Designing anisotropic cyanometallate coordination polymers with unidirectional thermal expansion (TE): 2D zero and 1D colossal positive TE

Abstract

Oxidative addition of halogens to tetracyanoplatinate results in the formation of a Pt(IV)-building block that, combined with Cu(II), forms coordination polymers Cu(H₂O)₂[PtX₂(CN)₄] (X = Br, Cl). These materials exhibit directional anisotropic thermal expansion: nearly zero expansion within the cyanometallate sheets and positive thermal expansion in the third dimension.