title: Hierarchical Self-Organization of Perylene Bisimides into Supramolecular Spheres and Periodic Arrays Thereof.
abstract: Perylene bisimide derivatives (PBIs) are known to form only columnar or lamellar assemblies. There is no known example of a PBI self-assembling into a supramolecular sphere. Therefore, periodic and quasiperiodic arrays generated from spherical assemblies produced from PBIs are also not known. Here, a PBI functionalized at its imide groups with a second generation self-assembling dendron is reported to self-assemble into supramolecular spheres. These spheres self-organize in a body-centered cubic (BCC) periodic array, rarely encountered for self-assembling dendrons but often encountered in block copolymers. These supramolecular spheres also assemble into a columnar hexagonal array in which the supramolecular columns are unexpectedly and unprecedentedly made from spheres. At lower temperature, two additional columnar hexagonal phases consisting of symmetric and asymmetric tetrameric crowns of PBI are observed. Structural and retrostructural analysis via X-ray diffraction (XRD), molecular modeling, molecular simulation, and solid state NMR suggests that inversion of the symmetric tetrameric crowns at high temperature mediates their transformation into supramolecular spheres. The tetrameric crowns of PBIs are able to form an isotropic sphere in the cubic phase due to rapid molecular motion at high temperature, unobservable by XRD but demonstrated by solid state NMR studies. This mechanism of hierarchical self-organization of PBI into supramolecular spheres is most probably general and can be applied to other related planar molecules to generate new functions.
authors.affiliation: Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States.|Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6396, United States.
authors.forename: Dipankar
authors.initials: D
authors.lastname: Sahoo
authors.affiliation: Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States.|Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6396, United States.
authors.forename: Mihai
authors.initials: M
authors.lastname: Peterca
authors.affiliation: Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States.
authors.forename: Emad
authors.initials: E
authors.lastname: Aqad
authors.affiliation: Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States.
authors.forename: Benjamin E
authors.initials: BE
authors.lastname: Partridge
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6396, United States.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Heiney
authors.affiliation: Max-Planck Institute for Polymer Research , 55128 Mainz, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Graf
authors.affiliation: Max-Planck Institute for Polymer Research , 55128 Mainz, Germany.
authors.forename: Hans W
authors.initials: HW
authors.lastname: Spiess
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield , Sheffield S1 3JD, United Kingdom.
authors.forename: Xiangbing
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States.
authors.forename: Virgil
authors.initials: V
authors.lastname: Percec