New mixed-linker metal–organic framework (MOF) materials incorporating both carboxylate and hydrazone linkers were prepared. The zinc-based 3D MOFs were obtained by utilizing a presynthesized aroylhydrazone [4-pyridinecarbaldehyde isonicotinoyl hydrazone (PCIH)] and para-dicarboxylic acids [1,4-benzenedicarboxylic acid (H₂BDC) and 4,4′-biphenyldicarboxylic acid (H₂BPDC)]. Single-crystal X-ray diffraction revealed the interpenetrated, pillar-layered structures of the MOFs, including layers formed by dicarboxylate-bridged Zn₂nodes as well as hydrazone pillars. The microporous [Zn₂(dcx)₂(hdz)₂]·guests frameworks (dcx = linear dicarboxylate dianion; hdz = hydrazone) were found to adsorb CO₂selectively over N₂upon thermal activation. The frameworks represent rare MOFs of the type [Zn₂(dcx)₂(pil)₂] (pil = neutral pillar), in which two pillars at each metallic site of the Zn₂node connect adjacent layers.