Synthesis and electrochemical behaviour of [60]fullerene possessing poly(arylacetylene) dendrimer addends

Abstract

61,61-Bis[4-{3,5-bis(3,5-di-tert-butylphenylethynyl)phenylethynyl}phenyl]-1,2-dihydro-1,2-methano[60]fullerene (10) and 61,61-bis[4-{3,5-bis[3,5-bis(3,5-di-tert-butylphenylethynyl)phenylethynyl]phenylethynyl}phenyl]-1,2-dihydro-1,2-methano[60]fullerene (11) with 1^st and 2^nd generation phenylacetylene dendrimer addends were synthesised according to the Wudl method. Both monoadducts are obtained as single isomers in 18% and 23% yields, respectively. The structures of the products were established by FTIR, ¹H NMR, ¹³C NMR and UV/VIS spectroscopy, as well as by mass spectrometry. All spectroscopic data confirm the exclusive formation of methano[60]fullerenes with [6,6]-closed structures. The electrochemical and spectroelectrochemical properties of 2^nd generation dendrimer 7 and of its fullerene derivative 11 have been investigated. The cyclic voltammetric study shows that no significant interaction occurs in the ground state between the fullerene and the dendrimer; the fullerene derivative retains the typical redox stability of 6,6-closed derivatives in both the cyclic voltammetry (CV) and bulk electrolysis timescales.