Synthesis, characterization and ferromagnetic behavior of [CoIII(en)2(RC6H4NH2)I]I2•H2O complexes

Mixed ligand cobalt(Ill) 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]I-2 center dot 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 v(M-X) and UV-vis spectral data are compatible with trans-form of the complexes. Magnetic studies yield magnetic remanence M-r = 7.071 X 10(-3) - 3.069 x 10(-5) emu/g and intrinsic coercivity, -H-ci 141-1156 Oe. Linear regression plot of M-r versus a yields negative slope, implying that electron withdrawing group in RC6H4NH2 (sigma > 0) enhances ferromagnetic character while the electron donating groups (sigma < 0) reduce ferromagnetism. The study provides evidence that substitution at the aryl ligand, remote from the Co(III) center, effectively displays and imparts characteristic ferromagnetic properties. Cobalt(III) complexes containing RC6H4NH2 ligand illustrate a simple molecular fabrication technique, which can be Suitably integrated into a system, to have some control oil the behavior of metal complexes. A modified ferrorriagnetic 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.