ELECTRONIC SPECTRAL BEHAVIOR OF SOME NEW HYDROXY AZOCOUMARIN DERIVATIVES

The spectral behaviour of six new hydroxy azocoumarin compounds has be en Investigated in solution. The bands appearing in the UV and Visible regions are assigned to the possible electronic transitions. It is ev ident that azocoumarin compounds are found to exist mainly in the azo form, while 6-[2-hydroxy-6-aminonaphthyl-1-azo] coumarin exist in the azo-hydrazone tautomeric equilibrium. The solvatochromic behaviour of the azo compounds is investigated through studying their spectra in pu re and mixed organic solvents of different characteristics. The longer wavelength band displayed by the azocoumarin in DMF solution is assig ned to an intermolecular CT transition.