Electronic and Optical Properties of Paracyclophanes

Paracyclophanes (PCPs) offer tunable electronic and optical properties through through-space interactions, yet their excited states, especially charge-transfer (CT) states, are difficult to model accurately. We present a computational framework combining CC2 and range-separated TD-DFT with solvation to achieve balanced accuracy for locally excited and CT states. A proposed fragment-based excitonic description reduces computational cost while preserving quantitative reliability. Applied to pyrene-naphthalene diimide PCPs, the approach reveals how linker-controlled geometry governs CT formation, exciton coupling, and optical response, enabling quantitative simulation of spectra and excited-state properties.