Synthesis, Structures, and Sorption Properties of Two New Metal–Organic Frameworks Constructed by the Polycarboxylate Ligand Derived from Cyclotriphosphazene

[Image: see text] Solvothermal reactions of hexakis(4-carboxyphenoxy)cyclotriphospazene (H(6)L1) with copper ions in DMF/H(2)O produced one complex, {[Cu(6)(L1)(2)(OH)(H(2)O)(3)]·guest}(n) (1), but with copper ions and auxiliary rigid 4,4-bipyridine (bpy) produced another new complex, namely, {[Cu(3)(L1)(bpy)(H(2)O)(6)]·guest}(n) (2). These complexes had been characterized by IR spectroscopy, elemental analysis, and X-ray structural determination. 1 exhibits a 3D anionic structure with the binodal 4,8-connected network with Schläfli symbol {4(6)}(2){4(9)·6(18)·8}, consisting of Cu(6) clusters and L1 ligands. In contrast, complex 2 possesses a different 3D network with trinodal 3,4,6-c topology with Schläfli symbol {4·6(2)}(2){4(2)·6(6)·8(5)·10(2)}{6(4)·8·10}. In these two complexes, the semirigid hexacarboxylate ligands adopt distinct conformations to connect metal ions/clusters, which must be ascribed to the addition of the auxiliary rigid ligand in reaction systems. In addition, gas absorption properties of 1 and 2 including CO(2) and N(2) were further investigated.