Synthesis and Physical Properties of Ferrocene Derivatives (XIX): Crystal Structure of a Liquid-Crystalline Ferrocene Derivative, 9-[4-(4-Methoxyphenoxycarbonyl)-phenoxycarbonyl] nonyl 4-Ferrocenylbenzoate

Abstract

The molecular and crystal structures of a metallomesogen, 9-[4-(4-methoxyphenoxycarbonyl) phenoxycarbonyl]nonyl 4-ferrocenylbenzoate, have been determined. The space group was monoclinic with the P2₁/a, and Z = 4. An eclipsed conformation of two cyclopentadienyl rings was observed in the ferrocenyl moiety. The flexible spacer was an almost all-trans conformation. The largest value of the dihedral angle between the two phenyl groups in the mesogenic group was observed throughout all the homologues. This result shows that even if the dihedral angle in the mesogenic group is large, the mesophase can be exhibited by elongating the molecular length. The molecular packing arrangement was similar to those of liquid-crystalline homologues.

Keywords:

• crystal structure
• ferrocene
• liquid crystal
• metallomesogen
• monosubstituted ferrocene derivative

ACKNOWLEDGMENT

A High-Tech Research Center Project for Private Universities matching fund subsidy from the 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 helpful suggestions.