Alkylated [6,6]-open difluoromethanofullerenes C60(CF2)R2: Facile synthesis, electrochemical behavior and photovoltaic applicationsстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 30 декабря 2016 г.
Аннотация:Incorporation of the CF2 bridge into fullerene cages allows fine tuning of the boundary levels and endows bridgehead sites with enhanced reactivity in the anionic state. Further functionalization at those sites provides additional level tuning capabilities, which can give rise to promising acceptor-type building blocks for organic electronics. Here we report the regioselective synthesis, spectral and structural characterization of novel C60(CF2)R2 dialkyl derivatives (RCH3, allyl, benzyl, CH2C6F5, CH2CO2Et), as well as their electrochemical behavior. The reported compounds can be reversibly reduced up to the trianionic state. Experimental electrochemical and DFT estimation of the HOMO and LUMO levels revealed that the energy of the frontier orbitals is increased as compared to C60 making these compounds prospective for application as acceptor materials in polymer solar cells (PSCs). Testing the corresponding prototypical PSCs demonstrated that among the C60(CF2)R2 derivatives the highest power conversion efficiency was observed for C60(CF2)(CH2CO2Et)2 which exhibits better solubility and photoactive layer morphology.
Keywords: homofullerene; alkylation; structure elucidation; cyclic voltammetry; electronic structure; polymer solar cells