Controlled Morphological Changes in Self-Assembled Structures Formed by Fmoc Variants of Threonine and Serine

We report for the very first time the self-assembly of Fmoc variant 2-(9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-(tert-butoxy)butanoic acid of threonine (Fmoc-Thr(tbu)-OH) and of serine (Fmoc-Ser(tbu)-OH. The self-assembled structure formation of Fmoc variants of threonine and serine were examined under varying concentration and temperature conditions..Our studies reveal that the self-assembled structures formed by Fmoc-Thr(tbu)-OH and Fmoc-Ser(tbu)-OH reveal morphological transitions at the supramolecular level as we alter its concentration and temperature. Fmoc-Thr(tbu)-OH self-assembles to sphere at lower concentration which changes to dumb-bell shapes at higher concentration under room temperature conditions. When the solution at lower concentration is heated the spheres changes to rods while the dumb bell shapes at higher concentrations change to elongated dumb-bell-rod like morphologies. Fmoc-Ser(tbu)-OH on the other hand give flower like morphologies at lower concentration which changes to long rods at higher concentration. On heating at higher temperature 70 ^οC flower-like structures change to small rods while the long rods obtained at higher concentration changes to big flower-like structures. The controlled morphological changes noted in the modified single amino acids is very interesting and pave the way for the design of novel self-assembled architectures for applications in material science and nanotechnology.