Le vibrateur SO dans les oxo-2 dioxathiannes-1,3,2: dédoublement de bandes par résonance de Fermi et utilisation possible en analyse conformationnelle

Abstract

Forty-seven alkyl-, chloro- or nitro- cyclic sulfites in anancomeric conformation are examined in different solvents and, some at variable temperature through the SO region. Most of them show a doublet SO adsorption assigned to Fermi resonance by the method of solvent variation; this splitting does not arise from the intramolecular association only detected in less substituted molecules with non polar solvents. νSO frequencies are thus deduced and classified in three well localized types according to the three possible orientations of the SO group on a six membered cycle. Bellamy diagrams from eleven compounds indicate that the solvent effect on these frequencies is largely structure dependent. Finally, the integrated molar absorption coefficient of the νSO bands is found nearly constant and independent of the SO orientation.