Two MnII coordination polymers with a triazine-based polycarboxylate ligand: pH value influence, crystal structures and magnetic properties

Two new coordination compounds, [Mn(HL)(H2O)2]n (1) and {[Mn12(L)8(H2O)30]∙10H2O}n (2) were successfully synthesized by using a hydrothermal technique under different pH values and characterized by single-crystal X-ray diffraction. 1 formed at lower pH value (6.0) exhibits 2D lamellar framework which is further connected by hydrogen-bond interactions to construct a 3D supramolecular architecture. Reaction at pH = 7.5 leads to a 2D layered structure of 2, which are formed through the interconnection of the dodecanuclear units and the completely depronated ligands. It is comprehensible that the pH value plays a crucial role in the formation of the resulting structures. Variable temperature magnetic studies down to 2 K reveal antiferromagnetic interactions in complexes 1 and 2.