Interactions between multifunctional 2-(2-pyridyl)ethylaminofullerene and proton-donating polymers

Abstract

C60 undergoes nucleophilic addition with 2-(2-aminoethyl)pyridine in chlorobenzene to produce multifunctional 2-(2-pyridyl)ethylaminofullerene (PYEAF) with an average stoichiometry of [C60H8(NHCH2-CH2C5H 4N)8]. PYEAF was mixed with poly(styrenesulfonic acid) (PSSA), poly(vinylphosphonic acid) (PVPA), poly(acrylic acid) or poly(methacrylic acid) in THF/methanol (1/2 v/v) to form fullerene-containing polymer complexes. All complexes do not show distinct glass transitions up to the degradation temperatures. The interactions between PYEAF and the polymers were studied by means of X-ray photoelectron spectroscopy. Protonation of nitrogen in PYEAF was shown by the development of a high-binding energy N1s peak in all complexes. The fraction of protonated nitrogen in the complex depends on the acidic strength and the amount of the polymer. The S2p spectra of PYEAF/PSSA complexes and the P2p spectra of PYEAF/PVPA complexes further show the existence of sulfonate ions and phosphonate ions, respectively. The strong ionic interactions between PYEAF and all these acidic polymers lead to the formation of complexes. © Wiley-VCH Verlag GmbH, 1999.