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

摘要

Two new coordination polymers of Mn(II) with dicyanamide anion (dca) and isonicotinohydrazone based ligands, {[Mn-2(L-1)(2)(dca)(2)(CH3OH)(2)]center dot H2O}(n) (1) and [Mn-2(L-2)(2)(mu-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. (C) 2016 Elsevier B.V. All rights reserved.