Solvent-assisted linker exchange (SALE) and post-assembly metallation in porphyrinic metal–organic framework materials

Abstract

Using recently reported robust porphyrinic metal–organic framework (RPM) materials, we have examined the systematic exchange of pillaring linkers/struts as a means of accessing new versions of these materials. Dipyridyl-porphyrin Zn(II) (Zn-dipy) struts were successfully replaced by M²-dipy (M² = 2H(+), Al(III), Sn(IV)), forming crystalline solid solutions of Zn(Zn_1−xM_x)-RPM in variable ratios. In addition, post-synthetic metallation was demonstrated using Zn2H-RPM, again with retention of crystallinity. We examined catalytic activity for an epoxide ring-opening reaction with a series of ZnM²-RPMs. The catalytic activity depends strongly on the identity of the metal ion present in the dipyridyl-porphyrin unit.