Abstract-Raman spectroscopy studies of the terahertz vibrational modes of DUT-8 (Ni) metal-organic framework

Alexander S. Krylov,  Alexander Vtyurin,  Petko Petkov,  Irena Senkovska,  Mariia Maliuta,  Volodymyr Bon, Thomas Heine,  Stefan Kaskel,  Evgenia A. Slyusareva

http://pubs.rsc.org/en/Content/ArticleLanding/2017/CP/C7CP06225G?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FCP+%28RSC+-+Phys.+Chem.+Chem.+Phys.+latest+articles%29#!divAbstract


Low-frequency lattice vibration modes have been discussed to play a crucial role in phase transformation process of switchable metal–organic frameworks (MOFs). Therefore, Raman spectroscopy was applied to study lattice dynamics of the pillared layer DUT-8(Ni) framework (DUT – Dresden University of Technology), existing in rigid and flexible form. The open pore phase and the close pore phase could be unambiguously identified by breathing modes bands at 23 cm-1 and 60 cm-1 in the corresponding Raman spectra, showing efficiency of the technique for monitoring the flexibility in MOF materials, as well as on differences in the lattice vibrations of two phases. The Molecular Dynamic simulations showed, that the berating modes correspond to the oscillation of the breathing mode along the diagonals of the pore channels. Moreover, the directional character of low-frequency vibrations in flexible version of DUT-8 could be visualized by orientation dependent Raman spectroscopy experiment.