Immunomodulatory effects of palladium(II) complexes of 1,2,4-triazole on murine peritoneal macrophages

The 1,2,4-triazolyl-bridged polynuclear complexes [{PdCl(2)(mu-Htrz)}(n)] (1) and [{PdBr(2)(mu-Htrz)}(n)] (2) have been obtained in this work. Compound 1 is prepared by the displacement of acetonitrile from [PdCl(2)(MeCN)(2)] by 1,2,4-triazole (Htrz). Further addition of potassium bromide to the reaction medium afforded complex 2. The new complexes have been isolated, purified and characterized by means of elemental analysis, IR and UV-visible electronic spectroscopies and thermogravimetric (TG) curves. The experimental data suggested that, in both cases, the coordination of 1,2,4-Htrz takes place through the N(2) and N(4) atoms, bridging the palladium centers. The square-planar coordination polyhedron of palladium(II) is determined by two nitrogen atoms from the triazole ligands, while the other two coordination positions are occupied by the chloro (1) or bromo (2) ligands. TG curves indicated that the nature of the anionic ligand does not affect significantly the thermal stability of 1 and 2. The final products of the thermal decompositions were identified as metallic palladium by X-ray powder diffractometry. Preliminary tests involving the evaluation of the effects of compounds 1, 2 and Htrz on H(2)O(2) and NO production in cultures of peritoneal macrophages from BALB/c mice were carried out in vitro

Spectroscopic characterization of schiff base-copper complexes immobilized in smectite clays

Herein, the immobilization of some Schiff base-copper(II) complexes in smectite clays is described as a strategy for the heterogenization of homogeneous catalysts. The obtained materials were characterized by spectroscopic techniques, mostly UV/Vis, EPR, XANES and luminescence spectroscopy. SWy-2 and synthetic Laponite clays were used for the immobilization of two different complexes that have previously shown catalytic activity in the dismutation of superoxide radicals, and disproportionation of hydrogen peroxide. The obtained results indicated the occurrence of an intriguing intramolecular redox process involving copper and the imine ligand at the surface of the clays. These studies are supported by computational calculations

COMO OBTER NANOPARTÍCULAS DE OURO USANDO SUCO DE LIMÃO?

This article refers about a green method for the preparation of gold nanoparticles using juice from four types of lemon (Tahiti, Key lime, Sicilian and Rangpur). The approach is based on a classic synthesis of nanoparticles using sodium citrate as reducing agent, since all these lemon varieties have citric acid in their compositions. Several characterization techniques demonstrated the efficacy of the method for obtaining red colloidal solutions (nanoparticles in the order of 5-25 nm). The importance of this attempt to make environmentally friendly synthesis of gold nanoparticles is linked to the several applications of these nanomaterials, the most important being biomedicine, catalysis, electronics, biochemical sensing and imaging

Thermal study of nickel(II) pyrazolyl complexes

The thermal behavior of the pyrazolyl complexes [NiCl2(HPz) 4] (1), [Ni(NCS)2(HPz)4] (2), [NiCl 2(HdmPz)4]·2H2O (3) and [Ni(NCS) 2(HdmPz)4]·2H2O (4) (HPz=pyrazole, HdmPz=3,5-dimethylpyrazole) has been studied by thermogravimetry (TG) and differential thermal analysis (DTA). The TG data indicated that the thermal stability of [NiX2(HL)4] (X=Cl, NCS) compounds varies depending on the pyrazolyl ligand in the following order HL=HPz>HdmPz. From the thermal decomposition of 3 and 4 it was possible to isolate the intermediate compounds [Ni(μ-Cl)2(HdmPz)2] (3a) and [Ni(μ-1,3-NCS) 2(HdmPz)2] (4a), respectively. The final products of the thermal decompositions of 1-4 were identified as NiO by X-ray powder diffraction. © 2005 Akadémiai Kiadó, Budapest

Thermal studies on nickel(II) 4-iodopyrazole complexes

This work describes the synthesis, IR and UV-Vis spectroscopic characterization as well the thermal behavior of the [NiCl2(HIPz)(4)]center dot C3H6O (1), [Ni(H2O)(2)(HIPz)(4)](NO3)(2) (2), [Ni(NCS)(2)(HIPz)(4)] (3) and [Ni(N-3)(2)(HIPz)(4)] (4) (HIPz = 4-iodopyrazole) pyrazolyl complexes. TG experiments reveal that the compounds 1-4 undergo thermal decomposition in three or four mass loss steps yielding NiO as final residue, which was identified by X-ray powder diffraction

HOW TO OBTAIN GOLD NANOPARTICLES FROM LEMON JUICE?

