  We present the frequency-dependant (dynamic) dielectric response of a group
of topical polycrystalline zeolitic imidazolate-based metal-organic framework
(MOF) materials in the extended infrared spectral region. Using
synchrotron-based FTIR spectroscopy in specular reflectance, in conjunction
with density functional theory (DFT) calculations, we have revealed detailed
structure-property trends linking the THz region dielectric response to
framework porosity and structural density. The work demonstrates that MOFs are
promising candidate materials not only for low-\k{appa} electronics
applications but could also be pioneering for terahertz (THz) applications,
such as next-generation broadband communications technologies.
