Two metal–organic frameworks {[Zn₂(DSBDC)(dpp)₂](H₂O)₂}_n (1) (H₄DSBDC = 2,5-disulfonylterephthalate acid and dpp = 1,3-di(4-pyridyl)propane) and [Cd₂(SBTC)(dpp)_1.5]_n (2) (H₄SBTC = 5-sulfonyl-1,2,4-benzenetricarboxylic acid) with novel sulfonate–carboxylate ligands have been synthesized and structurally characterized. The in situ formation of the H₄DSBDC ligand derived from H₄SBTC is unprecedented and involves a fundamentally new substitution of sulfonate for carboxylate in the in situ ligand synthesis reaction. The solid state structures of 1 and 2 consist of neutral 2D metal aromatic sulfonate–carboxylate layers, which are pillared by the dpp ligands to generate different 3D architectures. The topological structure of 1 is a trinodal net based on three kinds of topologically equivalent 4-connected nodes with the Schläfli symbol of (6⁴.8²). The framework of 2 can be classified as a 4,5,6-connected 3D net with the Schläfli symbol of (4³.6³) (4³.6⁵.8²) (4⁶.6⁶.8³). In the solid state, compounds 1 and 2 exhibit white-ish and blue photoluminescences, respectively.