Photocontrolled Living Anionic Polymerization of Silicon-Bridged [1]Ferrocenophanes with Fluorinated Substituents: Synthesis and Characterization of Fluorinated Polyferrocenylsilane (PFS) Homopolymers and Block Copolymers

Photocontrolled living anionic ring-opening polymerization (ROP) of strained silicon-bridged [1]ferrocenophanes Fe(eta-C5H4)(2)SiMe(CH2CH2CF3) (1), Fe(eta-C5H4)(2)SiMe(CH2CH2(CF2)(7)CF3) (2) and Fe(eta-C5H4)(2)SiMe(CH2CH2CH2C6F5) (3) with 3,3,3-trifluoropropyl, heptadecafluoro-1,1,2,2-tetrahydrodecyl, and pentafluorophenylpropyl hydrofluorocarbon substituents, respectively, on silicon, have been explored. Thus well-defined fluorine-containing homopolymers [Fe(eta-C5H4)(2)Si(Me)R-F](n) (4-6) (R-F = hydrofluorocarbon substituents), with controlled molecular weights and narrow molecular weight distributions ((M) over bar (w)/(M) over bar (n) < 110) were synthesized from the photocontrolled ROP of the respective [1]ferrocenophanes 13, initiated by Na[C5H5] in THF at 5 degrees C. The sequential living photolytic anionic ROP allowed the synthesis of well-defined diblock copolymers, polyferrocenylmethylphenylsilane-block-polyferrocenylmethyl(3,3,3-trifluoropropyl)silane (PFMPS-b-PFSF) (7a-c), with different ratios of the two blocks. DSC analysis of the resulting fluorinated diblock copolymers showed the presence of two distinct glass transition temperatures suggesting the immiscibility of the two blocks. The diblock copolymers 7a-c undergo predictable self-assembly in the bulk as revealed by TEM analyses. The increased hydrophobicity of the fluorinated organometallic homopolymers was also studied by measuring the water contact angles on the homopolymer films.