Complexation properties of anthracene-bridged bis-crown ethers

Citation
R. Ostaszewski et al., Complexation properties of anthracene-bridged bis-crown ethers, J CHEM S P2, (6), 1999, pp. 1193-1198
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
ISSN journal
0300-9580 → ACNP
Issue
6
Year of publication
1999
Pages
1193 - 1198
Database
ISI
SICI code
0300-9580(199906):6<1193:CPOABE>2.0.ZU;2-O
Abstract
The complexation properties of new hosts consisting of two crown ethers con nected by an anthracene group have been studied using spectrophotometry, fl uorescence spectroscopy and cyclic voltammetry. The complexation and recogn ition properties of these ligands depend significantly on alkyl substituent s at the 9- and 10-position of the anthracene group and are also strongly i nfluenced by the solvent. The highest complexation constants with sodium an d thallium cations in dimethylformamide were found for ligands with heptyl and ethyl groups. From spectrophotometric titration data it is evident that both crown ether rings participate in formation of complexes with; sodium and potassium cations in chloroform-methanol. The determined complexation c onstants show a negative cooperation effect because K-M2L/K-ML < 0.25. The results of fluorescence experiments with the ligand substituted with two et hyl groups show a decrease in ligand fluorescence upon potassium cation add ition, which excludes the formation of sandwich complexes, and suggests tha t these ligands might be suitable for fluorescence potassium sensors.