C-13 NMR OF ACYCLIC SULFONATED COMPOUNDS INCLUDING SOME FLUOROSULFONIC ACIDS - A CHEMICAL-SHIFT STUDY

A chemical shift analysis of the C-13 NMR spectra of more than 50 acyc lic sulphonic acids, alkali metal sulphonates and methyl esters was ca rried out. Chemical shift increment systems with n-alkanes as referenc e molecules were established for linear alkanesulphonates and alk-2-en esulphonates. Some short-chain fluorinated sulphonic acids were also s tudied, especially pentafluorothio derivatives. C-F spin-spin coupling constants were determined Pauling electronegativity values for SO3H a nd SF5 groups were derived from alpha chemical shift increments.