Spectrophotometric investigation of interaction between iodine and pentadentate Schiff base ligands
| Autor: | Zoulikha Khouba, Tayeb Benabdallah, Ulrich Maschke |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Analytical chemistry
chemistry.chemical_element Electron donor Iodine Ligands Analytical Chemistry Absorption chemistry.chemical_compound Spectrophotometry medicine Instrumentation Spectroscopy Equilibrium constant Schiff Bases chemistry.chemical_classification Schiff base medicine.diagnostic_test Electron acceptor Charge-transfer complex Atomic and Molecular Physics and Optics Kinetics chemistry Physical chemistry Thermodynamics Spectrophotometry Ultraviolet Ionization energy |
| Zdroj: | Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy. 125 |
| ISSN: | 1873-3557 |
| Popis: | The interaction between iodine as an electron acceptor (A), and three pentadentate Schiff bases, 1,3-bis(salicylideneamino)-2-propanol (SB1), 1,3-bis(2-hydroxy-1-naphthylideneamino)-2-propanol (SB2), and 1,3-bis[1-(pyridine-2-yl)methylideneamino]-2-propanol (SB3), as electron donor systems (D), was studied spectrophotometrically in methanol at 28 °C. Equilibrium constants K(AD) and molar extinction coefficients e(AD) of the donor-acceptor complexes (AD) were determined using the modified Benesi-Hildebrand equation in conjunction with the non linear fit analysis. The method shows the formation of 1:1 type complexes as major species in solution. The free energy changes ΔG° and the energy of the charge transfer band E(CT) were also calculated for all complexes. The iodine complex derived from SB2 seems to be more stable than those derived from SB3 and SB1. On the other hand, the ionization potential I(D) of each Schiff base was estimated from the corresponding complex band energy, using an empirical equation. An inverse relationship between I(D) and K(AD) values was found. Blue and red shift observed for the 445 nm band of iodine were also discussed on the basis of theoretical considerations. |
| Databáze: | OpenAIRE |
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