Electrical, And Magnetic Characteristics Of Homo- And Hetero-Bimetallic Macromolecular Complexes With Pi-Conjugated Imine-Oxime Backbone

Seven homo- and hetero-bimetallic macromolecular complexes (BMCs) were prepared via an in-situ multi-step complexation reaction of Cu-II, Ni-II and Fe-III metal centers with imine- oxime pi-conjugated ditropic spacer (1,4-phenylene-bis(2,3-butanedeimineoxime, L2-). The structures of the obtained [M-L-2-M](x), [M`-L-2-M`](x), [M-L-2-M`](x) and their mu-oxo-[M-L-2-Fe](x) BMCs (M = Cu-II, Ni-II; M` = Fe-III) were elucidated using different spectroscopic (UV-Vis, FT-IR), powder X-ray diffraction (p-XRD) and microscopic (SEM) techniques. The SEM images indicate that the obtained BMCs exhibit nano/micro globular and rod-like textures. The electrical and magnetic characteristics of the obtained BMCs can be described as magneto-semiconducting materials. The structural, electrical, and magnetic properties inherited in the prepared regime demonstrate that the examined semiconducting pi-spacer has clear ability to semi-conduct electron transport and delocalize spin leading to antiferromagnetic coupling, thus offering a favorable magnetic exchange pathway between the paramagnetic metal sites. However, ferromagnetic enhancement is observed in the mu-oxo-[M-L-2-Fe](x) BMCs where the mu-oxo-bridge overplays the role of the pi-spacer. A magnetic responsive thin film was conveniently obtained by solvent casting of the mu-oxo-[Ni-L-2-Fe](x) BMC in a transparent poly(methamethylacrylate) matrix.