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The hydrothermal preparation via variations of the solvent conditions of Co(NO 3 ) 2 ·6H 2 O with 5-aminoisophthalic dianion (5-NH 2 -bdc) exhibits two new supramolecular isomerism of [Co(C 8 NH 5 O 4 )(H 2 O)] n ·2 n H 2 O ( 1 ) and [Co(C 8 NH 5 O 4 )(H 2 O)] n ( 2 ). The reaction in EtOH/H 2 O resulted in a layered structure of 1 featuring an unusual zigzag water chain between adjacent sheets, and that in H 2 O led to an open 3D framework structure of 2 . The structural data suggest that both the relative orientations in the ligand placement and the donor groups arrangement around the cobalt center are the key factor affecting the patterns of conformational supramolecular isomerism of 1 and 2 . More interestingly, simplified by considering the cobalt dimer and NH 2 -bdc ligand represented an octahedronal node and a triangular node, respectively, structural diversity of 1 and 2 exhibits a structure evidence of 3,6-connecting building blocks with different topologies from 2D ( 4 , 6 3 ) net to 3D Rutile net. Two Complexes exhibit the excellent thermal stability with the tolerate temperature ca. 440 °C for 1 and 410 °C for 2 , respectively, which attribute to the presence of abundant coordination bonds of the μ 4 bridging mode dianion, and the chelate effect of carboxylate groups in the dimer SBUs.

Two new 3D zinc carboxylates Zn 2 (suc)(ina) 2 ( 1 ) (suc = succinate, ina = isonicotinate) and Zn 2 (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 [Zn 2 (CO 2 R) 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.