Syntheses, Structures, and Photoluminescent and Magnetic Studies of Metal−Organic Frameworks Assembled with 5-Sulfosalicylic Acid and 1,4-Bis(imidazol-1-ylmethyl)-benzene

Abstract

Four novel interesting coordination polymers, [Cd3(bix)3(SSA)2(H2O)4]n (1), [Co(bix)2(HSSA)(H2O)·H2O]n (2), [Ni(bix)2(HSSA)(H2O)·H2O]n (3) and [Mn(bix)2·(HSSA)·2H2O]n (4) (bix = 1,4-bis(imidazol-1-ylmethyl)-benzene; H3SSA = 5-sulfosalicylic acid), have been synthesized under hydrothermal conditions and structurally characterized. Polymer 1 features a two-dimensional (2D) infinite layer framework built from tri-cadmium clusters, which is further stacked along the c-axis via strong interlayer hydrogen-bond interactions to form a three-dimensional (3D) network. Both polymers 2 and 3 exhibit one-dimensional (1D) double-stranded chains, which are connected by strong hydrogen-bond interactions along the c-axis to result in 2D layers; in addition, the layers are further stacked along the b-axis by π−π interactions. Polymer 4 also possesses 1D double-stranded chains. It is noteworthy that ligand HSSA in compound 4 is not coordinated to the metal ions but only acts as an anion moiety to compensate the charge balan...