Versatile and green synthesis, spectroscopic characterizations, crystal structure and DFT calculations of 1,2,3‒triazole‒based sulfonamides.

A green, and practically reliable method for the synthesis of novel 1,2,3‒triazole-based sulfonamides via copper (I)‒catalyzed azide‒alkyne [3 + 2] cycloaddition reaction was reported. The desired products were characterized by CHN analysis, FT-IR, 1 H and 13 C NMR, ESI-MS spectroscopy, single crystal X-ray diffraction and density functional theory (DFT) geometry optimization and molecular orbital calculations. Mild and green reaction conditions, atom-economic and high yields (61–91%) make this protocol an attractive option for the synthesis of 1,2,3‒triazoles bearing sulfonamide moiety. Geometrical structures, vibrational frequencies, 1 H and 13 C chemical shift values, Mulliken charge distribution and electrophilicity index (HOMO-LUMO analysis) of the characterized structure of 3f in the ground state have been calculated with the aid of DFT studies. The calculated chemical shifts (NMR) and vibrational frequencies (FT-IR) are in compliance with the experimental findings. The aim of the DFT study was to make a reasonable assignment of vibrational bands and chemical shifts. [ABSTRACT FROM AUTHOR]