DMSO Molecule as Ancillary Ligand in Ru-Based Catalysts for Ring Opening Metathesis Polymerization

A polimerização via metátese por abertura de anel (ROMP) de norborneno (NBE) ocorre em presença do complexo fac-[RuCl 2 (S-DMSO) 3 (O-DMSO)] e etildiazoacetato (5 µL), onde DMSO é dimetilsulfóxido coordenado pelo átomo de enxofre ou de oxigênio. O rendimento é 62% (PDI = 1,64) à temperatura ambiente por 5 min e 88% (PDI = 1,93) a 50 ºC por 30 min, com [NBE]/ [Ru] = 516 em CHCl 3 . Na presença de NBu 4 ClO 4 o rendimento é 90% (PDI = 1,64) à temperatura ambiente por 5 min. O complexo é praticamente inativo quando uma ou duas moléculas de DMSO são substituídas por piridina, imidazol, 2-metil-imidazol ou benzoimidazol. A formação in situ da espécie catalítica e os comportamentos das moléculas de DMSO como ligantes ancilares nas reatividades dos complexos de Ru II são discutidas nesse trabalho. The ring-opening metathesis polymerization (ROMP) of norbornene (NBE) occurs in the presence of the fac-[RuC

Romp as a versatile method for the obtention of differentiated polymeric materials

Ring Opening Metathesis Polymerization (ROMP) of cyclic olefins is a powerful transition metal-catalyzed reaction for syntheses of polymers and copolymers. The key feature of this reaction is the [2+2]-cycloaddition mechanism, with retention of the olefinic unsaturation in the polymer chain and occurrence of living polymerization. With the development of metal-carbene type catalysts for this process, many addressed polymeric materials have been successfully prepared to be employed in several fields of the science and technology. This review summarizes recent examples of syntheses of polymers with amphiphilic features such as block, graft, brush or star copolymers; as well syntheses of biomaterials, dendronized architectures, photoactive polymers, cross-linked or self-healing materials, and polymers from renewed supplies

Analysis of evolution of Parecis Basin through potential methods.

A intracrat?nica Bacia dos Parecis est? localizada na regi?o centro-oeste do Brasil, no setor sudoeste do Cr?ton Amaz?nico, recobrindo partes das prov?ncias Suns?s, Rond?nia-Juruena e Tapaj?s-Parima (Santos 2002). Ap?s os trabalhos de Teixeira (1993) e Siqueira (1989), embasados em dados geof?sicos e geol?gicos, a bacia foi dividida, de oeste para leste, em tr?s dom?nios tectono-sedimentares: o extremo oeste, uma depress?o tect?nica ( Fossa Tect?nica de Rond?nia); a por??o central, um baixo gravim?trico e o extremo leste, uma bacia interior denominada por Schobbenhaus (1984) de Bacia do Alto Xing?. Durante o Ordoviciano at? o Eo-Permiano, a regi?o Amaz?nica foi afetada por um evento extensional, quando foram depositados os sedimentos ordovicianos da Forma??o Cacoal, representando o registro do est?gio rifte da Bacia dos Parecis. Do Devoniano ao Eo-Permiano as forma??es Furnas, Ponta Grossa, Pimenta Bueno e Fazenda da Casa Branca foram depositadas durante o est?gio sag da bacia. Durante o Mesoz?ico (Tri?ssico ao Cret?ceo) uma sucess?o de rochas vulc?nicas e sedimentares representa outro evento extensional . Este evento est? representado na Bacia dos Parecis pelos arenitos e?licos da Forma??o Rio ?vila e os derrames bas?lticos das forma??es Anar? e Tapirapu?. O Grupo Parecis, composto de conglomerados e arenitos, representa o est?gio deposicional relacionado ao Cret?ceo. Os dados gravim?tricos e magn?ticos da Bacia dos Parecis foram adquiridos pelo IBGE, PETROBRAS e CPRM. O mapa gravim?trico da Bacia dos Parecis obtido atrav?s do software O?sis/Geosoft mostra uma extensa anomalia Bouguer negativa que se destaca no interior do Cr?ton Amaz?nico, com desvio do campo regional da ordem de ?40 mgl. O trend estrutural regional de dire??o leste-oeste, com desvio do campo regional da ordem de 80 mgal, evidencia o prosseguimento dos grabens de Pimenta Bueno e Colorado, os quais comp?em a Fossa Tect?nica de Rond?nia, por baixo da seq??ncia mesoz?ica. A exist?ncia dessa estrutura ? sustentada pelo mapa da Deconvolu??o de Euler, obtido atrav?s de um processo de invers?o, a qual segue uma estimativa da profundidade da anomalia relacionada ao embasamento cristalino.The Parecis basin is located in central-western Brazil, on the southwestern part of the Amazon Craton, partially covering the Suns?s, Rond?nia-Juruena and Tapaj?s-Parima provinces (Santos 2002). Based on Teixeira (1993) and Siqueira (1989), the Parecis basin was divided, from west to east, into three tectono-sedimentary domains: the Rond?nia tectonic, the central compartment ( negative gravimetric anomaly) and a interior sag (Alto Xingu basin). During the Ordovician to Early Permian, the eastern Amazon region was affected by an extensional event and the Cacoal formation was deposited (rift stage of the Parecis basin). From Devonian to Early Permian, Furnas, Ponta Grossa, Pimenta Bueno and Fazenda da Casa Branca formations were deposited during the sag stage of the basin. Mesozoic (Late Triassic to Cretaceous) volcanic and sedimentary successions record another extensional event in the Amazon region. This event is represented in the Parecis basin by the eolian sandstones of the Rio ?vila Formation and the basalts of the Anar? and Tapirapu? formations. The Cretaceous depositional stage is represented by the Parecis Group. Gravity and magnetic data of the Parecis basin have been acquired by IBGE, PETROBRAS and CPRM. Gravimetry and magnetometry maps obtained through the use of the Oasis/Geosoft software show an extensive negative anomaly in the interior of the Amazon Craton, with an average deviation from regional field of -40 mgal. The east-west regional structural trend with a deviation from regional field of -80 mgal evidences the eastward continuity of Pimenta Bueno and Colorado grabens underneath the Mesozoic succession (Rond?nia tectonic low). The existence of this structure is supported by the Euler Deconvolution map, obtained through an inversion procedure that allowed an estimation of the anomaly (basement) depth

