Publications by authors named "Maria Vasconcellos-Dias"

Three new complexes [Mo(η³-C₃H₅)Br(CO)₂{PrN=C(R)C₅H₄N}], where R = H (IMP = -isopropyl 2-iminomethylpyridine), Me, and Ph, were synthesized and characterized, and were fluxional in solution. The most interesting feature was the presence, in the crystal structure of the IMP derivative, of the two main isomers (allyl and carbonyls ), namely the equatorial isomer with the Br trans to the allyl and the equatorial with the Br trans to one carbonyl, the position trans to the allyl being occupied by the imine nitrogen atom. For the R = Me complex, the less common axial isomer was observed in the crystal.

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Several molybdenum complexes, [Mo(η(3)-C(3)H(5))X(CO)(2)(N-N)] (N-N = 1,10-phenanthroline, phen: X = CF(3)SO(3)T1, X = Br B1, X = Cl C1; N-N = 2,2'-bipyridyl, X = CF(3)SO(3)T2, X = Br B2) and [W(η(3)-C(3)H(5))Br(CO)(2)(phen)] (W1) have been synthesized and characterized. Their antitumor properties have been tested in vitro against human cancer cell lines cervical carcinoma (HeLa) and breast carcinoma (MCF-7) using a metabolic activity test (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT), leading to IC(50) values ranging from 3 to 45 μM, approximately. Most complexes exhibited significant antitumoral activity.

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Article Synopsis
  • Organic-inorganic mesoporous materials like MCM-41 can be synthesized through two main methods: post-synthesis derivatization and one-pot synthesis.
  • The study evaluated samples derived from Si-based MCM-41, focusing on their local characteristics through advanced spectroscopy techniques, including DRIFT and Raman spectroscopy.
  • Findings indicate that hydrophilicity and structural integrity of these materials depend on the type of organic groups used and the synthesis method, with pressure affecting the channel structure due to low mechanical stability.
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