A Zr metal-organic framework (MOF) 1-CoCl3 has been synthesized by solvothermal reaction of ZrCl4 with a carboxylic acid-functionalized Co-III-(PNP)-N-N-P-N pincer complex H-4(L-CoCl3) ([L-CoCl3](4-) = [(2,6-(NHPAr2)(2)C6H3)CoCl3](4-) Ar = p-C6H4CO2-). The structure of 1-CoCl3 has been determined by X-ray powder diffraction and exhibits a csq topology that differs from previously reported ftw-net Zr MOFs assembled from related Pd-II- and Pt-II-(PNP)-N-N-P-N pincer complexes. The Co-(PNP)-N-N-P-N pincer species readily demetallate upon reduction of Co-III to Co-II, allowing for transmetalation with late second and third row transition metals in both the homogeneous complex and 1-CoCl3. Reaction of 1-CoCl3 with [Rh(nbd)Cl](2) (nbd = 2,5-nobornadiene) results in complete Rh/Co metal exchange at the supported diphosphine pincer complexes to generate 1-RhCl, which has been inaccessible by direct solvothermal synthesis. Treating 1-CoCl3 with PtC12(SMe2)2 in the presence of the mild reductant NEt3 resulted in nearly complete Co substitution by Pt. In addition, a mixed metal pincer MOF, 1-PtRh, was generated by sequential substitution of Co with Pt followed by Rh.