UV VIS SPECTROSCOPIC BEHAVIOR OF SOME NEW HYDROXY AZOCOUMARIN DERIVATIVES/

The UV/Vis spectroscopic behaviour of six new hydroxy azocoumarin comp ounds in solution has been investigated. The observed bands are assign ed to electronic transitions. Azocoumarin compounds exist mainly in th e azo form, whereas 6-(2-hydroxy-6-aminonaphthyl-1-azo)-coumarin exhib its an azo-hydrazone tautomeric equilibrium. The solvatochromic behavi our of the azo compounds is investigated by studying their spectra in pure and mixed organic solvents of different characteristics. The long er wavelength band of the azocoumarins in DMF solution is assigned to an intermolecular CT transition.