Sponge-like reversible transformation of a bimetallic cyanometallate polymer

Two new cyano-bridged Ru-Cu polymers, the one-dimensional chain {[Cu(tnH +) 2(H 2O) 2][Ru(CN) 6]·2H 2O) ∞ (1) (where tn = 1,3-diaminopropane) and the pseudo-two-dimensional network {[Cu(tnH +) 2][Ru(CN) 6])} ∞ (2), have been prepared and fully characterized. Compounds 1 and 2 both crystallize in the same monoclinic space group, P2 1/n. Complex 1 was characterized by single crystal X-ray analysis, and compound 2 was characterized by X-ray powder diffraction (XRPD) techniques. Compound 2 was prepared by dehydration of 1; structure 1 can be regenerated by rehydration of 2. The "sponge-like" behavior of this molecular transformation is accompanied by a color change and has been shown by in situ X-ray powder diffraction and immersion calorimetry to be completely reversible. © 2008 American Chemical Society.