Lattice Dynamics of Highly Porous Materials

Highly porous materials such as MOFs, COFs and HOFs have been shown to have promising electronic and dielectric properties.^1-3 However, high levels of porosity often couple with low structural stability.^4,5 Therefore, the collective lattice dynamics reveal a diversity of valuable information relating to the structural flexibility and the mechanistic origins of anomalous mechanical phenomena.^6-8 Spectroscopic techniques such as inelastic neutron scattering (INS), in conjunction with DFT, are used to study the phonon mode dynamics, including those related to gate opening and breathing,⁶ trampoline-like mechanisms and molecular rotors reminiscent of negative thermal expansion (NTE),^7,8 and buckling of 2D layers.⁹ The work has also revealed the effect of external stimuli (pressure and temperature) and shown stimuli-induced phase transitions and amorphization.^9-11

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5. Phys. Chem. Chem. Phys., 18, 9079 (2016)
6. Phys. Rev. Lett., 113, 215502 (2014)
7. Phys. Rev. Lett., 118, 255502 (2017)
8. CrystEngComm, 18, 4303 (2016)
9. Ind. Eng. Chem. Res., 5823, 9883 (2019)
10. Adv. Theory Simul., DOI:10.1002/adts.201900093
11. Chem. Commun., 53, 7041-7044 (2017)