Bicontinuous cubic phase with the Pn3m space group formed by N,N,N-tris(5-alkoxytroponyl)-1,5,9-triazacyclododecanes

Abstract

N,N,N-tris(5-alkoxytroponyl)-1,5,9-triazacyclododecanes and their corresponding benzenoids were synthesised to investigate their mesomorphic properties. The troponoids have a bicontinuous cubic phase with a Pn3m space group whereas the benzenoids form a smectic A phase. The thermal stability of the cubic phase of the troponoids is decreased when the length of the alkyl group is increased whereas that of the smectic A phase of the benzenoids behaves reversely. The cubic phase of the troponoid should represent an organisation of the fluid alkyl chains within the interwoven networks whereas the polar azacrown and tropolone units should form the continuum.

Keywords:

• bicontinuous cubic phase
• Pn3m space group
• troponoid liquid crystals
• azamacrocyles

Acknowledgements

We thank Professors K. Ohta (Shinshu University, Japan) and S. Kutsumizu (Gifu University, Japan) for discussions.

Notes

1. Number (n) of molecules is calculated by the equation of n = (σVN)/M, where σ: density, which is assumed as 1 g/cm³, V: volume (72.0 × 10⁻⁸ cm³), N: Avogadro's number, M: molecular weight (1203.99).