Diphenylalanine in tetrahydrofuran: a highly potent candidate for the development of novel nanomaterials

The peptide di-L-phenylalanine (FF) has emerged as a highly potent candidate for the development of novel nanomaterials. The unprotected peptide was dissolved in 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP) mixed with tetrahydrofuran (THF) and single crystals of the THF monosolvate, C₁₈H₂₀N₂O₃·C₄H₈O, were grown by slow evaporation in a `vial-in-closed-bottle' system. THF is a molecule that can only act as a hydrogen-bond acceptor. Thus, the hydrogen-bond patterns observed in the crystal structures at 100 and 299 K are different compared to that of crystals grown from water and methanol [Mason et al. (2014). ACS Nano. 8, 1243-1253].