2 e 251 3 3 u03bd sub 5 f sub 2g 84 0 3 lattice vibration__________________________________________________________________________ nf 4 snf 5 is a white crystalline hygroscopy solid stable at room temperature and decomposing above 200 u00b0 c its characteristic x ray powder pattern is listed in table iv table iv______________________________________x ray powder data for nf sub 4 snf sub 5d obsd int d obsd int______________________________________7 72 mw 2 571 mw6 32 vs 2 519 vw5 69 w 2 276 w5 29 w 2 146 w4 51 m 2 064 ms4 19 m 1 965 mw3 80 vs 1 929 w3 46 m 1 820 m3 32 m 1 780 mw3 17 mw 1 757 mw2 868 w 1 732 mw2 802 w 1 700 mw2 743 m 1 661 vw2 683 w 1 639 w 1 615 w______________________________________ its ionic structure i e presence of nf 4 cations was established by its 19 f nmr spectrum in brf 5 solution in addition to the solvent lines it showed the triplet see above at u03c6 220 characteristic of nf 4 two resonances were observed for snf 5 at u03c6 145 4 and 162 4 respectively with an area ratio of 1 4 at 20 u00b0 c the resonances consisted of broad lines but at lower temperatures the u03c6 162 4 signal showed splittings based on a more detailed analysis of these data the snf 5 anion appears.