Pyridyl based mono and di-selenoethers: Synthesis, characterization and DFT study

In this joint experimental-DFT study, we present a robust synthetic methodology, designed to produce Se-C-n-Se and C-Se-C. Three pyridyl based selenoethers were synthesized, characterized and analyzed by applying Density Functional Theory (DFT) calculations and conducting cyclic voltammetry (CV) experiments. Bis(2-(pyridin-2-yl)ethyl)selane (BPSe), 1,3-bis((2-(pyridin-2-yl)ethyl)selanyl)propane (BP3Se(2)) and 1,4-bis((2-(pyridin-2-yl)ethyl)selanyl)butane (BP4Se(2)) were synthesized from different selenocyanates and characterized by FT-IR and C-13, H-1, Se-77 NMR spectroscopies and mass spectrometry. DFT (B3PW91/6-311G(2df,p)) optimized geometries and spectra simulations concur well with the experimental data. Theoretical reactivity behavior was assessed, taking into account HOMO-LUMO diagrams and Molecular Electrostatic Potential maps. Cyclic voltammetry experiments reveal that C-Se bond cleavage occurs in the reduction reaction, whereas, the selenium compounds manifest typical two-electron oxidation behavior. In this work, pyridyl rings were selected to act as electrophile fragments, but from a perspective which considers the possibility of using many other electrophiles to implement this novel procedure. (C) 2019 Elsevier B.V. All rights reserved.