Synthesis, isolation, and structural characterization of the C4h isomer of metal(1,2-naphthalocyanine) and its one-dimensional conductor of the axially substituted species

The C4h isomer of the 1,2-Nc (1,2-naphthalocyaninato) ligand has been efficiently isolated as a hydrated magnesium complex by the fractional crystallization from the benzene/acetone solution after treating the crude mixture of the four isomers (C4h, C(s), C2v, D2h) with benzene. The C4h symmetry has been confirmed by X-ray structure analysis. The central metal ion has been demetalated and subsequently converted to the Li2 complex followed by conversion to the cobalt(II) complex. Electrochemical oxidation of the Co(III)(1,2-Nc)(CN)2 anion prepared from the cobalt(II) complex with TPP (tetraphenylphosphonium) has yielded a partially oxidized salt, TPP[Co(III)(1,2-Nc-C4h(CN)2]2. The crystal comprises slipped stacked Co(III)(1,2-Nc-C4h)(CN)2 one-dimensional chains and one-dimensional arrays of TPPs. The conductivity at room temperature is 0.1 S cm(-1), and the temperature dependence is semiconducting with a small activation energy of about 0.05 eV. The positive temperature-independent value of about 60 microV deg(-1) observed in the thermoelectric power measurements suggests that the salt is in the correlated hopping regime.     

Substrate specificity analysis of protein kinase complex Dbf2-Mob1 by peptide library and proteome array screening

Background  

The mitotic exit network (MEN) is a group of proteins that form a signaling cascade that is essential for cells to exit mitosis in Saccharomyces cerevisiae. The MEN has also been implicated in playing a role in cytokinesis. Two components of this signaling pathway are the protein kinase Dbf2 and its binding partner essential for its kinase activity, Mob1. The components of MEN that act upstream of Dbf2-Mob1 have been characterized, but physiological substrates for Dbf2-Mob1 have yet to be identified.     

Steady streaming around a spherical drop displaced from the velocity antinode in an acoustic levitation field

The steady (acoustic) streaming associated with a sphericaldrop displaced from the velocity antinode of a standing waveis studied. The ratio of the particle size to the acoustic wavelengthis treated as small but non-zero, and the solution is developedin the form of a two-term expansion in terms of the correspondingsmallness parameter. The drop viscosity is assumed to be muchhigher than that of the surrounding fluid, which is the casefor a drop in a gas medium. There are essentially three distinctregions where the steady streaming flow is analysed: insidethe drop (internal circulation), in the Stokes shear-wave layerat the surface on the gas side, and the gas outside the Stokeslayer (the outer streaming region). Solutions for the internalcirculation and the outer streaming are obtained in the limitof small Reynolds number. Despite the gas-to-liquid viscosity ratio being small, the outerstreaming may be dramatically affected by the fact that thesphere is liquid as opposed to solid. The parameter that measuresthe effect of liquidity is essentially the viscosity ratio dividedby the relative (to the particle size) thickness of the Stokeslayer. The case of a solid sphere is recovered by letting thisparameter go to zero.     

Synthesis, structure, and catalytic activity of mononuclear iron and (mu-Oxo)diiron complexes with the ligand 2,6-bis(N-methylbenzimidazol-2-yl)pyridine

Iron complexes including polyimidazole and exchangeable ligands are studied with the aim of modeling the structural and functional features of the non-heme iron centers of dinuclear proteins, such as methane monooxygenase. In [Fe(2)OL(2)(MeOH)(2)(NO(3))(2)](NO(3))(2) (1) (L = 2,6-bis(N-methylbenzimidazol-2-yl)pyridine), each Fe(III) is in a distorted octahedral environment and has a donor set of N(3)O(3) which includes three N atoms from L and three O atoms from a nitrate, micro-oxo, and methanol. In complex [FeLCl(3)] (2) (L = 2,6-bis(N-methylbenzimidazol-2-yl)pyridine), Fe(III) is coordinated to three nitrogen atoms from L and three chloride ions. Complex 1 efficiently catalyzed the oxidation of cyclohexane with 51% conversion to cyclohexanol. It also catalyzed the epoxidation of styrene, cyclohexane, 2-methyl-2-butene, and cis- and trans-2-heptene with 51-84% conversions and high selectivity (71-99%) for epoxide products. Complex 2, however, has no specific reactivity toward these substrates. From the alcohol/ketone (A/K) ratio close to 1 in the oxidation of cyclohexane, the low KIE (kinetic isotope effect K(H)/K(D) ratio = 1.8) for cyclohexanol formation, and the nonstereospecificity of the oxidation of cis-dimethylcyclohexane, it can be concluded that long-lived alkyl radicals are involved in the oxidation catalyzed by complex 1. On the other hand, the stereospecific epoxidation of alkenes, the stereoselective oxidation of cumene, and the high degree of retention of configuration in the oxidation of cis- and trans-2-heptene suggest that a nonradical species, probably a metal-based intermediate, is involved in the oxidation of alkenes and cumene.     

Ueber die Bestimmung des Cadmiums

Ohne Zusammenfassung