Two novel topological structures of [Cu(CN)] coordination polymers modified by flexible triazole ligands

Two new cuprous cyanide coordination polymers (CCPs) [{Cu(CN)}(4)(btb)](n) (1) and [Cu(CN)(bth)(0.5)](n) (2) (btb = 1,4-bis(1H-1,2,4-triazol-1-yl) butane, bth = 1,6-bis(1,2,4-triazol-1-yl) hexane) containing flexible triazole ligands were synthesised under hydrothermal conditions and characterized by elemental analyses, IR, UV, XRD, and X-ray structural analyses. In polymer 1, two types of twenty nuclear ring subunits were confirmed by structural analysis. These ring subunits were woven to create an infinite 2D sheet, which was connected by the btb ligands to generate an interesting sandwich structure with (3(1)10(1)13(1))(10(3)) topology. The most remarkable feature of polymer 2 is the 3D ABAB-type stacking structure with (10(2)3(1))(10(5)6(1)) topology, which was constructed by 2D layers with four-membered metal ring units. It is worth noting that all the nitrogen atoms of the ligands in polymers 1 and 2 take part in constructing the title CCPs. In addition, polymers 1 and 2 exhibit certain thermal stabilities and fluorescent properties in the solid state at ambient temperature and a low temperature of 77 K.