A one-dimensional copper(II) coordination polymer constructed by pyridyl-2,5-dicarboxylate: Helical structure and magnetic property

Hydrothermal synthesis of pyridyl-2,5-dicarboxylate (H2L) and Cu(II) salt in the mixed solvents of water and pyridine (py) afforded one unusual 1D coordination polymer, [Cu4(L)4(py)4], with neighboring left- and right-handed helical chains. Strong π–π packing and Cu⋯O interactions found among neighboring chains lessen the inter-chain Cu⋯Cu distances to about 3.83 Å. Magnetic measurements show a ferromagnetic exchange with the 2J value of 27.7 cm−1.

► 1D coordination polymer with neighboring left- and right-handed helical chains.
► Strong π–π packing, Cu⋯O interactions, and short inter-chain Cu⋯Cu distances among neighboring chains.
► A modest ferromagnetic exchange with the 2J value of 27.7 cm−1.