Rotational and translational dynamics of CO2 adsorbed in MOF Zn2(bdc)2(dabco)

•High translational and rotational mobility of CO2 adsorbed in DMOF-1.•Preferential orientation and diffusion of CO2 in channel direction.•13C residual chemical shift anisotropies derived from MD trajectories.•Predicted diffusion and chemical shift anisotropies confirmed by 13C NMR.

The dynamics of adsorbed CO2 in the metal-organic framework Zn2(bdc)2 dabco (DMOF-1) was investigated using molecular dynamics (MD) simulations and 13C NMR spectroscopy. The statistical analysis of the MD trajectories suggest a preferred localization of the CO2 molecules in the Zn2(bdc)4 corners of the DMOF-1 lattice. The adsorbed molecules retain a high but anisotropic rotational and translational mobility in the channel system. Based on these MD-results, the residual chemical shift anisotropy 〈Δδ〉MD = −114 ppm and the diffusion anisotropy (D∥/D⊥)MD = 9.8 ± 0.5 were calculated. They are found to be in reasonable agreement with the experimental NMR data of 〈Δδ〉NMR=−(55 ± 2) ppm and (D∥/D⊥)NMR = 3 respectively.

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