Crystal structure of 12H+-2,4-benzo-1,5-dioxa-8,12,16-triaza-cyclooctadec-2-ene-7,17-dione picrate

Abstract

Abstract The title compound [C16H24N3O4]+[C6H2N3O7]- resembles 18 membered macrocycle, which has two ether O atoms, two pairs of amide N and O atoms and an amine N as potential donor atoms. The macrocycle has undergone protonation at the amine N atom. The picrate ion interacts through its phenolic O atom with NH2 + group via N-H⋅⋅⋅O hydrogen bond. NH2 + also shows a strong intramolecular H bonding with one of the amide oxygens of the macrocyclic ring. This results in significant conformational changes in one half of the macrocyclic ring. Apart from it, an increased flexibility of the system and a -CH2⋅⋅⋅π interaction renders the cavity non-suitable for accepting small molecules like water or alcohol in it.