A novel tricyclic tetraaza-substituted 18-crown-6 ligand has been synthesized. The crystal structure of the ligand was determined by X-ray diffraction method. It belongs to monoclinic crystal system with space group P2₁/n, and a＝0.8984(7) nm, b＝1.0805(9) nm, c＝1.1040(9) nm, Z＝2, β＝111.707(13)°, V＝0.9958(14) nm³, D_c＝1.189 g/cm³, μ＝0.092 mm^－1, F(000)＝392, R₁＝0.0649, wR₂＝0.1714. The complexes of this ligand with transition metal ions have been prepared and characterized. The results show that the ligand can form 1∶1 complexes with metal ions Cu^2＋, Zn^2＋, Co^2＋ and Mn^2＋.

Key words: tricyclic structure, tetraaza-substituted crown ether, crystal structure, metal complex