Solvent-controlled assembly of manganese(II) tetrachloroterephthalates with 1D chain, 2D layer, and 3D coordination Architectures

With solvent molecules participating in coordination systems, four new Mn-II coordination polymers of the rigid ligand 2,3,5,6-tetrachloro-1,4-benzenedicarboxylic acid (H2BDC-Cl-4) have been obtained from different solvent media. Single-crystal X-ray analysis indicates that the coordination arrays of 1-4 vary from 1D fishbone or zigzag chain for 1 or 2, 2D (4,4) layer for 3, to 3D SrAl2 coordination network for 4, respectively. In {[Mn(BDC-Cl-4)(py)(2)(H2O)(2)]((PY))(2)}(n) (1) and {[Mn(BDCCl4)(MeOH)(3)](MeOH)}(n) (2), pyridine/water (in 1) and MeOH (in 2) molecules act as the monodentate terminal ligands to fulfill the metal coordination spheres. In the case of ([Mn(BDC-Cl-4)(dioxane)(H2O)(2)](dioxane)}(n) (3), the aqua ligand is monodentate and the dioxane moiety displays unusual bridging bidentate mode, whereas for [Mn-5(BDC-Cl-4)5(DMF)(5)](n) (4), three Mn-II centers are connected by four BDC-Cl-4 ligands and two DMF molecules to constitute a trimeric unit. These secondary units are extended to the final 3D network with SrAl2 (sra) topology. Significantly, the solvents play an essential role in the crystallization and construction of these coordination frameworks with distinct dimensionality and connectivity. The thermal and photoluminescence properties of complexes 1-4 in the solid state have also been discussed.