We report the first example of a mononuclear nonheme manganese(III)-hydroperoxo complex derived from protonation of an isolated manganese(III)-peroxo complex bearing an N-tetramethylated cyclam (TMC) ligand, [Mn(III)(TMC)(OOH)](2+). The Mn(III)-hydroperoxo intermediate is characterized with various spectroscopic methods as well as with density functional theory (DFT) calculations, showing the b...

Manganese peroxidase (MnP) is an extracellular heme enzyme that catalyzes the peroxide-dependent oxidation of Mn(II) to Mn(III). The Mn(III) is released from the enzyme in complex with oxalate. One heme propionate and the side chains of Glu35, Glu39, and Asp179 were identified as Mn(II) ligands in the 2.0 A resolution crystal structure. The new 1.45 A crystal structure of MnP complexed with Mn(...

High initial Mn(II) concentration results in accumulation of a Mn(III) tartrate complex in the growth medium of Phanerochaete chrysosporium. Since Mn(III) is the major oxidant in ligninolysis by manganese peroxidase, the role of accumulated complex should not be neglected when degradation experiments by a crude culture filtrate are performed. To study the Mn(III) complex oxidative potential it ...

Based-on the quasi-planar tetra-dentate Schiff-base ligand, a pair of manganese(III) Schiff-base enantiomers formulated as {[Mn(R,R-3-MeOSalcy)(H2O)(CH3OH)]ClO4}2 (1) and {[Mn(S,S-3-MeOSalcy)(H2O)(CH3OH)]ClO4}2 (2) (3-MeOSalcy = N,N′-(1,2-cyclohexanediylethylene)bis(3-methoxysalicylideneiminato)dianion) ...

The dimeric complex [Mn(III)(2)(Naphth-sao)(2)(Naphth-saoH)(2)(MeOH)(2)]·4MeOH (1·4MeOH), acts as a simple model complex with which to examine the magneto-structural relationship in polymetallic, oxime-bridged Mn(III) complexes. Dc magnetic susceptibility studies reveal that ferromagnetic exchange is mediated through the heavily twisted Mn-O-N-Mn moiety (J = +1.24 cm(-1)) with magnetisation mea...

A new high oxidation state Mn(III/IV)(11) carboxylate complex has been prepared and then converted to a Mn(II/III)(25) azide/carboxylate cluster with Me(3)SiN(3); the Mn(25) product is the initial example of a higher oxidation state Mn azide complex not stabilized by any chelate ligands.

A salophen cobalt(II) complex enables water oxidation at neutral pH in photoactivated sacrificial cycles under visible light, thus confirming the high appeal of earth abundant single site catalysis for artificial photosynthesis.

The title compound, [Co(C(20)H(14)N(2)O(2))(C(5)H(5)N)(2)]ClO(4) or [Co(salophen)(py)(2)]ClO(4), where salophen is o-phenyl-enebis(nitrilo-methyl-idyne)]diphenolate and py is pyridine, contains a six-coordinate mononuclear cobalt(III) atom. The two phenolic O atoms and the two imine N atoms are located in cis positions. There are two pyridine mol-ecules attached to the metal atom, filling the a...

Manganese (Mn)-induced neurodegenerative toxicity has been associated with a distorted iron (Fe) metabolism at both systemic and cellular levels. In the current study, we examined whether the oxidation states of Mn produced differential effects on certain mitochondrial [Fe-S] containing enzymes in vitro. When mitochondrial aconitase, which possesses a [4Fe-4S] cluster, was incubated with either...