S-33 NMR-SPECTROSCOPY - SUBSTITUENT GAMMA-EFFECT, HALOGEN-DERIVATIVESOF TETRAHYDROTHIOPHENE 1,1-DIOXIDE

A series of halogen-substituted tetrahydrothiophene 1,1-dioxides (sulp holanes) were investigated by C-13, O-17 and S-33 NMR spectroscopy. It was shown that successive replacement of hydrogen atoms in positions 3 and 4 of the sulpholane ring led to an increase in S-33 nuclei shiel ding, The S-33 NMR chemical shift range exceeded 39 ppm. The variation of the S-33 nuclei shielding with increasing number of chlorine or br omine atoms was caused by an electrostatic through-space effect of the halogen atoms and the strongly polarized C-Hal bonds.