FLUORINATED CYCLOTHIAPHOSPHAZENES - SYNTHESIS, STRUCTURE AND REACTIVITY

Reaction of chlorocyclothiaphosphazenes NPCl2(NSOX)(2) (X = Cl, Ph) an d (NPCl2)(2)NSOX (X = Cl, F, Ph) with KSO2F in bulk leads to fluorinat ion at the phosphorus centers. The substitution reaction follows a gem inal pattern. Reactions of trans-NPF2(NSOPh)(2) with Grignard reagents RMgX (R = Me, (t)Bu) show substitution of fluorine by alkyl groups to be a slow process. The more reactive PhMgBr gives an acceptable react ion rate and good yields. Organolithium reagents offer organo-substitu ted cyclothiaphosphazenes in low to moderate yields, depending on the reagent used. Crystals of cis-NPF2(NSOPh)(2) are monoclinic, space gro up P2(1)/n, with a = 13.665(7) Angstrom, b = 10.676(1) Angstrom, c = 9 .897(3) Angstrom, beta = 90.55(3)degrees, V = 1443.8(9) Angstrom(3), a nd Z = 4. The final R and wR values are 0.034 and 0.043, respectively. The PN and SN bond lengths vary from 1.571(2) to 1.590(2) Angstrom.