A new protocol for the catalytic synthesis of cyclopropanes using electron-deficient alkenes is presented, which is catalysed by a series of affordable, easy to synthesise and highly active substituted cobalt(II) tetraaza[14]annulenes. These catalysts are compatible with the use of sodium tosylhydrazone salts as precursors to diazo compounds in one-pot catalytic transformations to afford the de...

Understanding the activity and selectivity of molecular catalysts for CO2 reduction to fuels is an important scientific endeavour in addressing the growing global energy demand. Cobalt–terpyridine compounds have been shown to be catalysts for CO2 reduction to CO while simultaneously producing H2 from the requisite proton source. To investigate the parameters governing the competition for H redu...

Inorganic cobalt was found to induce heme oxygenase activity in primary cultures of embryonic chick liver cells and to inhibit the induction of delta-aminolevulinate synthetase by the porphyrinogenic compounds allylisopropylacetamide, dicarbethoxy-1,4-dihydrocollidine, etiocholanolone, phenobarbital, Aroclor (R)1254, and secobarbital. Much smaller concentrations of Co2+ (5 muM) were required to...

Even though compounds of nickel, arsenic, cobalt and cadmium are carcinogenic, their mutagenic potentials are rather weak. In contrast, they exert pronounced comutagenic effects, which may be explained by disturbances of different DNA repair systems. Thus, cobalt, arsenic, nickel and cadmium interfere with base and nucleotide excision repair, even though they affect different steps of the respe...

The preparation and characterization of two mononuclear cobalt(III) tropocoronand complexes, [Co(TC-5,5)](BF4) and [Co(TC-6,6)](BPh4), are reported. The cobalt(III) centers exist in rare pseudotetrahedral conformations, with twist angles of 65° and 74° for the [Co(TC-5,5](+) and [Co(TC-6,6)](+) species, respectively. Structural and electrochemical characteristics are compared with those of newl...

Reaction of [Co(TC-n,m)]+ with (Me4N)(SC6F5), where (TC-n,m) is a tropocoronand with n and m linker chain methylene groups, yielded the thiolate complexes [Co(SC6F5)(TC-3,3)] (1a), and [Co(SC6F5)(TC-4,4)] (2a), which were structurally characterized. Use of more electron-releasing thiolates afforded the [Co(TC-n,m)] reduction product and the corresponding disulfide. The bent nitrosyl complexes [...

Understanding the activity and selectivity of molecular catalysts for CO2 reduction to fuels is an important scientific endeavour in addressing the growing global energy demand. Cobalt-terpyridine compounds have been shown to be catalysts for CO2 reduction to CO while simultaneously producing H2 from the requisite proton source. To investigate the parameters governing the competition for H+ red...

Samples of CoP3, CoAs3 and CoP1.5As1.5 have been synthesized and their thermoelectric properties measured. All three samples show semiconducting behavior. The Seebeck coefficients of CoP3 and CoAs3 are weakly dependent on temperature and are relatively small with maximum values of about 40 and 50 μV/K, respectively. The Seebeck coefficient of the solid solution gradually decreases with increasi...