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.

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.

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.

Os complexos polinucleares [{PdCl2(µ-Htrz)}n] (1) e [{PdBr2(µ-Htrz)}n] (2) (Htrz = 1,2,4-triazol) foram sintetizados neste trabalho. O composto 1 foi preparado a partir da substituição da acetonitrila do precursor [PdCl2(MeCN)2] pelo 1,2,4-triazol. A adição posterior de brometo de potássio ao meio reacional resultou na formação do complexo 2. Os complexos inéditos foram isolados, purificados e caracterizados por análise elementar, espectroscopias vibracional no infravermelho e eletrônica no UV-visível e curvas de análise termogravimétrica (TG). Os resultados experimentais sugerem que, em ambos os casos, a coordenação do 1,2,4-Htrz ocorra via átomos N(2) e N(4), atuando como pontes entre centros de paládio. O poliedro de coordenação quadrado-planar ao redor do paládio(II) é determinado pelos dois átomos de N do heterociclo e por dois ligantes cloro (1) ou bromo (2), em uma provável configuração trans. As curvas TG indicaram que a natureza do ligante aniônico não afeta significativamente a estabilidade térmica de 1 e 2. Os produtos finais de decomposição térmica foram identificados como paládio metálico pela técnica de difratometria de raios X de pó. Testes preliminares envolvendo a avaliação dos efeitos dos compostos 1, 2 e Htrz na produção de H2O2 e NO em culturas de macrófagos peritoneais de camundongos BALB/c foram realizados in vitro.

The 1,2,4-triazolyl-bridged polynuclear complexes [{PdCl2(µ-Htrz)}n] (1) and [{PdBr2(µ-Htrz)}n] (2) have been obtained in this work. Compound 1 is prepared by the displacement of acetonitrile from [PdCl2(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 H2O2 and NO production in cultures of peritoneal macrophages from BALB/c mice were carried out in vitro.