A new type of anion receptor: pyrrolyl quinones

Artículo científicoThe synthesis of a novel 2-dipyrrolyl-2,5-dimethyl-p-benzoquinone is described, and its interactions with fluoride were characterized. An unprecedented interaction between fluoride anions and the quinone ring was observed

Crystal structure of N-[(E)-(1,3-benzodioxol-5-yl)methylidene]-4-chloroaniline

In the title compound, C14H10ClNO2, obtained by the condensation of 4-chloroaniline and piperonal, the five-membered ring is almost planar (r.m.s. deviation = 0.023 Å) and the dihedral angle between the aromatic rings is 43.22 (14)°. In the crystal, a short O...Cl contact of 3.173 (2) Å is observed. The molecules are arranged into corrugated (010) layers

Molecular Dynamics Analysis of PVA- AgnP

The molecular dynamics of PVA/AgnP composites were studied by dielectric spectroscopy (DS) in the 20–300°C temperature range. Improper water elimination leads to misinterpretation of thermal relaxations in PVA composites in agreement with the previous report for pristine PVA. The evaporation of water and its plasticizing effect are more evident in pure PVA confirming the existence of strong interaction between OH groups of PVA chains and AgnP. Dry films show a single nonlinear VFT dependence (from 45°C until melting) associated to the α-relaxation and, therefore, to the glass transition phenomenon and from dielectric measurements, the Tg of composites vary from 88°C for pristine PVA to 125°C for PVA/AgnP (5 wt%). Below 45°C, dry films exhibit a single Arrhenius behavior showing a 3D hopping conductivity as explained based on the variable range hopping model. PVA/AgnP composites have higher conductivity compared to pristine PVA, and it increases as AgnP weight percent increases. Finally, DMA measurements support the statement that a secondary relaxation was erroneously assigned as the glass transition of PVA and composites in previous reports