Investigation of the terahertz vibrational modes of ZIF-8 and ZIF-90 with terahertz time-domain spectroscopy

The terahertz spectra of ZIF-8 and ZIF-90 were acquired with terahertz time-domain spectroscopy (THz-TDS). Ab initio quantum mechanical calculations yield in spectra that match well with the experimental results and indicate that swing motions in these ZIFs may lie within the terahertz region. Variable temperature THz-TDS measurements on ZIF-90 suggest that the technique is sensitive to host-guest interactions, which can be used to study them in the future.