in sulfur dioxide absence of air and moisture; condensing excess SO2 onto metal fluoride at -196°C, warming in sealed tube to room temp., stirring for 1 d; evapn. (pumping at dry-ice temp.); yield depending on source of KF;

in neat (no solvent) heating under > 200 hPa SO2;

in neat (no solvent) heating (NPCl2)3 with KSO2F at 120-140 °C; formation of a colorless mixt. of fluoride chlorides;; fractionation;;

in neat (no solvent) formation of PSF3 and a small amount of PSClF2 by react. with KSO2F in an atmosphere of N2;;

in neat (no solvent) refluxing PSCl3 with KSO2F in an atmosphere of N2; formation of two layers in the freezing trap;; the upper layer contains PSF3 and a small amount of PSF2Cl, the other SO2; isolation on distg. at ambient pressure in an atmosphere of N2, use of liquid air and dry ice as cooling agent;;

in neat (no solvent) heating under > 200 hPa SO2;

in nitrobenzene heating a soln. of (NPCl2)3 in C6H5NO2 with solid 90 percent KSO2F on refluxing; react. starting at 100. degree.C under evolution of gas;; condensation of (NPCl2)3 and formed SO2 on cooling with dry ice; isolation on distg. at 0 °C;;

in neat (no solvent) react. of (NPCl2)3 with KSO2F at 120-125 °C;;

in further solvent(s) byproducts: SO2; react. of KSO2F with (Ni(PCl3)4) under exclusion of air and moisture in m-dichlorobenzene (cooling with ice), stirring for 30 min at ambient temp. and for 2 h at 90 °C;; collecting volatile react. products in cooled U-tube (filled with KSO2F), distilling into second U-tube after evapn. of SO2, distillation of (Ni(PF3)4) in micro-column at 760 torr under N2;;

in nitrobenzene heating a soln. of (NPCl2)4 in C6H5NO2 with solid 90 percent KSO2F on refluxing; react. starting at 80. degree.C under evolution of gas;; condensation of (NPCl2)3 and formed SO2 on cooling with ice-water; distn. in vac.;;