Synthesis and characterization of C60 and C70 acetylacetone monoadducts and study of their photochemical properties for potential application in solar cells

We report on the synthesis of C60 and C70 monoadducts at room temperature through Bingel reaction; employing acetylacetone as ligand; in presence DBU (1,8-Diazabicyclo [5.4.0] undec-7-ene), carbon tetrabromide (CBr4), o-dichlorobenzene. Diacetylmethane-[C60-Ih]-fullerene-[5,6] diacetylmethane-[C70-D5h]-fullerene-[5,6] were obtained with yields 69% 44%, respectively. The products purified by column chromatography (CC, silica gel, using hexane, disulfide, chloroform eluents temperature) characterized Nuclear Magnetic Resonance (1H 13C), Fourier-Transform Infrared (FT-IR) UV-Visible spectroscopies, Matrix-assisted Laser Desorption/Ionization-Time Flight (MALDI-TOF) Mass spectrometry, Cyclic Voltammetry (CV), Osteryoung Square Wave (OSWV). Both compounds showed irreversible reduction peaks controlled diffusion, LUMO energy levels -3.09 eV, -3.13 eV for C60, monoadducts, These values are comparable -3.99 PC61BM. synthetized adducts incorporated into inverted-type perovskite solar cells used electron transporting materials (ETM) obtaining power conversion efficiencies (PCE) 8.5% 14.0% When is replaced a lower symmetrical fullerene such an improved light absorption visible region observed.