While the one-pot approach worked well for Ni(II) and Cu(I), generalizing this strategy to other metal cations was challenging due to the precipitation of insoluble PyCHO-containing metal species. In an effort to expand our metalation catalogue, we returned to the stepwise route. Initial attempts to form iminopyridine species in the absence of Lewis acidic transition metal salts yielded poor conversion to the imine (e.g., <50% yield after 7 days). Surprisingly, simply switching from the nonpolar solvents commonly used in the MOF literature (e.g., DCM, toluene) to a more polar solvent such as methanol greatly improved the yield. Heating 1-NH2-18% in methanol with a large excess of 2-pyridinecarboxaldehyde (50 equiv) resulted in the clean formation of 1-IP-18%, with a BET surface area of 2450 m 2 /g (Fig. ). The reaction could be tracked by digestion 1 H NMR. Though the digestion conditions hydrolyze the imine, the observed 1:1 ratio of 2pyridinecarboxaldehyde to H4dotpdc-NH2 is consistent with quantitative imine formation (Fig. ). The loss of the broad amine N-H stretch at ~3590 cm -1 is clearly observed in the ATR-FTIR spectra, further supporting the conversion of the amine to the imine (Fig. ).