Nanostructures from protected L/L and D/L amino acid containing dipeptides

The self‐assembly of N‐ and C‐protected alternating L/L and D/L amino acids containing dipeptides, Boc‐L‐Val‐L‐Ile‐OMe (1), Boc‐D‐Val‐L‐Ile‐OMe (2), Boc‐L‐Ile‐L‐Val‐OMe (3), and Boc‐L‐Ile‐D‐Val‐OMe (4) has been investigated. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) images indicated that 1 and 3 self‐associated to form highly organized straight net microrods, whereas 2 and 4 self‐assembled to form hexagonal hollow microtube‐like architecture in the acetonitrile‐water medium. To understand the physical basis of such differential behavior, we performed X‐ray diffraction pattern analyses. The single‐crystal X‐ray diffraction (SC‐XRD) study revealed that 1 and 2 self‐assembled to form slightly different helix‐like architectures. The higher‐order association of 2 exhibited a hollow hexagonal tube‐like superstructure. The thermal stability of the nanostructures also varied based on the chiroptical composition of the dipeptides. Experimental findings were corroborated well with computational studies. The obtained results may be helpful in nano‐biotechnology as well as in material science.