Electronic Structure and Absorption Properties of Strongly Coupled Porphyrin–Perylene Arrays

Porphyrin–perylene arrays are ideal candidates for light-harvesting systems capable of panchromatic absorption. In this work, we employ density functional theory (DFT) and time-dependent DFT to investigate the unique UV–vis absorption properties exhibited by a series of ethynyl-linked porphyrin–perylene arrays that were previously synthesized and characterized spectroscopically [Chem. Commun. 2014, 50, 14512−5]. We find that the ethynyl linker is responsible for strong electronic coupling of porphyrin and perylene subunits in these systems. Additionally, these arrays exhibit a low barrier to rotation around the ethynyl linker (