Márcio P. de Araujo

Synthesis, characterization and cytotoxic activities of the [RuCl2(NO)(dppp)(L)]PF6 complexes

The synthesis and characterization of ruthenium compounds of the type [RuCl(2)(NO)(dppp)(L)]PF(6) [dppp=1,3-bis(diphenylphosphino)propane; L=pyridine, 4-methylpyridine, 4-phenylpyridine and dimethyl sulfoxide] are described. The complexes were characterized by elemental analysis, UV/Vis and infrared spectroscopy, cyclic voltammetry, and X-ray crystallography for the complexes with the pyridine and 4-methylpyridine ligands. In vitro evaluation of these nitrosyl complexes revealed cytotoxic activity from 7.1 to 19.0 microM against the MDA-MB-231 breast tumor cells and showed that, in this case, they are more active than the reference metallodrug cisplatin. The 1,3-bis(diphenylphosphino)propane and the N-heterocyclic ligands alone failed to show cytotoxic activities at the concentrations tested (maximum concentration utilized=200 microM).

Trichloro-bridged diruthenium (III, III) complexes: X-ray isomorphous structures of [Ph3X=O...H...O=XPh3][Ru2Cl7(XPh3)2].0.5(CH2Cl2)(H2O)(X = As or P)

The triply chloro-bridged binuclear complexes [Ph3X=O···H···O=XPh3][Ru2Cl7(XPh3)2]·0.5(CH2Cl2)(H2O) (X = As or P) were obtained from [RuCl3(XPh3)2DMA]·DMA (DMA = dimethylacetamide) CH2Cl2/Et2O solution. The structures were characterized by X-ray diffraction studies. The complexes are formed from two Ru atoms bridged by three chloride anions. The two ruthenium atoms are also coordinated to two non-bridging Cl atoms and an AsPh3 or PPh3 ligand respectively. As an interesting feature, the cations of these complexes are protons, trapped in a very short hydrogen bond between two triphenylarsine or triphenylphosphine oxide molecules.

Bis(diphenylphosphino)amines-containing ruthenium cymene complexes as potential anti- Mycobacterium tuberculosis agents

Several ruthenium complexes have been investigated regarding anti-Mycobacterium tuberculosis (anti-MTb) activity, with some diphosphine-containing ruthenium complexes comparable to first and second line drugs. However, to the best of our knowledge, there is no PNP-containing ruthenium complexes applied as metallodrugs. Thus, this study focused on the synthesis, characterization and anti-MTb activity of a new series of coordination compounds with general formula [RuCl(η6-p-cymene)(PNRP)]X (R=CH2Py (Py=pyridine)-[1a], CH2Ph (Ph=phenyl)-[1b], Ph-[1c] and p-tol (p-tol=p-tolyl)-[1d]; X=PF6- or BF4-). The complexes were fully characterized by NMR (1H, 31P{1H}), vibrational spectroscopy (FTIR), ESI-MS, molar conductance, elemental analysis and X-ray diffraction studies. The molecular structures of [1a]PF6, [1c]BF4 and [1d]PF6 were determined and confirm the spectroscopic and ESI-MS data. The complexes were used in anti-MTb trials, and the preliminary results are presented. The complexes are promising anti-MTb agents with MIC90 (Minimum Inhibitory Concentration of compounds required to inhibit the growth of 90% of MTb) values comparable with the Ethambutol, the reference drug used in this work, and complex [1a]BF4 presented the highest selectivity index.

p,t-[Ru(CO)(PR3)(tren)]2+ [R = Ph or p-tol; tren = tris(2-aminoethyl)amine], Ru(II) complexes bearing a simple tripodal tetradentate amine: synthesis, characterization, and antimicrobial activity

Abstract Complexes with general formula p,t-[Ru(CO)(PR3)(tren)]X2 [R = Ph (1) or p-tol (2); tren = tris(2-aminoethyl)amine; X = Cl− or ] were prepared from [RuCl2(CO)(dmf)(PR3)] by direct reaction with tren. The complexes were fully characterized by NMR (1H, 31P{1H}, HMBC 1H–31P), FTIR and ESI-MS spectroscopy, elemental analysis, and the structures of p,t-[Ru(CO)(PPh3)(tren)](PF6)2 (1•PF6) and p,t-[Ru(CO)(P{p-tol}3)(tren)]Cl2 (2•Cl) were determined by X-ray diffraction. The water soluble complexes 1•Cl and 2•Cl were tested as antimicrobial agents against Gram (+) and Gram (−) bacteria with the latter showing superior activity than the approved antimicrobial agent chloramphenicol in one of the strains.

Simulação Monte Carlo no ensino de luminescência e cinética de decaimento de estados excitados

A software based in the Monte Carlo method have been developed aiming the teaching of important cases of mechanisms found in luminescence and in excited states decay kinetics, including: multiple decays, consecutive decays and coupled systems decays. The Monte Carlo Method allows the student to easily simulate and visualize the luminescence mechanisms, focusing on the probabilities of the related steps. The software CINESTEX was written for FreeBASIC compiler; it assumes first-order kinetics and any number of excited states, where the pathways are allowed with probabilities assigned by the user.