The Magnetic Properties of d8 -d10 β-Diketonate Supramolecular Metal Complexes and Their Macromolecular Polymers

Abstract

The field-dependent magnetization M(H) of [M(tba)2·nH2O] supramolecular metal complexes and their [M(tba)2(4,4′-bipy)]n (M ˭ Ni(II), Cu(II), and Zn(II); tba = deprotenated 3-benzoyl-1.1.1-triflouroacetone (H-tba); 4,4′-bipy = 4,4′-bipyridine) macromolecular coordination polymers have been investigated by vibrating sample magnetometer at ambient temperature (ca. 23°C). The external magnetic field H(Oe) was applied in the range of 0−100 Oe. The magnetization M(emu/g) was equal almost to zero without an applied magnetic field (H(Oe)) for each metal ion. The increase or decrease in the slope of the magnetization curve (M(H)) with the H(Oe) was nearly linear as is usually true for paramagnetic and diamagnetic materials. The coordination of 3-benzoyl-1.1.1-triflouroacetone (H-tba) with Ni(II) and Cu(II) metal ions produces [M(tba)2(H2O)2] (M ˭ Ni(II) and Cu(II)) complexes that have paramagnetic properties less than their metal acetates. The slope of the M(H) curve for the [Ni(tba)2(H2O)2] metal complex was found to be higher than for the [Cu(tba)2] complex. The diamagnetic behavior of [Zn(tba)2(H2O)2] was not highly affected by the H-tba ligand. The extending of the paramagnetic metal complexes using 4,4′-bipyridine produces diamagnetic [Ni(tba)2(4,4′-bipy)]n and [Cu(tba)2(4,4′-bipy)]n macromolecular polymers possessing a negative magnetization (M(emu/g)) values. It was found that the [Zn(tba)2(4,4′-bipy)]n polymer has diamagnetic properties higher than the [Zn(tba)2(H2O)2] complex.