Solid state structural studies of saccharin salts with some heterocyclic bases

Abstract

Five saccharin salts with heterocyclic bases 1,2-bis(4-pyridyl)ethane, 1; trans-1,2-bis(4-pyridyl)ethylene, 2; piperazine, 3; 1,4-dimethylpiperazine, 4 and 2,2′-dipyridylamine, 5 have been synthesized and characterized by single crystal X-ray diffraction. The crystal structures reveal that in all the salts, the hydrogen atom has been transferred from saccharin nitrogen to the base nitrogen and sustained through charge-assisted hydrogen bonds. In salts 1–3, N⁺–H donor forms N⁺–H⋯O hydrogen bonds with the carbonyl oxygen of saccharinate, whereas it forms N⁺–H⋯N⁻ in 4 and intramolecular N⁺–H⋯N in 5. Salts 2 and 3 also form weak N⁺–H⋯N⁻hydrogen bonds. Only in salt3, the SO₂ moiety is involved in conventional hydrogen bonding.