Triquinoline- versus Fullerene-Based Cycloparaphenylene Ionic Complexes: Comparison of Photoinduced Charge-Shift Reactions

Abstract

A triquinoline cationic moiety (TQ⋅H⁺ ) has recently been designed as a novel molecular unit for supramolecular chemistry. In addition to some useful features, TQ⋅H⁺ has strong electron-acceptor properties, which renders the molecular cation a unique element in nanochemistry. TQ⋅H⁺ is found to form complexes with coronene (COR) and cycloparaphenylene (CPP). In this work, we report a computational study of photoinduced electron transfer in supramolecular complexes TQ⋅H⁺ -COR, TQ⋅H⁺ ⊂[12]CPP and (TQ⋅H⁺ -COR)⊂[12]CPP. The electron-transfer rates are estimated by using the semi-classical approach. The results are compared with the data previously obtained for a structurally similar inclusion complex Li⁺ @C₆₀ ⊂[10]CPP. In particular, we found a red solvatochromic shift for charge-shift bands in the TQ⋅H⁺ -complexes unlike a blueshift showed by Li⁺ @C₆₀ ⊂[10]CPP. This distinction is explored in terms of electronic and structural features of the systems.

Keywords: charge transfer; density functional calculations; electron transfer; photochemistry; supramolecular chemistry.