Nitrate directed organized assemblies of protonated arene based tripodal receptors

Abstract

Three tripodal and one dipodal receptors with benzene platform and heterocyclic terminals have been chosen to study nitrate and chloride dependent aggregation properties in their protonated states. A detailed single-crystal X-ray diffraction study showed the formation of nitrate (planar) ion assisted capsular/distorted capsular/macrocyclic structures in cases of tripodal receptors and 1D-zigzag polymeric chain in the case of the dipodal receptor. Single crystal structures of two of the tripodal receptors show that the spherical anion like chloride failed to form a capsular aggregate. Furthermore, the nitrate complex of the dipodal receptor reveals the solid state structural evidence of the uncommon hydrogen dinitrate anion where the central hydrogen atom is in a general position midway between two nitrate oxygen atoms.