An imprved new method for the synthesis of α, β, β-trifluorostyrene (TFS in THF) was used in the synthesis of six substituted TFS, together with α- and β- trifluoroethenylnaphthalenes. It involves the use of aromatic Grignard reagents with tetrafluoroethylene in THF. The yield of TFS is the highest among the four solvents tried (i.e. THF, ether, DME and dioxane). The structure of all products were established by elemental analysis, IR and ^1^9F NMR The correlations of their F-19 NMR parameters and the concept of "distorted π-electron clouds".

Key words: NMR SPECTROMETRY, NAPHTHALENE P, ETHYLENE P, PARAMETER, ELECTRONIC EFFECT, ORGANO FLUORINE COMPOUNDS, STYRENE P, F19 NMR SPECTROMETRY