Spectral and Potentiometric Investigation of Nd (Iii) Chelates with Hydroxy Nitrobenzoic Acid

Abstract

pH-metric, thermodynamic and spectral studies of Nd(III) chelates with hydroxybenzoic acid containing nitro group (2-Hydroxy-4-nitrobenzoic acid, 3-Hydroxy-4-nitrobenzoic acid and 4-Hydroxy-3-nitrobenzoic acid) were carried out. The dissociation constant of ligands and stability constants of corresponding metal chelates were determined through Irving-Rossoti pH titration technique at different temperatures (298K, 308K & 318K± 0.1K). Electronic absorption spectra were recorded for various M: L stoichiometry and for different pH for evaluation of intensity and energy parameters of intraconfigurational 4fⁿ transitions. The spectroscopic parameters like Slater-Condon (F_k), Racah (E^k), Lande (z_4f) and Judd-Oflet parameters Ω_λ (λ=2, 4, 6) have been computed using statistical method like partial regression method. IR spectra were recorded for to determine the coordinating sites in metal chelates.