A continuing tale of chirality: metal coordination extended axial chirality of 4,4′-bipy to 1D infinite chain under cooperation of a nucleotide ligand

Abstract

1D and 2D homochiral nucleotides coordination polymers UMP/CMP-4,4′-bipy-M(II) (M = Co, Cu, Ni) 1–5 were designed, synthesized and analyzed by the single-crystal X-ray diffraction method. Axial chirality of 4,4′-bipy is captured and extended to a 1D infinite chain due to metal coordination and cooperation of a chiral nucleotide inducer, which is defined as Extended Axial Chirality (EAC) for the first time. Different chiral sources coexist in these nucleotide coordination polymers and can be observed clearly in solid-state circular dichroism (CD) spectroscopy, including the inherent chirality of ligands, extended axial chirality and supramolecular helical chirality. Furthermore, 2D complexes of CMP-bipy-Cu (3) present dominant Cu(II)⋯Cu(II) magnetic exchange through (–O–P–O–) and bipy bridge, exhibiting ferromagnetic interactions.