Organic additive-copper(II) complexes as plating precursors

Cu(II) ions previously coordinated with typical electroplating organic additives were investigated as an alternative source of metal for plating bath. The coordination complexes were isolated from reaction between CuSO(4) and organic additives as ligands (oxalate ion, ethylenediamine or imidazole). Deposits over 1010 steel were successfully obtained from electroplated baths using the complexes without any addition of free additives, at pH = 4.5 (H(2)SO(4)/Na(2)SO(4)). These deposits showed better morphologies than deposits obtained from CuSO(4) solution either in the absence or presence of oxalate ion as additive (40 mmol L(-1)), at pH = 4.5 (H(2)SO(4)/Na(2)SO(4))It is suggestive that the starting metal plating coordinated with additives influences the electrode position processes, providing deposits with corrosion potentials shifted over + 200 mV in 0.5 mol L(-1) NaCl (1 mV s(-1)). The resistance against corrosion is sensitive to the type of additive-complex used as precursor. The complex with ethylenediamine presented the best deposit results with the lowest pitting potential (-0.27 V vs 3.0 mol L(-1) CE). It was concluded that the addition of free additives to the electrodeposition baths is not necessary when working with previously coordinated additives. Thus, the complexes generated in ex-situ are good alternatives as plating precursors for electrodeposition bath. (C) 2009 Elsevier B.V. All rights reserved.CAPESCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNP

DMSO molecule as ancillary ligand in Ru-based catalysts for ring opening metathesis polymerization

The ring-opening metathesis polymerization (ROMP) of norbornene (NBE) occurs in the presence of the fac-[RuCl2(S-DMSO)3(O-DMSO)] complex and ethyldiazoacetate (5 μL), where DMSO is S- or O-bonded dimethylsulfoxide. The yield is 62% (PDI = 1.64) at room temperature for 5 min and 88% (PDI = 1.93) at 50 ºC for 30 min, with [NBE]/[Ru] = 516 in CHCl3. The yield is 90% (PDI = 1.64) in the presence of NBu4ClO4 at room temperature for 5 min. The complex is practically inactive when one or two molecules of DMSO are replaced by pyridine, imidazole, 2-methyl-imidazole or benzimidazole. The in situ formation of the catalytic species and the behavior of the DMSO molecules as ancillary ligands in the reactivity of the RuII complexes are discussed