γ-graphynes with extended polyyne chains for efficient photoinduced electron transfer in complexes with fullerenes

Abstract

In recent years, much attention has been paid to -graphynes due to their high potential in practical applications. The unique combination of sp2-sp carbon atoms, an extended π-conjugated structure and evenly distributed dehydrobenzo[n]annulene pores provide excellent performance of -graphynes in gas separation, water purification, sensors, and catalysis. In this work, we report the ground and excited state properties of -graphyne, -graphdiyne, and -graphtriyne and their non-covalent complexes with fullerenes. Our results demonstrate that the non-covalent complexes are stable and exhibit low mobility of C60 across the graphtriyne sheet. The electron-withdrawing ability of these materials is enhanced by passing from -graphyne to -graphtriyne, which assists in photoinduced electron transfer from endohedral fullerenes to graphyne. The process is found to occur on a sub-nanosecond time scale in the complexes of -graphdiyne and -graphtriyne with Sc3N@C80. These theoretical results provide useful insights for the development of carbon materials for photovoltaic applications