Double Hook Perylene Diimide as a New Receptor for PAHs: An Experimental and Theoretical Study

Abstract

AbstractIn a one‐step reaction, we prepared a dibenzylamine perylene diimide derivative (PDI). Its double hook structure allows for self‐association with a constant of Kd ∼108 M−1 determined by fluorescence. We confirmed its ability to bind PAHs using UV/Vis, fluorescence, and 1H NMR titrations in CHCl3. The complex formation signature in UV/vis is a new band at 567 nm. The calculated binding constants (Ka∼104 M−1) follow the trend pyrene>perylene>phenanthrene>naphthalene>anthracene. Theoretical modeling of these systems using DFT ωB97X‐D/6‐311G(d,p) proved helpful in rationalizing the complex formation and the observed association trend. The distinctive signal in UV/vis is due to a charge transfer in the complex from orbitals in the guest to the host. SAPT(DFT) confirmed that the driving forces in the complex formation are exchange and dispersion (π–π interactions). Still, the recognition ability depends on the electrostatic component of the interaction, a minor fraction.