Compositional inhomogeneity and tuneable thermal expansion in mixed-metal ZIF-8 analogues

Research output: Contribution to journalArticle


  • Adam F. Sapnik
  • Harry S. Geddes
  • Emily M. Reynolds
  • Andrew L. Goodwin
  • Hamish Yeung

Colleges, School and Institutes

External organisations

  • MRC Health Data Research UK (HDR UK), London, UK.
  • University of Oxford


We study the structural and thermomechanical effects of cation substitution in the compositional family of metal–organic frameworks Zn1−xCdx(mIm)2 (HmIm = 2-methylimidazole). We find complete miscibility for all compositions x, with evidence of inhomogeneous distributions of Cd and Zn that in turn affect framework aperture characteristics. Using variable-temperature X-ray powder diffraction measurements, we show that Cd substitution drives a threefold reduction in the magnitude of thermal expansion behaviour. We interpret this effect in terms of an increased density of negative thermal expansion modes in the more flexible Cd-rich frameworks.


Original languageEnglish
Pages (from-to)9651-9654
Number of pages4
JournalChemical Communications
Issue number69
Early online date1 Aug 2018
Publication statusPublished - 7 Sep 2018