title: Stereoisomerism in Nanohoops with Heterogeneous Biaryl Linkages ofE/Z- andR/S-Geometries.
abstract: The stereochemistry of cycloarylene nanohoops gives rise to unique cyclostereoisomerism originating from hoop-shaped molecular shapes. However, cyclostereoisomerism has not been well understood despite the ever-increasing number of structural variants. The present work clarifies the cyclostereoisomerism of a cyclophenanthrenylene nanohoop possessing bothE/Z- andR/S-geometries at the biaryl linkages. Involvement of theR/Saxial chirality in the nanohoop leads to the deviation of the structure from a coplanar belt shape and allows for structural variations with 51 stereoisomers withE/Z- andR/S-geometries. Experimental investigations of the dynamic behaviors of the cyclophenanthrenylene nanohoop revealed the presence of two-stage isomerization processes taking place separately at theE/Z- andR/S-linkages. Consequently, despite the presence ofE/Z-fluctuations, theR/Saxial chirality resulted in a separable pair of enantiomers. The structural information reported here, such as geometric descriptors and anomalous dynamics, may shed light on the common structures of various nanohoops.
authors: Advanced Institute for Materials Research, Tohoku University , Aoba-ku, Sendai 980-8577, Japan.
authors: Parantap
authors: P
authors: Sarkar
authors: Advanced Institute for Materials Research, Tohoku University, Aoba-ku, Sendai 980-8577, Japan; JST, ERATO, Isobe Degenerate π-Integration Project, Aoba-ku, Sendai 980-8577, Japan.
authors: Zhe
authors: Z
authors: Sun
authors: Department of Chemistry, The University of Tokyo, Hongo , Bunkyo-ku, Tokyo 113-0033, Japan.
authors: Toshiki
authors: T
authors: Tokuhira
authors: Advanced Institute for Materials Research, Tohoku University, Aoba-ku, Sendai 980-8577, Japan; Mathematical Institute, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
authors: Motoko
authors: M
authors: Kotani
authors: Advanced Institute for Materials Research, Tohoku University, Aoba-ku, Sendai 980-8577, Japan; JST, ERATO, Isobe Degenerate π-Integration Project, Aoba-ku, Sendai 980-8577, Japan.
authors: Sota
authors: S
authors: Sato
authors: Advanced Institute for Materials Research, Tohoku University, Aoba-ku, Sendai 980-8577, Japan; JST, ERATO, Isobe Degenerate π-Integration Project, Aoba-ku, Sendai 980-8577, Japan; Department of Chemistry, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors: Hiroyuki
authors: H
authors: Isobe