“…[16,17,18,19,20] There are many groups of foldamers differing in the type of backbone, with N,N'-linked oligoureas being one example. [21,22,23,24] The N,N'-disubstituted urea group may exist in trans,trans, cis,trans or cis,cis conformations (Figure 1), as the barrier of rotation is lower than for the corresponding amides. [25,26,27] The preferred conformation strongly depends on the structure, but also on the conditions, such as the solvent and the concentration, with the trans,trans or cis,trans conformers being the most populated.…”