Hydrogen-bonding pyrrolic amide cleft anion receptors

The use of simple 2,5-diamidopyrrole derivatives as anion receptors has been investigated. Reaction of 3,4-diphenylpyrrole-2,5-dicarboxylic acid chloride with n-butylamine or aniline has produced two new amidic cleft anion receptors 1 and 2. The anion-coordination ability of these species has been determined by 1H NMR titration techniques. Crystal structures of 1 and 2 have been elucidated, revealing a continuous hydrogen bonding network formed by 1 and dimerisation of 2 via NH...O and CH...O hydrogen bonds