RESUMEN
We synthesised and characterised the racemic and chiral versions of two Zn salan fluorine-based complexes from commercially available materials. The complexes are susceptible to absorbing H2O from the atmosphere. In solution (DMSO-H2O) and at the millimolar level, experimental and theoretical studies identify that these complexes exist in a dimeric-monomeric equilibrium. We also investigated their ability to sense amines via19F NMR. In CDCl3 or d6-DMSO, strongly coordinating molecules (H2O or DMSO) are the limiting factor in using these easy-to-make complexes as chemosensory platforms since their exchange with analytes requires an extreme excess of the latter.
RESUMEN
Two propeller-shaped chiral CoIII3YIII complexes built from fluorinated ligands are synthesized and characterized by single-crystal X-ray diffraction (SXRD), IR, UV-vis, circular dichroism (CD), elemental analysis, thermogravimetric analysis (TGA), electron spray ionization mass spectroscopy (ESI-MS), and NMR (1H, 13C, and 19F). This work explores the sensing and discrimination abilities of these complexes, thus providing an innovative sensing method using a 19F NMR chemosensory system and opening new directions in 3d/4f chemistry. Control experiments and theoretical studies shed light on the sensing mechanism, while the scope and limitations of this method are discussed and presented.
RESUMEN
We describe a copper-mediated method that enables the synthesis of seven-membered-ring fused pyrroles (7-mrFPs). The protocol proceeds via an in situ spiro-intermediate ring expansion and tolerates a library of 7-mrFP derivatives with a broad range of functional groups in a simple step with tangible parameters and substrate adaptations. These rare 7-mrFPs are now accessible on a millimolar scale, and selected examples exhibit high antioxidant activity.
RESUMEN
A green anticorrosive composite (GA-AgNPs) has been formulated for steel in 15% HCl and 15% H2SO4 media. Characterization of GA-AgNPs is achieved via FTIR, UV-vis, EDAX, and SEM. Gravimetric, electrochemical (EIS, EFM, DEIS, & TP), and surface assessment (SEM, EDAX, AFM, & XPS) techniques have been deployed in the anticorrosion studies. Results from all applied methods potray GA-AgNPs as effective anticorrosive agent. Inhibition is by adsorption mechanism and follows Langmuir isotherm. GA-AgNPs acts as mixed type inhibitor in 15% H2SO4 solution but as anodic type in 15% HCl solution. Results from surface techniques confirm adsorption of GA-AgNPs molecules on specimen surface. Oxides, hydroxides, carbonates, and sulphates (H2SO4 medium) or chlorides (HCl medium) are the corrosion products in the free corrodent according to XPS results. In the presence of composite, both ionic and neutral forms of GA-AgNPS are adsorbed. AgNPs are present on the surface in the form: Ag°, Ag2O, and AgO.
