Synthesis, structure and properties of three one-dimensional coordination polymers {[M(II)L(NCS)2](DMF)2}n (M(II)=cadmium(II), zinc(II), manganese(II); L=1,4-bis[2-(2-pyridyl)benzimidazolato]butane)

A tetradentate N-donor ligand 1,4-bis[2-(2-pyridyl)benzimidazolato]butane (L) was prepared for construction of a coordination framework. Three one-dimensional coordination polymers {[M(II)L(NCS)(2)](DMF)(2)}(n) (M(II) = cadmium(II), 1, zinc(II), 2, manganese(II), 3) were obtained by reaction of metal ions and L in the presence of KSCN in DMF/water. The complexes are isostructural and consist of 1D zigzag [M(II)L(NCS)(2)](n) chains and DMF molecules. Within the chains, the metal atoms are each octahedrally coordinated by four N atoms of L and two N atoms of the SCN- anions. Complexes 1 and 2 in the solid state at room temperature exhibit intense photoluminescence at 453 and 433 nm, respectively.