Barium, potassium, and tris(ethane-1,2-diamine)nickel (II) fluoroalkanedisulfonates and the X-ray crystal structures of K-2(O3S)(2)CHF, K-2(O3S)(2)CF2, K-2(O3S)(2)(CF2)(3)center dot H2O, and [Nien(3)][(O3S)(2)(CF2)(n)] (n=1,3)

The barium perfluoroalkanedisulfonates Ba(O3S)(2)(CF2)(n) (n = 1, 3-5) and the new potassium fluoroalkanedisulfonates K-2(O3S)(2)CHF, K-2(O3S)(2)CF2, and K-2(O3S)(2)(CF2)(5) have been prepared by reaction of (CF2)(n)(SO2F)(2) (n = 1, 3-5) or CHF(SO2F)(2) with CaO (or Ca(OH)(2)) and M(OH)(x) (M = Ba, x = 2; M = K, x = 1) or with Ba(OH)2 alone (n = 1) in water. In each of th e crystal structures of K-2(O3S)(2)CHF and K-2(O3S)(2)CF2, there is an eigh t-coordinate and a six-coordinate potassium ion, whilst in K-2(O3S)(2)(CF2) (3)H2O, two different eight-coordinate potassium ions are linked by a bridg ing water molecule. One potassium has additionally six sulfonate oxygen and one fluorine donor atoms. and the other, five sulfonate oxygens and two fl uorine donor atoms. The preparation of highly crystalline [Nien(3)][(O3S)(C F2)(n)] (en = ethane-1,2-diamine; n = 1, 3-5) and the X-ray crystal structu res for n = 1 or 3 provide evidence for the value of perfluoroalkanedisulfo nate ions as counter ions for the crystallization of cationic complexes.