Matrix-isolation FTIR, theoretical structural analysis and reactivity of amino-saccharins: N-(1,1-dioxo-1,2-benzisothiazol-3-yl)-N-methyl amine and -N,N-dimethyl amine

摘要: Abstract In this work, two novel amino-substituted derivatives of saccharin, N -(1,1-dioxo-1,2-benzisothiazol-3-yl)- -methyl amine (MBAD) and , -dimethyl (DMBAD), were synthesized characterized, their molecular structure vibrational properties investigated by matrix-isolation FTIR spectroscopy theoretical calculations undertaken using different levels approximation. The predicted the existence conformers MBAD. lowest energy form was to be considerably more stable than second conformer (Δ E  >  ca. 20 kJ mol −1 ) sole contributing infrared spectrum compound isolated in solid xenon. Both have planar moieties. case DMBAD, only one doubly-degenerated-by-symmetry exists, with nitrogen atom pyramidalized. effect electron-withdrawing saccharyl ring on C–N bond lengths is discussed. structural preferences around molecules explained terms repulsive interactions involving additional methyl group DMBAD. Observed features are correlated reactivity exhibited compounds towards nucleophiles. experimentally obtained spectra matrix-isolated monomers MBAD DMBAD fully assigned comparison corresponding calculated spectra.