Lattice dynamics in non-crystalline and crystalline metal organic frameworks

We propose to measure the phonon dispersion relations in a series of metal-organic framework (MOF) materials which vary from crystalline to non-crystalline depending on the functionalization of their organic building units. Typically, the dynamics of crystalline materials are seen as markedly different from those of non-crystalline materials. We propose to measure 3 members of the MOF-5-CX series, spanning periodic and non-periodic variants, and MOF-5 to compare the non-crystalline materials with crystalline controls. We want to answer the question: Do the unconventional non-periodic materials studied show crystal-like dispersion relations or glass-like continua of excitations? This study is expected to provide valuable insights into the dynamics of highly complex disordered framework materials.