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Luminescence-spectral and acid-base characteristics of 3-aryl-7-diethylaminocoumarins

Research paper by N. S. Patalakha, D. S. Yufit, M. A. Kirpichenok, N. A. Gordeeva, Y. T. Struchkov, I. I. Grandberg

Indexed on: 01 Jan '91Published on: 01 Jan '91Published in: Chemistry of Heterocyclic Compounds



Abstract

The absorption and fluorescence spectra and the acid-base characteristics of 7-diethylaminocoumarins containing an aromatic substituent at position 3 and H, Cl, CH3,CF3,and N(CH2CH2)2O at position 4 were studied. For the para-substituted derivatives a linear correlation was obtained between the pKavalues and the Hammett σpconstants. On the basis of the obtained data, and also of an x-ray crystallographic investigation of 3-phenyl-4-methyl-7-diethylaminocoumarin it was concluded that there is weak π-πconjugation between the 3-aryl groups and the coumarin fragment.