N. El-Ghamaz, M. Ghoneim, A. El-Sonbati
2017
Citations
0
Influential Citations
12
Citations
Journal
Journal of Saudi Chemical Society
Abstract
Abstract 4-(4-Amino-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-ylideneamino)-phenol ( L 1 ) and 4-(4-Amino-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-ylideneamino)-benzoic acid ( L 2 ) have been synthesized by the condensation reaction of 4-aminoantipyrine (4-AAP) and 4-aminophenol or 4-aminobenzoic acid in ethanolic solution and are characterized by various physico-chemical techniques. Thin films of L 1 and L 2 have been prepared by the conventional spin coating technique. X-ray diffraction patterns (XRD) show an amorphous nature for both powder and thin films for L 1 and L 2 ligands. The optical absorption and refraction properties of L 1 and L 2 are investigated by spectrophotometric techniques at normal incidence of light in the wavelength range of 200–2500 nm. The absorption spectra show two peaks in the UV region which correspond to π → π ∗ transition and a peak in UV–Vis region which may correspond to n → π ∗ transition. The values of dispersion parameters E o , E d , e L , e ∞ and N/m * are calculated according to the single oscillator model. The presence of the OH group increases the value of e ∞ from 3.21 to 3.32 and the value of N/m * from 7.38 × 10 53 to 2.08 × 10 54 m −3 Kg −1 . The optical band transition is found to be indirect allowing fundamental energy gap values of 3.4 and 3.9 eV and onset energy gap values of 2.1 and 2.6 eV for L 1 and L 2 , respectively.