To investigate the role of the capping group in the solution and solid-state self-assembly of short peptide amphiphiles, dialanine and diphenylalanine have been linked via the N-terminus to a benzene (phenyl) and 3-naphthyl capping groups using three different methylene linkers; (CH2)n, n=0–4 for the benzene and 0, 1 and 2 for the naphthalene capping group. Atomic force microscopy (AFM), oscillatory rheology, circular dichroism (CD), and IR analysis have been employed to understand the properties of these peptide-based hydrogels. Several X-ray structures of these short peptide gelators give useful conformational information regarding packing. A comparison of these solid state structures with their gel state properties yielded greater insights into the process of self-assembly in short peptide gelators, particularly in terms of the important role of C···H interactions appear to play in determining if a short aromatic peptide does form a gel or not.
- C⋅⋅⋅H interactions
- Hirshfeld surface analysis
- aromatic peptide amphiphiles
- hydrogen bonding
Farahani, A. D., Martin, A. D., Iranmesh, H., Bhadbhade, M. M., Beves, J. E., & Thordarson, P. (2019). Gel- and solid-state-structure of dialanine and diphenylalanine amphiphiles: importance of C···H interactions in gelation. ChemPhysChem, 20(7), 972-983. https://doi.org/10.1002/cphc.201801104