Influence of Complexing and Excitation Energy on Spectral and Luminescent Properties of 2-Amino-4-Methylphenol

Energy level diagrams of 2-amino-4-methylphenol and its complexes with water are calculated by the method of intermediate neglect of differential overlap (INDO). It is demonstrated that the substitution by the amino group results in the dependence of the quantum fluorescence yield on the excitation energy. The decrease of the quantum fluorescence yield of 2-amino-4-methylphenol in going from hexane to water is explained. Complexing of the 2-amino-4-methylphenol molecule with water with the formation of the H-bond reduces the quantum fluorescence yield compared to the isolated molecule due to the increased efficiency of the S₁ → T₄ conversion.__________Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 71–76, March, 2005.