title: Zero thermal expansion in a flexible, stable framework: tetramethylammonium copper(I) zinc(II) cyanide.
abstract: Tetramethylammonium copper(I) zinc(II) cyanide, which consists of N(CH(3))(4)(+) ions trapped within a cristobalite-like metal cyanide framework, has been studied by variable-temperature powder and single-crystal X-ray diffraction. Its coefficient of thermal expansion is approximately zero over the temperature range 200-400 K and comparable with the best commercial zero thermal expansion materials. The atomic displacement parameters, apparent bond lengths, and structure of a low-temperature, low-symmetry phase reveal that the low-energy vibrational modes responsible for this behavior maintain approximately rigid Zn coordination tetrahedra but involve significant distortion of their Cu counterparts.
authors.affiliation: School of Chemistry, The University of Sydney, NSW 2006, Australia.
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Phillips
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Halder
authors.forename: Karena W
authors.initials: KW
authors.lastname: Chapman
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Goodwin
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: Kepert