Vapor-triggered reversible crystal transformation of a nickel-based magnetic molecular switch.

Vapor-triggered crystal-to-crystal transformation between a discrete trinuclear complex [Ni 3 (sih) 2 (py) 8 ] and a two-dimensional (2D) coordination polymer [Ni 3 (sih) 2 (py) 2 ] n ·2DMF·2H 2 O was demonstrated. It provides an example of a solid-state coordination-induced spin state switch behavior attributed to the structural phase transition triggered by solvent signal. The reversible nature can be detected by both optical (spectral) and magnetic responses in cycles.