SYNTHESIS AND CHEMISTRY OF CYCLIC AND ACYCLIC POLYFLUOROSILOXANES OF 2,2,3,3-TETRAFLUOROBUTANEDIOL AND 2,2,3,3,4,4-HEXAFLUOROPENTANEDIOL

The acyclic disiloxanes [CF(2)CH(2)OSiMe(3)](2) (1) and CF2[CF(2)CH(2) OSiMe(3)](2) (2) and the cyclic siloxanes [CF2CH2O](2)SiMe(2) (3), CF2 [CF2CH2O](2)SiMe(2) (4), and [CF2CH2O](2)SiPh(2) (5) are synthesized b y the reactions of the respective diols with hexamethyldisilazane or b y the condensation reactions with silyl chlorides in the presence of t riethylamine. Reactions of compounds 1-4 with C6F6, (CNF)(3), and CF3C (O)F are found to proceed readily in the presence of catalytic amounts of fluoride ion that liberate Me(3)SiF, Me(2)SiF(2), or Ph(2)SiF(2) t o form cyclic and acyclic fluorinated ethers CC4F4COCH2(CF2)(2)CH2O (6 ), C6F5OCH2(CF2)(3)CH2OC6F5 (7), C6F5OCH2(CF2)(3)CH2OC6F5 (8), C3N3F2O CH2(CF2)(2)CH2OC3N3F2 (9), C3N3F2OCH2(CF2)(3)CH2OC3N3F2 (10), CF3C(O)C H2(CF2)(2)CH2C(O)CF3 (11), and CF3C(O)CH2(CF2)(3)CH2C(O)CF3 (12). 1 re acts with PhPCl(2) even in the absence of catalyst to form the cyclic phosphite (CF2CH2O)(2)PPh (13). The new compounds are characterized by spectral (IR, H-1 and F-19 NMR, MS) and analytical methods. The X-ray crystal structure of the bicylic ether 6 is determined. 6 crystallize s in the monoclinic system, space group P2(1)/n, with a = 9.393(3) Ang strom, b = 10.588(3) Angstrom, c = 11.110(4) Angstrom, beta = 111.42(2 )degrees, V = 1028.7(5) Angstrom(3), d(calc) = 1.990 Mg m(-3), Z = 4, and R = 0.0351.