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Block copolymers of unsubstituted poly(p-xylylene)(PPX) and Ge- or Sn-organic bridged PPX (GePPX and SnPPX) were prepared by pyrolysis of specially synthesized organometallic p-cyclophane precursors followed by deposition and polymerization of the thus produced p-xylylene monomers. The copolymer structure and thermal behavior were investigated depending on deposition temperature (10 and -196°C). The copolymer PPX-GePPX obtained from solid monomers deposited at -196 C (2a) consists of long quasi-independent PPX and GePPX blocks and has paracrystalline structure. Thermal treatment of 2a near 160°C yields crystalline regions of PPX along with paracrystalline aggregates of GePPX. Pyrolysis of this system near 300°C in an inert atmosphere results in the formation of Ge crystals in PPX matrix. In contrast, the copolymer PPX-GePPX produced by simultaneous deposition and polymerization at 10°C (2a') contains shorter blocks of PPX and GePPX than the copolymer deposited at -196°C, Copolymer 2a' turns to the amorphous state during thermal treatment, and its pyrolysis does not lead to Ge-crystal formation; hence the supramolecular structure of the polymer plays an important role in inorganic phase formation. The copolymer PPX-SnPPX (2b) is formed only at a deposition temperature of-196°C; deposition at 10°C yields oligomeric resins. The structure of 2b is nearly the same as that of 2a; pyrolysis of 2b in air results in SnO 2 -crystal formation in a PPX matrix.

The HFP trimers (I) and (II) were shown to react readily with thiols in the presence of Et 3 N. Trimer (I) produces vinylic fluorine atom substitution products (IIIa-e) (yields 78-82%). The reaction of trimer (II) with thiols gives corresponding alkyl(aryl)-perfluoropentadienylsulfides (IVa-e) in good yields. The scheme explaining the formation of products (IVa-e) is proposed. The first representative of perfluoroalkylsubstituted thietes - perfluoro-2,4,4-trimethyl-3-isoprophyl-2-thiete (V) is obtained by decomposition of product (IVd). Thiete (V) preparation by a convenient one-part procedure directly from HFPT is also described.

We have shown that the reaction of the trimer of hexafluoropropylene, namely, perfluoro3-isopropyl-4-methyl-2-pentene (I) with tert-butyl mercaptan in the presence of triethylamine gives perfluoro-2,4,4-trimethyl-3-isopropyl-2-thiete (II), which is the first perfluoroalkylthiete reported, in addition to other products. Thiete (II) is the product of the decomposition of intermediate sulfide (A) and is readily separated by distillation in 30.4% yield.