Inhibitive properties and surface morphology of a group of heterocyclic diazoles as inhibitors for acidic iron corrosion.

The heterocyclic diazoles 3-amino-1H-isoindole, indazole, imidazole, 4-bromoimidazole, 4-methylimidazole, pyrazole, 4-nitropyrazole, and 4-sulfopyrazole were investigated as corrosion inhibitors of iron in 1 M HCl using ac and dc techniques. The polarization curves showed a decrease in corrosion current for the inhibitor-containing solution. Impedance spectra demonstrate that the charge-transfer resistance in the presence of these inhibitors was greater than in inhibitor-free solution, except for 4-nitropyrazole. The resistance increased with inhibitor concentration and with immersion time. The structural and electronic parameters of these diazoles were calculated using computational methodologies. The elemental composition and the speciation of the treated surfaces were investigated via XPS measurements, and morphological changes were monitored by vertical scanning interferometery.

Biological activity of some cobalt(II) and molybdenum(VI) complexes: in vitro cytotoxicity.

Cytotoxicity and cell growth inhibition studies were performed for five distinct cobalt(ll) [Co(2)(acac)tpmc](ClO(4))(3), [Co(2)(dibzac)tpmc](ClO(4))(3), [Co(2)(hfac)tpmc](CIO(4))(2), [Co(2)(tmhd)tpmc](CIO(4))(3) and [Co(2)(ox)tpmc](CIO(4))(2).3H(2)0 and five molybdenum(Vl) complexes, [MoO(2)(pipdtc)(2)], [MoO(2)(morphdtc)], [MoO(2)(timdtc)(2)], [MoO(2)(pzdtc)(2)] and [MoO(2)(N-Mepzdtc)(2)]. The former were tested in two leukemia cell lines: chronic myelogenic leukemia (K562) and human promyelocytic cell line (U937). They showed to have relatively high toxicity in K562 cells and a relatively low cytotoxicity in U937 cells, as assessed by both MTT and Trypan Blue assays. The five molybdenum complexes were tested in human promyelotic U937 cell line and they showed to have high toxicity.