Structural analysis and magnetic properties of the 1-D compounds [M(NCS)2bpa2] [M = Fe, Co, Ni and bpa = 1,2-bis(4-pyridyl)ethane]

Abstract

The increasing interest in designing polymeric compounds has focused this work on the synthesis and magnetostructural characterization of three 1-D compounds of general formula [M(NCS)₂bpa₂] [M = Fe, Co, Ni and bpa = 1,2-bis(4-pyridyl)ethane] which exhibit double bpa bridges between metallic cations. X-Ray single crystal diffraction analysis was carried out on 1 [Fe(NCS)₂bpa₂] while for 2 [Co(NCS)₂bpa₂] and 3 [Ni(NCS)₂bpa₂] the structural characterization was performed on powdered samples. UV-VIS results were consistent with high-spin metallic cations in tetragonally distorted octahedral fields. Although in the three compounds weak antiferromagnetic coupling has been observed taking place through the –M–(bpa)₂–M– bridges, for the theoretical analysis of the global magnetic behaviour of all of them some other effects have been considered, i.e. zero field splitting and spin–orbit coupling.