Crystal‐smectic E mesophases in a series of 2‐(4‐n‐alkylphenyl)indenes

Abstract

A series of 2‐(4‐n‐alkylphenyl)indenes (3) with different alkyl substituents (CH₃ to C₁₀H₂₁) were synthesized and systematically characterized using differential scanning calorimetry, polarizing optical microscopy and X‐ray diffraction compared with 2‐phenylindene (3a). Depending on the alkyl chain length, highly ordered crystal‐smectic E mesophases were observed and confirmed by X‐ray diffraction for the derivatives 3h–3k with heptyl to decyl chains (n = 6−9). For 3f with a pentyl side chain (n = 4), an X‐ray crystal structure analysis was carried out.

Acknowledgements

This work was generously supported by the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie and the Ministerium für Wissenschaft, Forschung und Kunst des Landes Baden‐Württemberg.