Milton K. Morigaki

Salinidade em petróleo bruto: otimização de metodologia e proposta de um novo método para extração de sais em petróleo

The quantity of salts in the crude oils depends on the origin and of the wells production and these salts cause several problems during the transport and the process of refine as corrosions, incrustations and deactivation of the employed catalysts in the refineries. In this study were implemented changes for improvements in the execution of ASTM D 6470 method and has also developed a new methodology of extraction system of salts using process of mechanical agitation without heating. The results of the optimization produce larger efficiency and safety to the process compared to the traditional ASTM method.

Facile conversion of bis(alkynyl) into diyne ligand on platinum assisted by electrophilic gold phosphine

Abstract 31P NMR spectroscopy measurements were used to establish the course for the stoichiometric-dependent reactions between [Au(PPh3)]+ and [Pt(CCPh)2(dppf)] (1), which for equimolar amounts afford as the unique product [Pt-{η3-C(CCPh)C(Ph)Au(PPh3)}(dppf)]+ (2), but any excess of 1 gives also [Pt(η2-PhCCCCPh)(dppf)] (3) [dppf=1,1′-bis(diphenylphosphine)ferrocene]. Both compounds 2 and 3 were obtained straightforwardly by the reactions of 3 with [Au(PPh3)]+ and [Pt(C2H4)(dppf)] with 1,4-diphenylbutadiyne, respectively. The X-ray crystal structure analysis of 3 confirmed a trigonal-planar coordination geometry about the platinum atom, and a bent η2-coordinated diyne ligand.

Mössbauer parameters and structure correlations in five-coordinate iron complexes

Abstract Iron-57 Mossbauer spectroscopy data are reported for [Fe(Bu t NC) 5 ], [Fe(CO) 4 (Bu t NC)] and [(PPh 3 ) 2 N][Fe(CO) 4 (CN)] complexes in order to examine the bonding character and geometrical changes of several iron penta-coordinate complexes. The small quadrupole splitting value of 0.88 mm s −1 measured for the distorted trigonal bipyramidal [Fe(Bu t NC) 5 ] differs significantly from these found for regular geometries. As a consequence of this unusual result, a new correlation method of analysis was proposed for 13 known structures of five-coodinate [FeL 5 ], axially substituted [Fe(CO) 4 L′] and [{Fe(CO) 4 } n L″] n− complexes (L = CO or Bu t NC), on the basis of deviations from the idealized trigonal bipyramidal structure and changes in the quadrupole splittings. Furthermore, correlations involving Mossbauer data and IR carbonyl stretching frequencies were used to answer more detailed electronic and stereochemical questions.

Preparation and Mössbauer study of iron-mercury halide complexes containing isocyanide and carbonyl ligands

SummaryComplexes [Fe(t-BuNC)n(CO)5-n](n = 1 or 2) react with equimolar amounts of mercury(II) halides in acetone to form neutral iron-mercury adducts [Fe(t-BuNC) (CO)4−(HgX2)] and [Fe(t-BuNC)2(CO)3(HgX2)] (X = Cl or I), while [Fe(t-BuNC)5] reacts with solid mercury halides in petroleum ether to give the salts [Fe(t-BuNC)5(HgX)]-HgX3 (X = Br or I). Product assessment was based upon analytical and spectroscopic data, the Mössbauer effect and on molar conductivity studies.

Preparation and Mössbauer studies of iron-mercury mixed isocyanide-carbonyl complexes

The reactions of [Fe(t-BuNC)3(CO)2] with HgX2 (X= Cl, Br or I) give two different types of iron-mercury halide complex, depending on the molar ratio of reactants used. An equimolar ratio of the reactants produces the neutral adducts [Fe(t- BuNC)3(CO)2(HgX2)],whereas two equivalents of HgX2 generate the electrolytes [Fe(t- BuNC)3(CO)2(HgX)]HgX3. The Mössbauer, i.r. data, and conductivity measurements of these complexes are presented and discussed in terms of their chemical structures and bonding.

Synthesis and characterization of nanostructured iron compounds prepared from the decomposition of iron pentacarbonyl dispersed into carbon materials with varying porosities

This work describes the production and characterization of carbon-iron nanocomposites obtained from the decomposition of iron pentacarbonyl (Fe(CO)5) mixed with different carbon materials: a high surface area activated carbon (AC), powdered graphite (G), milled graphite (MG), and carbon black (CB). The nanocomposites were prepared either under argon or in ambient atmosphere, with a fixed ratio of Fe(CO)5 (4.0 mL) to carbon precursor (2.0 g). The images of scanning electron microscopy and the analysis of textural properties indicated the presence of nanostructured Fe compounds homogeneously dispersed into the different classes of pores of the carbon matrices. The elemental Fe content was always larger for samples prepared in ambient atmosphere, reaching values in the range of 20–32 wt%. On the other hand, samples prepared under argon showed reduced Fe content, with values in the range 5–10 wt% for samples prepared from precursors with low surface area (G, MG, and CB) and a much higher value (~19 wt%) for samples prepared from the precursor of high surface area (AC). Mössbauer spectroscopy and X-ray diffractometry showed that the nanoparticles were mostly composed of iron oxides in the case of the samples prepared in oxygen-rich ambient atmosphere and also for the AC-derived nanocomposite prepared under argon, which is consistent with the large oxygen content of this precursor. For the other precursors, with reduced or no oxygen content, metallic iron and iron carbides were found to be the dominant phases in samples prepared under oxygen-free atmosphere. The samples prepared in ambient atmosphere and the AC-derived sample prepared under argon exhibited superparamagnetic behavior at room temperature, as revealed by temperature-dependent magnetization curves and Mössbauer spectroscopy.

Novel neutral iron(II) isocyanide maleonitrile dithiolate [Fe(S2C2(CN)2)(t-BuNC) 4] compound

FeBr2 reacts with the S2C2(CN)22- ion (1:1 ratio) in the presence of an excess of t-BuNC in THF to give the mixed ligand [Fe(S2C2(CN)2)(t-BuNC) 4] compound. This neutral product with a formal oxidation state of two for the iron atom was characterized by conductivity measurements, and, i.r., Mossbauer, 13C and 1H n.m.r. spectroscopy. There is a Fe-C p back-donation strengthened towards isocyanide ligands, according to the data of 13C, 1H n.m.r. and Mossbauer spectroscopy.

A síntese do aduto binuclear [Fe(CNBu t)(CO)4(HgSO4 )]

The binuclear [Fe(CNBut)(CO)4(HgSO4 )] adduct was obtained in the reaction of HgSO4 with [Fe(CNBut)(CO)4] in methanol. This adduct, without a similar in the homoleptic pentacarbonyliron, was characterized by analytical and spectroscopic data. Further Mossbauer and molar conductivity studies have confirmed its adduct nature.