First, large rod-like crystals of Zn2(dobdc) with lengths of 100s of microns were synthesised via a solvothermal method (Figure ). In these crystals the hexagonal pores run along the length of the rods. The availability of such large crystals ultimately simplifies the PFG NMR analysis, since exchange of CO2 between different crystals and with free CO2 gas becomes negligible on the experimental timescales (typically tens of milliseconds for PFG NMR experiments). With large crystals in hand, the "ex situ static" approach was used whereby a large number of crystals were loaded into a valved NMR tube, which was dosed with 13 CO2, and then taken for static C NMR measurements (Figure ).