Z/E (C=C)-isomerization and fluorescence modulation of imines of 7-N,N-dialkylamino-4-hydroxy-3-formylcoumarins in organic solvents

[摘要] Imines of 7-dialkylamino-3-formyl-4-hydroxycoumarins have been found to exist in Z -ketoenamine form in crystal state and undergo Z/E -isomerization around C=C bond in organic solvents at room temperature. Activation energies of isomerization have been measured experimentally and calculated by the DFT B3LYP method. Transition of ketoenamine form of p -nitrophenylimines into (hydroxy)imine form at low concentration (10 -5   m ) in polar solvents is accompanied by strong increase in fluorescence.

[学科分类] 内科医学

[关键词] coumarin;fluorescence;imines;isomerization;solvents