Photoelectronic properties of dileucine and diisoleucine nanotubes with confined water

The paper presents modeling and quantum-chemical calculations of polar and photoelectronic properties of helix-like peptide nanotubes (PNTs) based on dileucine (LL) and diisoleucine (II) with nanochannels filled with water molecules. Physical properties of LL-based PNTs are close to those of diphenylalnine (FF) PNTs, whereas II-based PNTs demonstrate lower polarization but higher band gap corresponding to the absorption in the UV-C region. Moreover, polarization of LL and II PNTs depends on the chirality of the individual dipeptides and is significantly higher for l-LL and l-II, similar to what is observed for FF PNTs. Water molecules in the internal cavity of PNTs weakly affect their polar properties, whereas noticeably change the HOMO and LUMO energy levels and reduce the bang gap.