CoNaY-zeolite in neat (no solvent) heating of Co-zeolite (350.degreee.C, sealed tube, vac., 2 h), cooling, addn. of tetrafluorophthalonitrile, powdering, evacuation (2 h), heating (300°C, sealed tube, vac., 24 h); extn. (acetone, pyridine, MeCN, acetone; 72 h), drying (90°C, <1 Torr, 15 h); intact complex encapsulated in zeolite;

in further solvent(s) N2-atmosphere, 25percentstoich. excess of tetrafluorophthalonitrile, refluxing in 1-chloronaphtalene (24 h); cooling to room temp., filtration, addn. of petroleum ether, cooling in ice bath (pptn.), filtration, recrystn. (H2SO4);