Hierarchical Structure of Brucine Inclusion Crystals with Neutral Guest Molecules: Chiral Tapes and their Bundles

ABSTRACT

Brucine inclusion crystals with neutral guest molecules exhibit guest-dependent polymorphism due to a hierarchical structure. Chiral brucine molecules are regarded as a primary structure and assemble to form a chiral tape with a 2₁ axis as a common secondary structure. Such tapes meet together in various modes to constitute different bundles as a tertiary structure. The bundle modes are theoretically classified into eight types, which were screened by alteration of guest compounds in the volume range from 39 to 150 Å³.

Keywords:

• brucine
• bundle
• chirality
• hierarchical structure
• helical tape
• inclusion crystals

Acknowledgments

This work was supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports, and Culture, Japan.

Notes

*Crystal structural data from CSD.