title: Chiral pinwheel clusters lacking local point chirality.
abstract: The supramolecular pinwheel cluster is a unique chiral structure with evident handedness. Previous studies reveal that the chiral pinwheels are composed of chiral or achiral molecules with polar groups, which result in strong intermolecular interactions such as hydrogen-bonding or dipole interactions. Herein, it is shown that the simple linear aromatic molecule, pentacene, can be self-assembled into large chiral pinwheel clusters on the semimetal Bi(111) surface, due to enhanced intermolecular interactions. The pentacene pinwheels reveal two levels of organizational chirality: the chiral hexamers resulting from asymmetric shifting along the long molecular axis, and chiral arrangement of six hexamers with a rotor motif. Furthermore, a new relation between the local point chirality and organizational chirality is identified from the pinwheels: the former is not essential for the latter in 2D pinwheel clusters of the pentacene molecule.
authors.affiliation: School of Physical Science and Technology & MOE Key Laboratory on Luminescence and Realtime Analysis, Southwest University, Chongqing, P.R. China.
authors.forename: Kai
authors.initials: K
authors.lastname: Sun
authors.forename: Ting-Na
authors.initials: TN
authors.lastname: Shao
authors.forename: Jia-Le
authors.initials: JL
authors.lastname: Xie
authors.forename: Meng
authors.initials: M
authors.lastname: Lan
authors.forename: Hong-Kuan
authors.initials: HK
authors.lastname: Yuan
authors.forename: Zu-Hong
authors.initials: ZH
authors.lastname: Xiong
authors.forename: Jun-Zhong
authors.initials: JZ
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Qi-Kun
authors.initials: QK
authors.lastname: Xue