Characterization of interfacial water in MOF-5 (Zn4(O)(BDC)3)—a combined spectroscopic and theoretical study

Abstract

In this article we report the detection and characterization of adsorbed interfacial water within the cages of the metal–organic framework MOF-5 (Zn₄O(BDC)₃) by terahertz time-domain spectroscopy (THz TDS) in the frequency range from 5 to 46 cm⁻¹. The experimental spectra suggest a coupling of the intermolecular motions of the water molecules adsorbed to the collective vibrations of the network at 4 wt% hydration. This finding is supported by the results of MD simulations. When increasing the water content to 8 wt% we observed a non reversible decomposition of MOF-5.