(III) Complex with μ-Acetate and Di-μ-Alkoxo Bridges

Abstract Binuclear manganese(III) complex, [Mn2L(μ-OCH3)(μ-CH3COO)(OHCH3)]ClO4 was pre­pared and characterized in terms of crystal structure determination, magnetic measurement, and ESR spectroscopy, where H3L represents the Schiff base derived from salicylaldehyde and 1,5- diamino-3-pentanol.

On the frozen solution ESR spectra of binuclear manganese(III) complexes with oxo and acetate bridges

We have observed that the acetonitrile frozen solution ESR spectra(77 K) of binuclear manganese(III) complexes with oxo and acetate bridges exhibit a “16-line ESR signal,” and this has been attributed to the dimeric Mn(III)-Mn(III) pair.

Synthesis and characterization of binuclear manganese complexes: redox models for the water oxidation cofactor of photosystem II

Synthesis and characterization of binuclear manganese complexes: redox models for the water oxidation cofactor of photosystem II

ChemInform Abstract: Mn2+/Mn3+ and Mn3+/Mn4+ Mixed Valence Binuclear Manganese Complexes of Biological Interest.

AbstractThe tetraphenylporphyrin ligand forms stable complexes with Mn2+, Mn3+, and Mn4+.

Synthesis and characterization of a mixed-valence binuclear manganese(II,III) complex of a septadentate polyimidazole ligand

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and characterization of a mixed-valence binuclear manganese(II,III) complex of a septadentate polyimidazole ligandRobert M. Buchanan, Kenneth J. Oberhausen, and John F. RichardsonCite this: Inorg. Chem. 1988, 27, 6, 971–973Publication Date (Print):March 1, 1988Publication History Published online1 May 2002Published inissue 1 March 1988https://doi.org/10.1021/ic00279a004RIGHTS & PERMISSIONSArticle Views155Altmetric-Citations46LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (425 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Preparation and Structural Characterization of Binuclear Manganese(III) Complexes with 1,5-Bis(salicylideneamino)-3-pentanol and Its Derivatives

Abstract Three binuclear manganese(III) complexes with the title Schiff base ligands have been prepared and characterized. X-Ray structure analysis of [Mn2(Lb) (CH3O) (CH3COO) (CH3OH) (ClO4)] (H3Lb = 1,5-bis(5-chlorosalicylideneamino)-3-pentanol) has revealed that the two manganese ions are bridged by the alkoxide oxygen atom of the Schiff base ligand, the methoxide oxygen atom, and the oxygen atoms of the acetate ion with the Mn–Mn separation of 2.921(2) Å.

Preparation and Crystal Structure of Binuclear Manganese(II) Complex Exhibiting Multiline ESR Signal

Abstract Binuclear manganese(II) complex with 2-[bis(2-pyridylmethyl)aminomethyl]-4-nitrophenol, which exhibits a multiline ESR signal, was prepared, and its crystal structure was determined by X-ray diffraction method.

Mn2+/Mn3+ and Mn3+/Mn4+ mixed valence binuclear manganese complexes of biological interest

Binuclear and multinuclear manganese containing enzymes which occur in biology are involved in functions such as hydrogen peroxide decomposition in bacteria and the oxidation of water to oxygen during photosynthesis, respectively. In the case of the water-oxidizing complex, the so-called S/sub 2/ oxidation state has been characterized by EPR spectroscopy to be a mixed valence manganese cluster. This can be produced in two forms. The native form, which is found in active O/sub 2/-evolving samples, is considered to be either tetranuclear or trinuclear in Mn, based upon interpretation of its broad 1500 G-wide 19-line multiline EPR signal and unusual temperature dependence. A partially decoupled form is found in inactivated samples having a narrow width (1345 G), with only 16 lines and a more Curie-like temperature dependence, all features which are found in typical Mn/sup 3 +//M/sup 4 +/ binuclear centers (16-line EPR, spin S = 1/2 ground state). For the native form both different oxidation states and different numbers for the manganese ions in the cluster have been proposed in order to account for the larger spectral width due to the hyperfine interaction with /sup 55/Mn. Both binuclear Mn/sup 2 +//Mn/sup 3 +/ and tetranuclear/sup 4/ 3Mn/sup 3 +//Mn/sup 4more » +/ states have been considered. Notably lacking in this analysis has been EPR data for binuclear complexes in which both types of mixed valence oxidation states, Mn/sup 3 +//Mn/sup 4 +/ and Mn/sup 2 +//Mn/sup 3 +/, are compared within the same ligand system. The present report gives the first experimental evidence showing how /sup 55/Mn hyperfine data can easily distinguish between binuclear manganese complexes having these mixed valence oxidation states.« less

Kinetics and mechanism of the reduction of polychloroalkanes by triethylsilane, catalyzed by binuclear manganese and rhenium carbonyls

1. Kinetic methods have been used to show that the hydrides HM(CO)5 formed in the systems M2(CO)10 + HSiEt3 (M=Mn and Re) are involved in chain transfer at the chlorinated radicals. 2. The formation of HRe(CO)5 in the photochemical reaction of Re2(CO)10 with HSiEt3 has been shown by UV spectroscopy. 3. The system Mn2(CO)10 + HSiEt3 has been shown for the first time to be capable or reducing 1,1-dichloroalkanes.