Effect of host–guest complex formation on the fluorescence of 6-methoxy-1-methyl-quinolinium cation with 4-sulfonatocalix[4]arene: utilization as a fluorescent probe for the study of difenzoquat binding

The complexation of the highly fluorescent 6-methoxy-1-methyl-quinolinium (C 1 MQ) and the widely used herbicide, difenzoquat (DFQ), with 4-sulfonatocalix[4]arene (SCX4) macrocycle was studied by isothermal titration calorimetry, fluorescence and NMR spectroscopy in aqueous solutions at 298 K. Both...

Full description

Saved in:
Bibliographic Details
Published in:Journal of inclusion phenomena and macrocyclic chemistry 2015-04, Vol.81 (3-4), p.377-384
Main Authors: Harangozó, József G., Miskolczy, Zsombor, Biczók, László, Wintgens, Véronique, Lorthioir, Cédric
Format: Article
Language:English
Subjects:
Chemistry
Chemistry and Materials Science
Crystallography and Scattering Methods
Food Science
Organic Chemistry
Original Article
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The complexation of the highly fluorescent 6-methoxy-1-methyl-quinolinium (C 1 MQ) and the widely used herbicide, difenzoquat (DFQ), with 4-sulfonatocalix[4]arene (SCX4) macrocycle was studied by isothermal titration calorimetry, fluorescence and NMR spectroscopy in aqueous solutions at 298 K. Both guests produced 1:1 complexes with SCX4, but the binding affinity of C 1 MQ was more than one order of magnitude larger than that of DFQ in neutral medium. The higher stability of C 1 MQ-SCX4 complex originated from the significant enthalpy gain upon its formation. The encapsulation of C 1 MQ in SCX4 in the ground state resulted in an efficient fluorescence quenching due to electron transfer from the host to the excited guest. The marked difference in the fluorescence quantum yields for free and bound C 1 MQ was used to detect the competitive complexation of DFQ in SCX4.
ISSN:1388-3127
1573-1111
DOI:10.1007/s10847-014-0464-9