Synthesis, characterization and ferromagnetic behavior of [Co^III(en)₂(RC₆H₄NH₂)I]I₂.H₂O complexes

Abstract

171-175Mixed ligand cobalt(III) complexes containing aryl amine (RC6H4NH2) ligand have been synthesized using a modified route developed in this study. A wide range of complexes, [CoIII(en)2(L)I]I2.H2O, (where L = RC6H4NH2; R = m-OMe, p-F, H, m-Me, p-Me, p-OEt and p-OMe) show promising reactivities and physical properties due to the presence of electron donor/acceptor groups in the aryl ligand. The complexes have been characterized by elemental analysis, FT-IR, UV-vis and powder X-ray diffraction patterns. FT-IR ν(M-X) and UV-vis spectral data are compatible with trans-form of the complexes. Magnetic studies yield magnetic remanence Mr = 7.071 ´ 10-3 – 3.069 ´ 10-5 emu/g and intrinsic coercivity, -Hci = 141-1156 Oe. Linear regression plot of Mr versus σ yields negative slope, implying that electron withdrawing group in RC6H4NH2 (σ > 0) enhances ferromagnetic character while the electron donating groups (σ 6H4NH2 ligand illustrate a simple molecular fabrication technique, which can be suitably integrated into a system, to have some control on the behavior of metal complexes. A modified ferromagnetic character due to charge build up on the metal centre by ligating nitrogen atom, which in turn makes the molecule into a centre of systematic variation in magnetization, has been observed