The synthesis of highly fluorinated phthalonitrile resins and cure studies

The reactions of the potassium salts of 1,3- and 1,4-bis(2-hydroxy-hexafluoro-2-propyl) benzene 1 and 2 with tetrafluorophthalonitrile 3 afforded three isomeric products in each case with reaction at the 4-position of 3 predominating. When each mixture was submitted to the usual thermal conditions for phthalocyanine formation [1–5], the expected characteristic color change (blue or green) did not develop. Evidence was procured from our study which indicated that fluorine substituted on the phthalonitrile moieties hindered phthalocyanine formation. Instead, as an alternative reaction, some nucleophilic displacement of fluorine from the aromatic rings by the cyano substituents appeared to have occurred.