Tautomerism and IR spectroscopy of arylsulfonamides by quantum mechanical calculations.

Abstract

The molecular structures of sulphonamides are interesting for evaluating their mobility in soils and preparing composite complexes for optimizing the use of these drugs. In this work, the molecular structures of several arylsulfonamides along with conformational analysis and tautomerism were investigated theoretically. The spectroscopical properties of several arylsulfonamides, were also studied at molecular level by using a computational modeling at quantum mechanics level. Besides, the controversial experimental results found in the infrared (IR) spectroscopy bands assignments of solid sulphonamides pushed us up to study computationally the crystal structure of sulfamethazine for clarifying previous assignment discrepancies. The previously proposed polymorphism in the crystal structure of this drug has been also clarified in this work.