Weak ferromagnetism in 1D coordination polymers: Syntheses, crystal structures, spectroscopic and magnetic properties of [Cu(L)(Memal)]n (Memal2− = the dianion of methylmalonic acid, L = 1,10-phenanthroline, 2,2′-bipyridine)

Abstract

Investigation of the CuCl2/H2Memal/L (H2Memal=methylmalonic acid, L=1,10-phenanthroline or 2,2′-bipyridine) reaction system in MeOH and various molar ratios has lead to the isolation of two one-dimensional coordination polymers presenting the [Cu(L)(Memal)] repeating unit (1, L=1,10-phen; 2, L=2,2′-bpy). The Memal2− ligand adopts the bidentate [chelating]+unidentate coordination mode between the CuII ions. Magnetic susceptibility measurements on 1 and 2 indicated the existence of weak ferromagnetic intrachain interactions and X-band EPR spectra from powdered samples of 1 and 2 are consistent with the stereochemistry of the CuII ions and with the presence of weak exchange interactions.