F-19 and C-13 NMR studies of some pentafluorophenylantimony (III and V) derivatives

F-19 and C-13 NMR studies on a number of pentafluorophenylantimony(III and V) compounds of the type (C6F5)(n)SbX3-n, (C6F5)(n)SbX5-n and C6F5SbBr2Cl2 (X=Cl or Br; n=1-3) have shown that the chemical shift values mainly depend on the oxidation state of antimony (III and V). A marginal yet distinct ef fect on chemical shift has been noticed due to electronegativity difference of halogens (Br, Cl) attached to antimony. The results show standard spin- spin interaction of fluorine atones with respect to o-, m- and p-phenyl pos itions in ring as well as expected chemical shift due to p pi - d pi intera ction of fluorinated benzene ring and antimony. The fluorine of o-position is profusely influenced in comparison to that at p- and m-positions. The fl uorine signals in oxidation stale (III) derivative appear at lower field in comparison to those for oxidation state (V) compounds. The additive effect s of anions and pentafluorophenyl rings seem to be negligible.