Twofold interpenetrating zinc carboxylates framework with isonicotinic acid, and succinate or fumarate as coligands featuring new mixed carboxylate-bridged [Zn2(O2CR)4] dimer as subunits

Two new 3D zinc carboxylates Zn2(suc)(ina)2 (1) (suc = succinate, ina = isonicotinate) and Zn2(fum)(ina)2 (2) (fum = fumarate) have been synthesized under the hydrothermal condition and characterized by the single crystal X-ray diffractions. Both complexes 1 and 2 featuring the [Zn2(CO2R)4] subunit (SBU) formed by mixed tetracarboxylate, interlinked by carboxylate-aromatic amine ligands (ina) to construct a 2D (4, 4) sheet, which are further pillared by rigid or flexible dicarboxylates ligands (suc or fum) into 3D framework. The topology of 1 and 2 can be related to the cubic α-Po twofold interpenetrating lattice. Thermogravimetric analyses demonstrate the similar one-step thermal decomposition process with the tolerate temperature ca. 400 °C of complexes 1 and 2 resulted from the parallel structure motifs and high stability of them.