Spectral and Thermal Studies of Light Lanthanide Complexes with 4-Methoxy-3-nitrobenzoic Acid

4-Methoxy-3-nitrobenzoates of light lanthanides with a metal to ligand ratio of 1:3 have been obtained as hydrated salts. They have colours typical of Ln3+ ions (Pr-green, Nd-pink, Sm-cream, and La, Ce, Eu and Gd-white). The carboxylate group appears to be a bidentate chelating ligand. 4-Methoxy-3-nitrobenzoates of light lanthanides are crystalline compounds. During heating in air, they decompose explosively. Therefore, their thermal stability was studied in the temperature range 273–523 K. The complexes dehydrate in one or three steps. The solubilities of complexes were measured in water at 293 K. They are in the order of 10–4 mol dm–3

Magnetic, thermal and spectroscopic features of 2,3- and 3,5-dimethoxybenzoates of Co(II), Ni(II) and Cu(II)

The 2,3- and 3,5-dimethoxybenzoates of Co(II), Ni(II) and Cu(II) were synthesized as solids and their magnetic, spectral and thermal properties studied. The complexes are hydrated or anhydrous compounds which possess colours typical of the M(II) ions. Their thermal stabilities were examined in air and nitrogen and the gaseous and solid state decomposition products were also identified. The magnetic susceptibilities of the complexes weremeasured over the temperature range 4.4–300 K and the magnetic moments were calculated. The results show that the 2,3- and 3,5-dimethoxybenzoates of Co(II) and Ni(II) are high-spin complexes with weak ligand fields, and that the complexes of Cu(II) form dimers

Spectral, thermal and magnetic characterization of 2,3-dimethoxybenzoates of Co(II), Ni(II) and Cu(II)

Complexes of 2,3-dimethoxybenzoates of Co(II), Ni(II) and Cu(II) have been synthesized as hydrated or anhydrous polycrystalline solids and characterized by elemental analysis, IR, FIR and electronic spectroscopy, magnetic studies and X-ray diffraction measurements. The carboxylate groups bind as monodentate or symmetrical, bidentate chelating and bridging ligands. The thermal stabilities were determined in air. When heated they dehydrate to form anhydrous salts which are decomposed to the oxides of the respectivemetals. Themagnetic susceptibilities of the complexes weremeasured over the range 77–300 K and themagnetic moments were calculated. The results show that the complexes of Ni(II) and Co(II) are high-spin complexes and that of Cu(II) forms a dimer