The first case of coronavirus disease 2019 in Colombia was detected on March 6, 2020. Subsequently, schools, colleges, and universities were closed on March 26, which forced a massive migration to virtual education and impacted laboratory-based teaching courses. The teaching of biochemistry requires an experimental component that virtual laboratories cannot emulate.
View Article and Find Full Text PDFThe rate constants for the epoxidation of cis-2-heptene with [2-percarboxyethyl]-functionalized silica (1a) and meta-chloroperbenzoic acid (mCPBA) (1b) in different solvents have been determined at temperatures in the -10 to 40 °C range. The heterogeneous epoxidation exhibits a dependence of the reaction rate on solvent polarity opposite to its homogeneous counterpart and anomalous activation parameters in n-hexane, which are interpreted in terms of the surface-promoted solvent structure at the solid-liquid interface. The results show that highly polar solvents can strongly inhibit heterogeneous reactions performed with silica-supported reagents or catalysts.
View Article and Find Full Text PDF