Synthesis and characterization of soluble poly (ferrocenylenearylene)s from condensation of dilithio bis(alkylcyclopentadienide) arenes with iron(II)halides: A general route to conjugated poly(metallocene)s
Ge. Southard et Md. Curtis, Synthesis and characterization of soluble poly (ferrocenylenearylene)s from condensation of dilithio bis(alkylcyclopentadienide) arenes with iron(II)halides: A general route to conjugated poly(metallocene)s, ORGANOMETAL, 20(3), 2001, pp. 508-522
Bis(alkylcyclopentadienyl)arenes have been prepared by sequential lithiatio
n/alkylation of dibromoarenes with alkylcyclopenta-2-en-1-ones. The resulti
ng dicarbinols were dehydrated with p-toluenesulfonic acid to give the bis(
alkylcyclopentadienyl)arene. Poly(alkyl-1,1'-ferrocenylenearylene)s were pr
epared by the reaction of dilithio bis(alkylcyclopentadienide)arenes and ir
on(II) salts in THF. The resulting polymers were oxidized with iodine to gi
ve the fully oxidized polyionomers. The polyionomers were found to give mix
ed-valence polymers when allowed to equilibrate with neutral polymers in so
lution, provided the degree of oxidation, N, lies between ca. 0.55 and 1.0.
For degrees of oxidation 0.0 < N < 0.55, disproportionation occurs to give
neutral polymer and polymer with N approximate to 0.55. The oxidized polym
ers showed small to moderate antiferromagnetic interactions, and some were
found to follow non-Curie-Weiss behavior that is ascribed to the complex ma
gnetic properties of individual ferrocenium centers rather than to any type
of magnetic ordering. The organic bridging ligands and polymers were chara
cterized by TGA-DSC, GPC, NR, CV, FT-IR, and UV-vis techniques. The fully o
xidized and mixed-valence polymers were characterized by magnetic susceptib
ility, FT-IR, EPR,Mossbauer, and UV-vis spectroscopies.