N. Mateeva et al., SPECTROSCOPIC STUDY OF THE COMPLEXATION OF AN AZA-15-CROWN-5 CONTAINING CHROMOFLUOROIONOPHORE WITH BA2+ AND CA2+ CATIONS, Journal of inclusion phenomena and molecular recognition in chemistry, 20(4), 1994, pp. 323-333
The complexation of )phenyl]-4,7,10,13-tetraoxa-1-aza-cyclopentadecane
with Ba2+ and Ca2+ cations was investigated spectrophotometrically an
d spectrofluorometrically. The stability constants of the complexes fo
rmed are: for Ba2+ log K-st = 3.17 +/- 0.01 (absorption) and log K-st
= 2.95 +/- 0.03 (fluorescence); for Ca2+ log K-st = 3.71 +/- 0.02 (abs
orption) and log K-st = 3.58 +/- 0.05 (fluorescence). Protonation of t
he ligand leads to fluorescence quenching. AM1 and PPP quantum chemica
l calculations were used to predict molecular geometry, proton affinit
ies and the spectra of the compounds studied.