Self-organisation properties of homomeric dipeptides derived from valine

Abstract

Three optically active liquid crystal (LC) homomeric dipeptides, in particular, a pair of enantiomers and a diastereomer formed by joining two half-disc-like entities through a dipeptide spacer comprising L-L, D-D and L-D valine residues, have been synthesised and characterised. Hydrogen-bond-directed self-assembly of these non-discoid supramolecules results in the formation columnar (Col) LC phase. They form a stable organo gel in polar organic solvents through intermolecular hydrogen bond, and their scanning electronic microscopy (SEM) images reveal the presence of entangled network. The interaction of these homomeric dipeptides with nanaoparticles (silica species) has also been investigated by SEM images and UV-visible experiments.

Keywords:

• liquid crystals
• gelation
• hydrogen bond
• amino acids

Acknowledgements

G. Shanker sincerely thanks Dr Martin Jebaraj, Director R & D Centre and Prof. (Dr) K. Mallikarjuna Babu, Principal, BMS College of Engineering, for their support and encouragement. International Iberian Nanotechnology Laboratory (INL), Braga, Portugal is gratefully acknowledged for their help.