Study of Solvent Effects on the Uv/Visible Spectra of A Newly Synthesized Azo-Dye5-(8-Quinaldinolazo)-Para Phenyl Acetic Acid

The solvent effect can be determined by Solvent polarity scale, solvatochromic parameter which has different position of UV-Visibile absorption band in the range between 300 nm to 600 nm. The spectral characteristics of this azo dyes(QAPA) in different solvents at room temperature was analyzed which is the aim of studying the effect of solvents on the absorption spectra of this dyes in organic solvent of different characters. The solvatochromic behaviors of (QAPA) dye and solvent ̸ solute interactions can be analyzed by means of linear(solvation). The absorption spectra was(QAPA) dyes found to be two main bands at which 435nm which saw that Transition π-π* of the-N=N-group show a hypsochromic shift and550nm with n-π* transition This band is found to be highly dependent on solvent polarity and it shows a bathochromic shift with increasing solvent polarity, which may be indicated in azo-enaminetautomers. So, the absorption at longer wavelengths may be assigned to the hydrazone tautomer or common anion form. Absorption maxima of dyes are dependent on solvent polarity. Solvation of dye molecules probably occurs via dipole-dipole interactions in non-hydrogen-bond donating solvents, In hydrogen-bond donating solvents the phenomenon is more hydrogen bonding in nature.