Monodisperse liquid crystalline peptides
Solid phase peptide synthesis (SPPS) has been used as a synthetic tool to prepare monodisperse mesogen–oligopeptide conjugates with novel molecular architectures. Building upon previous success in this area, we have extended our methodologies to include a mesogenically substituted l-glutamic acid residue, and incorporated this derivative, as well as the l-lysine derivative previously reported, into a variety of new structures. Some novel liquid crystalline materials have been discovered. Bothalpha;-helical and beta;-sheet secondary structures have been explored as alternative scaffolds for the pendant mesogenic groups. The helical systems show most promise in terms of their ease of synthesis and handling, but at the relatively lower levels of mesogenic substitution studied so far, compared to the previously reported homo-oligopeptide materials, mesophases are not observed. The beta;-sheet materials prepared are rather insoluble and too high melting to have any practical value as thermotropic materials without further manipulation of their structures.