<p></p><p>This article refers about a green method for the preparation of gold nanoparticles using juice from four types of lemon (Tahiti, Key lime, Sicilian and Rangpur). The approach is based on a classic synthesis of nanoparticles using sodium citrate as reducing agent, since all these lemon varieties have citric acid in their compositions. Several characterization techniques demonstrated the efficacy of the method for obtaining red colloidal solutions (nanoparticles in the order of 5-25 nm). The importance of this attempt to make environmentally friendly synthesis of gold nanoparticles is linked to the several applications of these nanomaterials, the most important being biomedicine, catalysis, electronics, biochemical sensing and imaging.</p><p></p

Self-assembly of cyclometallated Pd(II) compounds directed by C-H center dot center dot center dot pi interactions: A structural evidence for metalloaromaticity in a cyclopalladated ring

Structural studies on the two binuclear cyclometallated compounds [Pd(C-2,N-bzan)(mu-N-3)](2) (1) and [Pd(C-2,N-bzan)(mu-Pz)](2) (2) (bzan = N-benzylideneaniline) have been carried out in this work. In both compounds, C-H center dot center dot center dot pi interactions play an important role in the molecular self-assembly. In complex 1, ortho-CH bonds from bzan moiety interact with the cyclopalladated ring at a distance of C-bzan center dot center dot center dot C-g 3.448(6) angstrom, providing a new structural evidence for the metalloaromaticity of the cyclometallated ring. (C) 2010 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

MOFs (METAL-ORGANIC FRAMEWORKS): UMA FASCINANTE CLASSE DE MATERIAIS INORGÂNICOS POROSOS

Metal-Organic Frameworks (MOFs) are, according to IUPAC, coordination polymers with an open framework containing potential voids, which can be accessible after activation processes. These materials have aroused interest in the academic environment – and more recently in industry - because their properties such as high crystallinity, permanent microporosity, high surface areas, and the possibility of functionalization. This has enabled applications in different areas, such as gas adsorption, catalysis, drug delivery, photonics and others. Depending on the judicious choice of the metals and the organic linkers, MOFs with different topologies and functions can be created. Synthetic routes for the preparation of these materials will be discussed, highlighting those in consonance with the Green Inorganic Chemistry. Strategies for controlling the size and morphology of the crystals will also be presented, as well the most recent methodologies for the large-scale production. This review will also discuss the use of MOFs in the context of energy and environment, particularly referring to the adsorption and/or transformation of CO2, storage of H2 and CH4 as well potable water capture

Supramolecular assemblies and magnetic behaviors of the M(II)/p-aminopyridine/malonate (M = Ni, Mn, Cu, Co) systems

The coordination compounds [Ni(mu-mal)(apy)(2)(H2O)]center dot 2.8H(2)O (1), [Mn(mu-mal)(H2O)(2)] (2), (apyH)(2)[Cu(mu-mal)(2)] (3) and (apyH)(2)[Co(mal)(2)(H2O)(2)] (4) (mal = malonate, apy = p-aminopyridine) have been synthesized and characterized by elemental analysis, vibrational spectroscopy, single crystal X-ray diffraction and magnetometry. With exception of 4, the malonate group acts as bridging ligand leading to the formation of one-dimensional polymeric chains. In compound 1 it was observed the coordination of the p-aminopyridine in the axial positions of the distorted octahedral coordination sphere. The solid-state structure exhibits a high complex 3D network formed by several supramolecular interactions. Magnetic properties were determined for all members of the series and indicate that the materials behave are normal paramagnets, except the Mn polymer 2 which exhibits an antiferromagnetic ground state. (C) 2013 Elsevier Ltd. All rights reserved