Studies have been made of photochemical and thermal reaction sequences through which bisubstituted acetylenes are transformed in (CsHS>Co-carbonyl reaction systems into cyclobutadiene and cyclopentadienone complexes and hexasubstituted benzenes. A primary intennediate observed by its IR spectrum in low-temperature photochemical reactions of (CsHs)Co(COh with diphenyl alkynes RC=CR is the mixed ...

The essential involvement of manganese in photosynthetic water oxidation was implicit in the observation by Pirson in 1937 that plants and algae deprived of Mn in their growth medium lost the ability to evolve O2. Addition of this essential element to the growth medium resulted in the restoration of water oxidation within 30 min. There is increased interest in the study of Mn in biological chem...

The photo-induced decarbonylation o f Cp*Cr(CO)2NO in acetonitrile solution in the presence o f excess sulfur leads to the cjWo-pentasulfido complex Cp*Cr(NO)(S5) (1 a), while in the case o f limited sulfur supply the binuclear bis(//-disulfido) complex Cp*2Cr2(NO)2(/i-S2)2 (4 a) is formed preferentially. The corresponding reaction with elemental selenium produces Cp*2Cr2(N O )2(//-Se2)2 (4b), ...

Complex IV in the respiratory chain of mitochondria and bacteria catalyzes reduction of molecular oxygen to water, and conserves much of the liberated free energy as an electrochemical proton gradient, which is used for the synthesis of ATP. Photochemical electron injection experiments have shown that reduction of the ferric/cupric state of the enzyme's binuclear heme a3/CuB center is coupled t...

In the present study, the division modalities and regularity of rat cardiomyocytes from different developing stages were investigated with immunohistochemistry, transmission electron microscopy and cell culture in vitro. The results showed that the cells with mitotic figure and binuclear cells exist in the normal cardiomyocytes in prenatal and postnatal life. There are two types of binuclear ca...

A dominant feature of the inorganic chemistry of manganese is the variety of complexes that can be made with different oxidation levels ( + 11+ IV) of the manganese, and living systems have utilized this property in that manganese-containing en­ zymes are involved in many diverse redox func­ tions [1]. The biological function that has generat­ ed most interest is the photosynthetic oxygen evolv...

The reaction of [Ag(MeCN)(4)]ClO(4) with N,N,N',N'-tetra(diphenylphosphanylmethyl)ethylenediamine (dppeda) in CH(2)Cl(2)/MeOH afforded an unexpected cationic binuclear complex [Ag(2)(L(1))(2)(η,η-μ-ClO(4))(2)](ClO(4))(2) (L(1) = N,N'-bis(diphenylphosphanylmethyl)-3H-4,5-dihydroimidazole-1-ium) (1). Compound 1 was also prepared in high yield from reactions of [Ag(MeCN)(4)]ClO(4) with N,N'-bis(di...