Investigations on the influence of the coordination formation between dibenzo and benzo derivatives of 18-crown-6 and 15-crown-5 crown ethers with Pr (III) and Nd (III) ions in solution

摘要

In this communication we report the influence of the coordination formation between the dibenzo and benzo derivatives of the crown ethers. The electronic absorption spectra of the derivatives of 18-crown-6 and 15-crown-5 with Pr (111) and Nd (III) ions have been recorded and studied in 1:1,1:2,1:3 and 1:6 metal -ligand ratios in visible range i.e.340-760 nm in solution. The energy and intensity of f-f transitions in these spectra have been quantified and explained in terms the various energy and intensity parameter such as Racah (E~k), Slator-Condon (F_k) Lande (V_(4f)), Oscillator Strength (P) and Judd-Ofelt parameter (T_e) etc. These were computed using partial and regression statistical method. The bonding parameter (b 1/2) and nephalauxetic ratio (b) have also been evaluated. The metal and ligand interaction have been discussed on the basis of these parameters. These parameters suggest the covalent nature of metal and ligand bond.