Tetrafluorophthalonitrile 97%3,4,5,6-Tetrafluorobenzene-1,2-dicarbonitrile3,4,5,6-Tetrafluoro-1,2-benzenedicarbonitrileTetrafluorophthalonitrile3,4,5,6-四氟邻苯二甲腈四氟邻苯二腈3,4,5,6-四氟邻苯二腈tetrafluorobenzene-1,2-dicarbonitrile1,2-Dicyano-3,4,5,6-tetrafluorobenzene