Syntheses and crystal structures of supramolecular compounds of tetranuclear Zr~(IV) and Hf~(IV) aqua hydroxo complexes with macrocyclic cavitand cucurbituril

摘要

Slow evaporation of hydrochloric acid solutions of zirconium(IV) or hafnium(IV) oxochlorides and cucurbituril in air afforded compounds with composition [M_4(OH)_8(H_2O)_(16)]C1)3·(C_(36)H_(36)N_(24)O_(12))·16H_2O,where M=Zr (1) or Hf (2).According to the X-ray diffraction data,complexes 1 and 2 are isostructural.Their crystal structures can be described as packings of polymer chains consisting of alternating cucurbituril molecules and tetranuclear cations [M_4(OH)_8(H_2O)_(16)]~(8+) linked to each other via an extensive network of hydrogen bonds.Compound 2 is the first structurally characterized tetranuclear hafnium aqua complex.