New asymmetric cardanol-based porphyrins, free-base and coordinated with Ni, Co and Cu, were synthesized and completely characterized as A3B type. Such porphyrins were obtained aiming improved solubility in polar solvents due insertion of an −OH phenolic group. Their thermal and dielectric properties were also evaluated. Changes in the synthetic route reduced the reaction time and improved the yields of the aldehyde precursor obtainment. Electronic absorption spectra of the new porphyrins in CH 2 Cl 2 , EtOH and acetone, indicated a decrease in the ε (molar absorptivity) values with increasing solvent polarity, except for the nickel complex which, in acetone, showed a slight increase of 2% in the ε value. The dielectric measurements showed that the conductivity (σ) and the loss tangent (tan δ) increased with frequency, but the permittivity (ε') decreased. The results showed that the coordination of the porphyrin promoted a significant change in thermal and dielectric properties, specially for to the Ni-complex compound, which presented the best dielectric properties with interesting values of permittivity and loss tangent at 100 MHz (19.46 and 0.011 a.u., respectively). Keywords: asymmetric porphyrins, cardanol, dielectric properties IntroductionPorphyrins are relatively planar aromatic system consisting of four pyrrole type rings joined by four methynic carbons. They have attracted scientists from many areas due to their biological importance, their fascinating physical, chemical, and spectroscopic properties.1 These compounds have a high electron density due to its 18 π-electrons delocalized on the macrocyclic ring, which are responsible for their spectroscopic characteristics. 2Porphyrin and its derivatives play multiple roles in nature, such as energy transfer and light absorption in a wide range of the electromagnetic spectrum. Such features are of great interest to the industry of optoelectronic components, such as solar cells, due to its ability to act as photosensitizers when irradiated under visible light.3 Thus, this is certainly one of the most promising areas of application for these compounds. The structural modeling and synthesis of new porphyrins has grown exponentially in order to control their electronic and thermal properties. 4 The addition of substituents at the meso positions and metal ions in the center of porphyrins can improve the electrical and magnetic properties, protecting against auto-oxidation and reducing the formation of dimers. However, these structural modifications can promote, in some cases, a significant decrease in their planarity. 5A simple way to obtain porphyrins is the acid catalyzed condensation reaction of pyrrole with specific aldehyde, followed by oxidation of the porphyrinogen. This procedure, originally developed by Rothemund,6 has been refined by [7][8][9] due to the addition of metal salts to the reaction. Despite the modest yields, the relative simplicity of this method has become suited for preparation of large amounts of tetraarylporphyrins. Higher yields an...

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In this work we report the synthesis of new hybrid nanomaterials in the core/shell/shell morphology, consisting of a magnetite core (Fe3O4) and two consecutive layers of oleic acid (OA) and phthalocyanine molecules, the latter derived from cashew nut shell liquid (CNSL). The synthesis of Fe3O4 nanoparticle was performed via co-precipitation procedure, followed by the nanoparticle coating with OA by hydrothermal method. The phthalocyanines anchorage on the Fe3O4/OA core/shell nanomaterial was performed by facile and effective sonication method. The as obtained Fe3O4/OA/phthalocyanine hybrids were investigated by Fourier transform infrared spectroscopy, X-ray diffraction, UV-visible spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis and magnetic measurements. TEM showed round-shaped nanomaterials with sizes in the range of 12–15 nm. Nanomaterials presented saturation magnetization (Ms) in the 1–16 emu/g and superparamagnetic behavior. Furthermore, it was observed that the thermal stability of the samples was directly affected by the insertion of different transition metals in the ring cavity of the phthalocyanine molecule.

Aedes aegypti is the main vector of three neglected tropical diseases: dengue, zika and chikungunya. Dengue is under surveillance by health organizations worldwide due to the risk of epidemics. Since there is no specific treatment for dengue, most studies have focused on preventing the reproduction and/or development of the mosquitoes. We studied the larvicidal activity of five phosphates and phosphorothioates derived from cardol, one of the four main components of cashew nut shell liquid (Anacardium occidentale L.), at different concentrations. The organophosphorothioate derivatives were tested for their in vitro inhibitory potential against acetylcholinesterase (AChE). One compound, Cdl.i-dPS (median lethal concentration (LC 50) = 0.8 ppm), was four times more efficient compared to an important commercial larvicide, Temephos (LC 50 = 3.2 ppm), and showed greater AChE inhibition than its monosubstituted analogue and Temephos.