Crystals of the layered metal organic framework solid Pb[B(IM)(4)](NO3)(nH(2)O) can undergo exchange of the nitrate for perrhenate, a model for pertechnetate, forming Pb[B(Im)(4)](ReO4). We can monitor this reaction by Pb-207 solid-state NMR and can isolate single crystals of the resultant material through growth in the presence of an excess of perrhenate. Such a synthetic metal-organic framework solid represents a new candidate for pertechnetate-sequestering materials.