Synthesis of Copper Corroles as Hole Transporting Material in Perovskite Solar Cells

Abstract

β-Functionalized copper(III) corroles, R8[TPC]Cu where R = bromo, phenyl or methyl, have been synthesized via Pd catalysed Suzuki cross coupling reaction in good to excellent yields and characterized by UV-vis and NMR spectroscopic techniques. The effect of β-substituents on electronic spectral, electrochemical redox and stereochemical properties of the corrole macrocycle has been elucidated. All the synthesized Cu(III) corroles showed saddle-shape conformation. R8[TPC]Cu exhibited red shift in both Q-band and Soret band (Δλmax = 30-40 nm) due to nonplanarity and electron withdrawing nature of bromo substituents while Me8[TPC]Cu exhibited blue shift in Q-band (Δλmax = 4 nm) due to +I effect (inductive effect) of eight methyl group compared to [TPC]Cu. The synthesized corroles, R8[TPC]Cu, are stable at room temperature and can be utilized as hole transporting materials (HTMs) in perovskite solar cells.