No abstract

No abstract

The complexation reactions between 4-(2-pyridylazo)resorcinol (PAR) and Al 3+ , Fe 3+ , Zn 2+ , and Cd 2+ ions at 25 °C and 0.1 M ionic strength are performed spectrophotometrically. A critical comparison of the various PCA methods on the absorbance matrix data concerning the number of light-absorbing species has been made. Knowing the number of light-absorbing species is a critical step for subsequent quantitative and qualitative solution equilibria studies. Therefore, the nine selected index functions for the prediction of the number of light-absorbing components which contribute to a set of spectra are critically tested using the algorithms implemented in INDICES software. Behind the number of various complexes formed the stability constants of species ML and MLH, type log β 110 and log β 111 , for the system of PAR (ligand L) with Zn 2+ and Cd 2+ ions and the stability constants of species MLH and ML 2 H, type log β 111 and log β 121 , for the system of PAR (ligand L) with Al 3+ and Fe 3+ ions at 25 °C and 0.1 M ionic strength, and various mole ratios are estimated by the SQUAD and EQUISPEC programs.

No abstract