Investigation of Cycloparaphenylenes (CPPs) and their Noncovalent Ring‐in‐Ring and Fullerene‐in‐Ring Complexes by (Matrix‐Assisted) Laser Desorption/Ionization and Density Functional Theory
Martin B. Minameyer, Youzhi Xu, Stefan Frühwald, Andreas Görling, Max von Delius, Thomas Drewello
Abstract
Abstract [ n ]Cycloparaphenylenes ([ n ]CPPs) with n =5, 8, 10 and 12 and their noncovalent ring‐in‐ring and [ m ]fullerene‐in‐ring complexes with m =60, 70 and 84 have been studied by direct and matrix‐assisted laser desorption ionization ((MA)LDI) and density‐functional theory (DFT). LDI is introduced as a straightforward approach for the sensitive analysis of CPPs, free from unwanted decomposition and without the need of a matrix. The ring‐in‐ring system of [[10]CPP⊃[5]CPP] +. was studied in positive‐ion MALDI. Fragmentation and DFT indicate that the positive charge is exclusively located on the inner ring, while in [[10]CPP⊃C 60 ] +. it is located solely on the outer nanohoop. Positive‐ion MALDI is introduced as a new sensitive method for analysis of CPP⊃fullerene complexes, enabling the detection of novel complexes [[12]CPP⊃C 60, 70 and 84 ] +. and [[10]CPP⊃C 84 ] +. . Selective binding can be observed when mixing one fullerene with two CPPs or vice versa, reflecting ideal size requirements for efficient complex formation. Geometries, binding and fragmentation energies of CPP⊃fullerene complexes from DFT calculations explain the observed fragmentation behavior.