The synthesis of novel macrocycles, Part V. The coumarin crown ethers and cation binding with fluorescence spectra

The 4-H, 4-methyl and g-phenyl derivatives of benzo-alpha-pyrone of 12-crow n-4 and 15-crown-5 were synthesised starting from 4-substituted-6,7-dihydro xy- and 7,8-dihydroxybenzo-alpha-pyrones which reacted with dichloropolyeth ylene glycols in DMF/water/alkali carbonate. The coumarin-macrocycles were identified by elemental analysis, IR, EI-GC-MS as well as H-1, C-13 NMR spe ctroscopy. The full experimental and spectral data is reported along with i on binding data studied in acetonitrile using fluorescence spectroscopy. Th e binding of the fluorogenic coumarin-crowns with Li+, Na+ and K+ were reco gnized as specific alterations on their fluorescence spectra that strongly originated from the structures. The observed CEQFS depending on the bound c ation radii and macrocycle size evidenced the rules of cationic recognition of macrocycles. Some 15-crown-5 derivatives exhibited interesting Li+ and Nat binding selectivities.