Syntheses, structures and inclusion properties of supramolecular dibenzotetraaza[14]annulene hosts for aromatic ring

Macrocyclic compound (E)-Nidmdbdptaa (1) has been synthesized from (E)-Nidmdptaa, a derivative of macrocyclic ligand tetramethyldibenzotetraaza[14]annulene (tmtaa) and benzoyl chloride by the grafting reaction on 6, 13 positions of (E)-Nidmdptaa. The demetallation of 1 leads to its free base, (E)-H₂dmdbdptaa (2). The monobenzoyl substituted macrocyclic analogues of 1 and 2, (E)-Nidmmbdptaa (3) and (E)-H₂dmmbdptaa (4) are also synthesized and characterized, respectively. As well as 2, the introduction of benzoyl groups to nonplanar saddle-shaped (E)-Nidmdptaa changes the awkward shape of 1, forming a supramolecular host for aromatic ring. The single crystal X-ray diffraction analyses show that 1 includes a benzo ring of the adjacent 1 molecule, and 2 clamps a solvent molecule, toluene, by supramolecular weak interactions of van der Waals forces and crystal close packing.