Discrete π‐Stacks from Self‐Assembled Perylenediimide Analogues. (12th September 2019) - Su, Feng
Abstract: The formation of well‐defined finite‐sized aggregates represents an attractive goal in supramolecular chemistry. In particular, construction of discrete π‐stacked dye assemblies remains a challenge. Reported here is the design and synthesis of a novel type of discrete π‐stacked aggregate from two comparable perylenediimide (PDI) dyads (PEP and PBP ). The criss‐cross PEP ‐PBP dimers in solution and (PBP ‐PEP )‐(PEP ‐PBP ) tetramers in the solid state are well elucidated using single‐crystal X‐ray diffraction, dynamic light scattering, and diffusion‐ordered NMR spectroscopy. Extensive π–π stacking between the PDI units of PEP and PBP as well as repulsive interactions of swallow‐tailed alkyl substituents are responsible for the selective formation of discrete dimer and tetramer stacks. Our results reveal a new approach to preparing discrete π stacks that are appealing for making assemblies with well‐defined optoelectronic properties. Abstract : Doppelgänger : Eine diskrete π‐Stapelung aus zwei vergleichbaren Perylendiimid(PDI)‐Dyaden (PEP und PBP) wurde synthetisiert. PEP‐PBP‐Dimere in Lösung und (PBP‐PEP)‐(PEP‐PBP)‐Tetramere im festen Zustand werden durch Röntgenbeugung, dynamische Lichtstreuung und NMR‐Spektroskopie aufgeklärt. Die chromophoren Doppelgänger „umarmen" sich über π‐π‐Interaktionen und bilden so stabile diskrete π‐Stapel.