High stability of the radical at the catalytic center of cytochrome c oxidase.

In aerobic organisms, cellular respiration is associated with electron transfer through a respiratory system of membrane-bound complexes. This electron flow is terminated by the reduction of dioxygen to water by respiratory oxidases. Cytochrome c oxidase (CcO) is a widely distributed heme-copper-oxygen reductase (HCO) found in all mitochondria and some bacteria.

Structural, optical and magnetic properties of a new metal-organic Co-based complex.

A mononuclear cobalt(ii) complex [CHN][CoCl(CHN)] (I) was synthesized and structurally characterized. Single crystal X-ray diffraction analysis indicates that monometallic Co(ii) ions acted as coordination nodes in a distorted octahedral geometry, giving rise to a supramolecular architecture. The latter is made up of a ½ unit form composed of an anionic element [CoCl(CHN)] and one 2-amino-4-methylpyrimidinium cation [CHN].

Above room temperature spin crossover in mononuclear iron(II) complexes featuring pyridyl-benzimidazole bidentate ligands adorned with aliphatic chains.

Two bidentate ligands (L1 = 1-pentyl-2-(pyridin-2-yl)-1-benzimidazole and L2 = 1-heptyl-2-(pyridin-2-yl)-1-benzimidazole) were employed for the synthesis of five mononuclear Fe(II) coordination compounds 1-5 containing perchlorate, tetrafluoroborate and triflate counterions. Single-crystal X-ray diffraction analysis confirmed the expected molecular structures of all the reported compounds, revealing a moderately distorted octahedral geometry of {FeN} coordination chromophores. All five compounds exhibit thermal spin crossover with temperatures allocated above 400 K.

Magnetic anisotropy and slow relaxation of magnetisation in double salts containing four- and six-coordinate cobalt(II) complex ions.

Four novel Co(II) coordination compounds 1-4 of the general formula [Co(L)][Co(NCY)]·CHCN (where L are tridentate ligands L1 = 2,6-bis(1-hexyl-1-benzimidazol-2-yl)pyridine for 1 and 2; L2 = 2,6-bis(1-octyl-1-benzimidazol-2-yl)pyridine for 3; L3 = 2,6-bis(1-dodecyl-1-benzimidazol-2-yl)pyridine for 4, Y = O for 1, 3, and 4 and Y = S for 2; = 0 for 1 and 3, = 0.5 for 2 and = 2 for 4) were prepared and characterised. The molecular structures of all four compounds consist of the hexacoordinate complex cation [Co(L)] and tetracoordinate complex anion [Co(NCY)], with distorted octahedral and tetrahedral symmetry of coordination polyhedra, respectively.

Comprehensive Exploration of Optics and Magnetism in a Hydrothermally Synthesized Nickel(II) Complex.

The hydrothermal reaction of 2-MeIm (2-MeIm: 2-methylimidazole) with nickel sulfate hexahydrate in methanol afforded a mononuclear complex formulated as [Ni(SO)(2-MeIm)(HO)]·CHOH (1). The title compound was described by X-ray single-crystal diffraction, thermal assessment, IR, and UV-vis spectroscopy. The crystal structure of is composed of segregated [Ni(SO)(2-MeIm)(HO)] neutral entities and a solvent methanol molecule.