The first 3, 5, 6-trichloropyridine-2-oxyacetate bridged manganese coordination polymer with features of it -it stacking and halogen -halogen interactions: Synthesis, crystal analysis and magnetic properties

A new coordination polymer [Mn(3, 5, 6-tcpa)2(2, 2′-bipy)]n (1) has been synthesized by the hydrothermal reaction of manganese sulfate hydrate with 3, 5, 6-trichloropyridine-2-oxyacetic acid (3, 5, 6-Htcpa) and 2, 2′-bipyridine (2, 2′-bipy) coligands. The X-ray single-crystal diffraction analysis shows that the MnII center is in deformed octahedral geometry bonded by two pyridyl nitrogen atoms of 2, 2′-bipy molecule and four carboxy oxygen atoms of four different 3, 5, 6-tcpa− ligands. The 3, 5, 6-tcpa− anions play as bidentate bridging-μ2 linkers and connect neighbouring MnII ions together to form the 1D double-stranded chain structure of 1, which displays interesting chair form [Mn2(COO)2] eight-membered rings. 1 is further assembled into 3D network by the co-effects of π⋯π stacking and Cl⋯Cl halogen bonds interactions. In addition, the magnetic characterizations indicated weak antiferromagnetic coupling between MnII centers for 1. © 2020 Elsevier B.V.