Syntheses, crystal structures and magnetic studies of new manganese(II) coordination polymers with ditopic N-pyridinylisonicotinohydrazide ligand and dicyanamide

Abstract

Two new coordination polymers of Mn(II) with dicyanamide anion (dca) and isonicotinohydrazone based ligands, {[Mn2(L1)2(dca)2(CH3OH)2]·H2O}n (1) and [Mn2(L2)2(μ-dca)2]n (2), were synthesized and characterized by elemental analyses and spectroscopic methods where HL1=(E)-N′-(phenyl(pyridin-2-yl)methylene)isonicotinohydrazide and HL2=(E)-N′-(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide. The IR spectra of 1 and 2 show the characteristic stretching vibration bands of a dicyanamide ligand as three bands. Structures of the compounds were characterized by X-ray diffraction analysis which indicates that the isonicotinohydrazone ligands act as a ditopic ligand and coordinate to manganese ions via the N2O-donor set and pyridine group of the isonicotine part. The magnetic susceptibility measurements studies indicated the presence of an antiferromagnetic coupling between high spin Mn(II) ions. Antiferromagnetic coupling for 2 is stronger than that of 1 which is due to connection of Mn(II) ions through dicyanamide bridges in the former.