Synthesis, crystallographic characterization, DFT and TD-DFT studies of Oxyma-sulfonate esters

Abstract

Three oxyma sulfonate esters were prepared using dichloromethane-water (two-phase method) in the presence of sodium carbonate for scavenging HCl. The products were characterized by FT-IR, NMR ( $$^{1}\hbox {H}$$ and $$^{13}\hbox {C}$$ ), UV-Vis spectra and elemental analysis. X-ray single crystal diffraction experiments proved the molecular structures of three esters. Their molecular structures were also calculated using DFT/B3LYP method. The optimized structures agreed well with the X-ray structures. Time-dependent density functional theory (TD-DFT) was used to assign the electronic absorption bands observed experimentally. Pyridine derivative showed two bands at shorter $${\uplambda }_{\mathrm{max}}$$ compared to the others, both experimentally and theoretically. The NMR chemical shifts were computed for protons and carbons using GIAO method, which correlated well with the experimental data. Natural charges, dipole moments and chemical reactivity of these molecules, as well as their non-linear optical activity, were computed and compared. SYNOPSIS An eco-friendly method was used to synthesise three oxyma-sulfonate esters using two-phase (dichloromethane-water) method in presence of sodium carbonate for scavenging HCl. The oxyma sulfonate esters were characterized using different spectroscopic techniques (FT-IR, NMR, UV-Vis) as well as X-ray single crystal diffraction analysis. The electronic and spectroscopic properties of these esters were computed using DFT/B3LYP method .