The capabilities and limitations of the Becke-3-Lee-Yang-Parr (B3LYP) density functional theory (DFT) for modeling proton coupled electron transfer (PCET) in the mixed-valence oxomanganese complex 1 [(bpy)(2)Mn(III)(mu-O)(2)Mn(IV)(bpy)(2)](3+) (bpy = 2,2'-bipyridyl) are analyzed. Complex 1 serves as a prototypical synthetic model for studies of redox processes analogous to those responsible for...

A series of metallosalen-based metal-organic frameworks (MOFs) have been prepared by the post-synthesis modification of Mn(III)SO-MOF, a Mn(3+)(salen)-based MOF. Treatment of Mn(III)SO-MOF with H(2)O(2) effects the removal of the Mn(3+) ions from the salen struts, which can then be remetalated with a variety of metal precursors to form isostructural MSO-MOF materials. The presence of the new me...

The Complexes of Ti(iii), V(iii), Mn(iii), Co(iii), Ru(iii), Ru(ii), MoO(v), Fe(iii), MoO 2 (vi) and UO 2 (vi) with S-benzyl-β-N-(2-hydroxy-5-bromophenyl) methylendithiocarbazate have been synthesized and characterised by melting points, molar conductance,magnetic susceptibility, electronic and IR spectral studies. The complexes of Ti(iii), V(iii), Mn(iii), Ru(iii) & MoO(v) are paramagnetic whi...

The synthesis and crystal structure for the title compound, [YNaMn4(C7H4NO3)4(C5H9O2)4(H2O)3.76(C3H7NO)0.24]·8.04C3H7NO·0.62H2O or [Y(III)Na(OTMA)4[12-MCMn(III)N(shi)-4](H2O)3.76(DMF)0.24·8.04DMF·0.62H2O, where OTMA is tri-methyl-acetate, MC is metallacrown, shi(3-) is salicyl-hydroximate, and DMF is N,N-di-methyl-formamide, is reported. The macrocyclic metallacrown consists of an -[Mn(III)-N-O...

The significant enhancement of acidic potassium permanganate chemiluminescence by Mn(II) results from the concomitant presence of permanganate and Mn(III) in the reagent solution, which enables rapid production of the excited Mn(II) emitter with a wide range of analytes. Furthermore, the key Mn(III) co-reactant can be quickly generated by reducing permanganate with sodium thiosulfate, instead o...

The comproportionation reaction between Mn(II) and Mn(VII) reagents under acidic conditions has been investigated in the presence of pivalic acid as a route to new high oxidation state manganese pivalate clusters containing some Mn(IV). The reaction of Mn(O(2)CBu(t))(2) and NBu(n)(4)MnO(4) with an excess of pivalic acid in the presence of Mn(ClO(4))(2) and NBu(n)(4)Cl in hot MeCN led to the iso...

Abstract manganese lipoxygenase (Mn-LO) oxygenates 18:3n-3 and 18:2n-6 to bis-allylic 11S-hydroperoxy fatty acids, which are converted to 13R-hydroperoxy fatty acids. Other unsaturated C(16)-C(22) fatty acids, except 17:3n-3, are poor substrates, possibly because of ineffective enzyme activation (Mn(II)-->Mn(III)) by the produced hydroperoxides. Our aim was to determine whether unsaturated C(16...

Density functional theory is used to explore possible mechanisms that lead to water oxidation by a bimetallic manganese catalyst developed by McKenzie and co-workers. On the basis of our calculations we propose that the key active intermediate is a mixed valent Mn(III)(μ-O)Mn(IV)-O˙ oxyl radical species, the oxyl centre being the site of nucleophilic attack by water. The mixed-valent species is...

Evidence has recently been presented that photoinhibition of photosystem II (PSII) is triggered by absorption of light by the oxygen-evolving manganese cluster. To get insight into the effects of light on enzymes containing manganese or other transition metal cofactors, the photosensitivities of Mn catalase, Mn superoxide dismutase, the haem (Fe)-containing bovine liver catalase, and CuZn super...