THE SPECTRAL AND LUMINESCENT PROPERTIES OF OCTAHYDROACRIDINO[4,3-c] ACRIDIN-1,9(2H,5H)DIONE DERIVATIVES

Abstract

Derivatives of octahydroacridino[4,3-c]acridin-1,9(2H,5H)dione are synthesized using the condensation of diazomethines (N ¹,N ⁵-di-R-benzylidenenaphthalen-1,5-diamines) with dimedone in butanol. The structure of the prepared compounds is confirmed by the methods of nuclear magnetic resonance and IRspectroscopy. The spectral and luminescent properties of the synthesized compounds are studied in ethanol and DMF as solvents at 293 and 77 K. It is found that the absorption spectra are formed by three S_n←S₀ (n = 1-3) electronic transitions and the frequencies of 0-0 transitions from singlet (S₁) and triplet (T₁) states are equal to 24400 and 20800 cm^{- 1} , respectively. The fluorescence quenching by ethanol is due to the formation of the complex with the hydrogen bonds; the lifetime of this complex is less than 10^{- 9} s. Phosphorescence in the studied compounds is caused by the existence of a naphthalenic fragment in the molecule.