A neutron diffraction study of structural changes in one-dimensional K2Pt(CN)4Br0.3 · 3H2O from 77–323°K

Single crystal neutron diffraction measurements of K₂Pt(CN)₄Br_0.3 · 3H₂O (KCP) above room temperature, to the point of irreversible crystal breakdown (318–323°K), and at liquid nitrogen temperature (77°K), give no indication of a crystallographic phase change. Full three-dimensional data collected at 77°K ($\text{a = 9.848(5)}\text{A}\text{?}\text{, c = 5.714(3)}\text{A}\text{?}\text{,}\text{and space group}\text{P4mm}$) indicate that the structure is essentially unchanged from that at room temperature except for increased hydrogen bonding association between H₂O(2) and Br(1). The possible relationship between the hydrogen bonding changes and Br(1) site ordering is discussed.