Synthesis and Physical Properties of Ferrocene Derivatives (XX): Crystal Structure of a Liquid-Crystalline Ferrocene Derivative, 1,1′-bis [9-[4-(4-methoxyphenoxycarbonyl)phenoxy] nonyloxycarbonyl]Ferrocene

Abstract

Single-crystal X-ray structure analysis has been performed for symmetrical 1,1′-disubstituted ferrocene derivative. This compound exhibits liquid crystallinity as a function of temperature with nematic and smectic liquid-crystalline phases. The X-ray structure analysis revealed that two substituents existed in the same directions, and as such induced the cis conformation (“U” shape) of the molecule. The molecules in the unit cell are arranged in a bookshelf manner. Within each layer, CH-π intermolecular interaction was observed at the substituents between neighboring molecules. It is considered that this interaction plays a predominant role in stabilizing the crystal packing arrangement and the mesomorphism.

Keywords:

• crystal structure
• 1,1′-disubstituted ferrocene derivative
• ferrocene
• liquid crystal
• metallomesogen

ACKNOWLEDGMENT

A High-Tech Research Center Project for Private Universities matching fund subsidy from MEXT (Ministry of Education, Culture, Sports, Science and Technology), 2002–2005 is gratefully acknowledged for partial support of the present work. We are grateful to T. Hanasaki and K. Uno, Ritsumeikan University, Japan, for useful discussion.