Reversible solid-state structural conversion between a three-dimensional network and a one-dimensional chain of Cu(II) triazole coordination polymers in acidic/basic-suspensions or vapors.

New Cu(II) triazole coordination polymers with a 3D network were synthesized and reversible structural conversion between a 3D network and a 1D chain with color change was realized by pH controlled acidic and basic-suspensions or vapors. For each conversion process of decreasing and increasing pH, conversion was accomplished with high yield, in which the crystal before conversion played the role of a solid-state crystal template.