The intracrystalline concentration
profiles during molecular uptake of methanol by an initiallyempty, single crystal of microporous manganese(II) formate (Mn(HCO
2)
2), representing an ionic inorganic-organic hybrid within the MOF family, are monitored by interference microscopy. Within these
profiles, acrystal section could be detected where over the total of its extension (
![](/images/entities/ap.gif)
2
![](/images/entities/mgr.gif)
m × 50
![](/images/entities/mgr.gif)
m × 30
![](/images/entities/mgr.gif)
m) molecularuptake ideally followed the pattern of one-dimensional diffusion. Analysis of the evolution of intracrystallineconcentration in this section directly yields the permeability of the crystal surface and the intracrystallinediffusivity as a function of the concentration of the total range of 0
![](/images/entities/le.gif)
0.57 covered in the experiments.Within this range, the surface permeability is found to increase by 1 order of magnitude, while, within thelimits of accuracy (±30%), the transport diffusivity remains constant, thus reflecting the properties of thelattice gas model.