Mixture diffusion of adsorbed organic compounds in metal-organic frameworks as studied by magic-angle spinning pulsed-field gradient nuclear magnetic resonance

The magic-angle spinning (MAS) and pulsed-field gradient nuclear magnetic resonance (PFG NMR) techniques have been combined using a commercially available microimaging system providing a gradient in the magicangle direction of up to ±2.6 T m -1 , together with a narrow bore MAS probe.By narrowing the spectral linewidths, detection of the single and mixed molecular species adsorbed in porous material and their respective mobilities becomes possible.Here, we report on protocols for MAS PFG NMR measurements, new methods for the indispensable sample alignment along the MAS rotational axis and gradient direction and first experimental results of diffusion studies on nhexane and benzene adsorbed in the metal-organic framework MOF-5.