Synthesis and optical properties studies of antipyrine derivatives thin films

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.