Structural investigation of nitrogen-linked saccharinate-tetrazole

► N-(1,1-Dioxo-1,2-benzisothiazol-3-yl)-amine-1H-tetrazole (BAT) is a multidentate ligand. ► Conformational and tautomeric preferences of BAT were investigated in the crystal and isolated in argon matrix. ► Vibrational spectra assigned, for crystalline sample and for matrix-isolated compound. ► The crystal contains the tautomer enabling more favourable intermolecular interactions. ► In the argon matrix, the most stable tautomer predicted by calculations is formed. A conversion mechanism is proposed.