Structural Diversity for a Series of Metal(II) Complexes Based on Flexible 1,2-Phenylenediacetate and Dipyridyl-type Coligand

To systematically investigate the factors that influence the formation of various metal(II) complexes, dual systems containing a flexible benzene dicarboxylate and two kinds of dipyridyl-type coligands are assembled into six metal(II) complexes, formulated as {[Zn(phda)(bpa)]·(H2O)3}n (1), {[Zn2(phda)2(dpe)2]·(H2O)}n (2), [Co(phda)(bpa)(H2O]n (3), [Co(phda)(dpe)]n (4), [Mn(phda)(bpa)(H2O)]n (5), and [Mn(phda)(dpe)0.5(H2O)]n (6) (phda = 1,2-phenylenediacetate, dpe = 1,2-di(4-pyridyl)ethylene, and bpa = 1,2-bi(4-pyridyl)ethane). The X-ray single crystal diffractions show that the formed six complexes reveal a diversified structure topology under the regulation of two kinds of dipyridyl-type coligands and are further divided into three complex pairs based on the nature of metal cations. Each pair of complexes is assembled from the same metal cation and different dipyridyl-type coligands to produce disparate structures respectively: the three-dimensional (3D) metal–organic frameworks of zinc complex pairs (1, 2) feature a single dia net with permanent porosity when the free solvent molecules are evacuated and a 4-fold interpenetrated dia net with dense structure, respectively; cobalt complexes pairs (3, 4) exhibit a two-dimensional (4,4) grid and a 3D self-penetrated framework with (48668) rob net, respectively. Both manganese complex pairs (5, 6) display (4,4) grids except that the former contains linear metal carboxylates and the latter consists of ribbonlike metal carboxylates. In addition, thermal stability of complex 1, luminescent properties of the zinc complex pairs (1, 2), and magnetic properties of complexes 4 and 6 are also systematically investigated.