Synthesis of poly(ferrocenyldialkoxysilane) polymers and their introduction into oxide matrices

The synthesis of 1,1′-ferrocenediyldialkoxysilanes Fe(η-C5H4)2Si(OR)2M2–M5 (R=i-Pr, t-Bu, PhCH2, Me), consisting of the reaction between 1,1′-ferrocenediyldichlorosilane with the selected alcohols, is described. The thermal ring opening polymerisation of M2–M5 yielded the corresponding poly(ferrocenylsilane) polymers P2–P5. These linear polymers were soluble in polar solvents and exhibited high molecular weights. The monomers M2 and M4 were introduced into a silica matrix by a non-hydrolytic sol–gel process. However, SiC bond breaking was observed due to the electrophilic ipso substitution. Polymers P3 and P4 were easily condensed with SiBr4. When P3 was condensed with TiCl4 and AlCl3, degradation of the polymer occurred. Interestingly, the hydrolytic sol–gel polycondensation of polymers P2, P4 and P5 yielded a completely polycondensed hybrid solid, without significant specific surface area and with conservation of the electrochemical properties.