Self-assembling bis-dendritic peptides: design, synthesis and characterization of oxalyl-linked bis-glutamyl peptides [Glu(n)(CO2Me)n + 1-CO-]2; n = 1,3,7.

Three generations of glutamic acid dendrons [Glu(n),(CO2Me)n + 1; n = 1, 3, 7] have been joined together head-to-head by an oxalyl unit to form highly sterically congested bis-Glu-dendritic peptides with gelling properties. The single crystal X-ray structure of the first generation bis-dendritic peptide showed an extended hydrogen-bonded chiral tape with modest nonlinear optical activity.