Sulfite esters as products of the interaction in sulfur dioxide – alkanol – tris(hydroxymethyl)aminomethane systems

Abstract

The reaction products formed in the SO2 – ROH – (HOCH2)3CNH2 (where R – CH3, C2H5, n-C3H7, i-C3H7, n-C4H9 and n-C5H11) systems were isolated and identified as: binary salt – ammonium O-methylsulfite [(HOCH2)3CNH3]+ [CH3OSO2]− (1); 1/1 charge transfer complex between diethyl sulfite (2) and tris(hydroxymethyl)aminomethane by S-N binding; polymorhps of zwitterionic internal salt – O-sulfite tris(hydroxymethyl)methylammonium (at R – n-C4H9 and n-C5H11); and its solvates with n-propanol 1/1 (3) and isopropanol 2/1. The structures of all synthesized products were confirmed by FT-IR, Raman, 1H NMR and 13C NMR spectrometry, and the structure of 1 and 3 was characterized by crystal X-ray diffraction studies as well.