The crystals of the title compounds were synthesized by solvent extraction of Hg(Ⅱ) with DB18C6 and TPPO in CHCl~3 solution from KI media, and recrystallization in C~4H~8O~2. They have been studied by melting point determination and TG, IR analysis, and have been structurally characterized by singlecrystal X-ray diffraction techniques. Crystals of the complexes are triclinic, space group P1 with a=1.4211(2), b=1.4488(4), c=1.4934(4)nm; α=113.61(2), β=110.78(1), γ=87.29(2)°. In the crystals, every K is corrdinated by the six oxygen atoms of the DB18C6, one oxygen atom of the TPPO, and every two K are coordinated by two oxygen atoms of the C~4H~8O~2. Dipolymer [(K·TPPO·DB18C6)~2(C~4H~8O~2)]^2^+ cations can be considered to be based on a centrosymmetric bridged dimetric arrangement. Every two Hg were halogen-bridged by two I to be a dipolymer (HgI~3)~2^2^- anions. The anions and the cations arrange in order every other. The other three C~4H~8O~2 fill in the gap of the lattices.

Key words: CRYSTAL STRUCTURE, MERCURY COMPLEX, CROWN ETHER COMPOUNDS, EXTRACTION, DIOXANE