FLUORIDE-ION INDUCED REACTIONS OF SILICON-OXYGEN AND SILICON-SULFUR BONDS WITH HEXAFLUOROCYCLOTRIPHOSPHAZENES - SYNTHESIS, REACTIVITY, AND X-RAY STRUCTURAL-ANALYSES OF SULFUR OXYGEN-CONTAINING MONOSPIROFLUOROPHOSPHAZENES/

Bifunctional trimethylsilyl ethers/thioethers/dithioethers react readi ly with N3P3F6 in the presence of a catalytic amount of CsF in THF to yield spirofluorophosphazenes or dangling or bridged fluorophosphazene s with concomitant elimination of Me(3)SiF. With sulfur-containing ali phatic bifunctional reagents of the type Me(3)SiX(CH2)(n)SSiMe(3), fiv e- and six-membered monospirofluorophosphazenes, N3P3F4[X(CH2)(m)S] [X = 0 or S; n = 2 or 3] (1-4), are formed in good yield. Crystals of N3 P3F4[OCH2CH2S] (1) are monoclinic, P2(1)/c; fw = 287.05, a = 8.727(10) Angstrom, b = 11.246(2) Angstrom, c = 9.787(2) Angstrom, beta = 100.9 1(10)degrees, V = 943.2(3) Angstrom(3) and Z = 4. N3P3P4[OCH2CH2CH2S] (2) is orthorhombic, Pbca; fw = 301.08, a = 12.399(4) Angstrom, b = 10 .105(2) Angstrom, c = 16.787(2) Angstrom, V = 2103.3(9) Angstrom(3), Z = 8. N3P3F4[SCH2CH2S] (3) is triclinic, <P(1)over bar>; fw = 303.11, a = 9.501(2) Angstrom, b = 9.764(3) Angstrom, c = 11.099(5) Angstrom, alpha = 74.97 degrees, beta = 88.03 degrees, gamma = 85.85 degrees, V = 991.0(6) Angstrom(3), and Z = 2. N3P3F4[SCH2CH2CH2S] (4) is orthorho mbic, Fdd2; fw = 317.14, a = 18.238(4) Angstrom, b = 41.390(8) Angstro m, c = 5.965(12) Angstrom, V = 4503(2) Angstrom(3), and Z = 16. The P- 31 NMR spectra of these derivatives show a large dependence on the rin g size and an attempt is made to explain this observation on the basis of structural parameters. Reactions of N3P3F6 With disiloxanes such a s (Me(3)SiOCH(2)CH(2))(2)O at temperatures below 80 degrees C yield on ly the dangling product 5a. When the reaction temperature is elevated to similar to 110 degrees C, an oily liquid that is identified as the bridged fluorophosphazene (N3P3F5OCH2CH2)(2)O (5b) is isolated. When [ Me(3)SiOC(CF3)(2)]2C6F4 acts as a bifunctional reagent, a totally fluo rinated bridged phosphazene, [N3P3F5OC(CF3)(2)]2C6F4 (6), forms at sim ilar to 65 degrees C. Aromatic disiloxanes are very facile reagents fo r the formation of spirocyclic products when N2P3F6 is reacted under m ild conditions with the bis(trimethylsilyl) ethers of 1,2-catechol, 3- fluoro-1,2-catechol, 2,3-naphthaienediol, and 2,2'-biphenol. No ring d egradation is observed with 3-F-1,2-C6H3(OSiMe(3))(2) and 1,2-C6H4(OSi Me(3))(2), which give the monospiro derivatives N3P3F4[3-F-1,2-C6H4O2] (7) and N3P3F4[1,2-C6H4O2] (8a) in good yields as well as the dispiro phosphazene derivative N3P3F2[1,2-C6H4O2](2) (8b). Crystals of 8a are orthorhombic Imma; fw = 319.03, a = 7.4642(5) Angstrom, b = 9.5108(7) Angstrom, c = 16.2807(12) Angstrom, V = 1155.78(14) Angstrom(3), and Z = 4; 8b is monoclinic, P2(1)/n; fw = 389.12, a = 10.015 (10) Angstrom , b = 5.612(10) Angstrom; c = 27. 818(4) Angstrom, beta = 96.70 degree s, V = 1552.8(4) Angstrom(3), Z = 4. N3P3F4[2,3-C10H6O2] (9a) is monoc linic, P2(1)/c; fw = 369.09, a = 11.291(2) Angstrom, b = 17.139(3) Ang strom, c = 7.183(10) Angstrom, beta = 101.68 degrees, V = 1361.2(4) An gstrom(3), Z = 4; N3P3F4[2,2'-Cl2H8O2] (10) is monoclinic C2/c; fw = 3 95.12, a = 24.932(5) Angstrom, b = 7.930(10) Angstrom; 18.875(4) Angst rom, beta = 124.55 degrees, V = 3073.6(10) Angstrom(3), Z = 8. The res idual fluorine atoms on the phosphazene rings in 7, 8a, 9a, and 10 can be substituted by fluorophenoxy groups on reaction with the correspon ding o-, m-, or p-(trimethylsilyl)phenoxy ether to give fully substitu ted phosphazenes of the type N(3)P(3)X(OC6H4F)(4) [X = 3-F-1,2-C6H3O2 (11), 1,2-C6H4O2 (12), 2,3-C10H6O2 (13-15), and 2,2'-C12H8O2 (16-18)]. Crystals of N3P3[2,2'-C12H8O2](p-FC6H4O)(4) (18) are triclinic <P(1)o ver bar>; fw = 763.49, a = 10.597(2) Angstrom, b = 12.121(2) Angstrom, c = 15.324(3) Angstrom, alpha = 70.38 degrees, beta = 84.53 degrees, gamma = 65.77 degrees, V = 1688.6(5) Angstrom(3), and Z = 2. The N3P3 core in 18 is distorted and the two biphenoxy rings are twisted at 46. 1 degrees.