Peer-Reviewed Journal Details
Mandatory Fields
Maher, NJ;Diao, HW;O'Sullivan, J;Fadda, E;Heaney, F;McGinley, J
2015
December
Tetrahedron
Lower rim isoxazole-calix[4]arene derivatives as fluorescence sensors for copper(II) ions
Published
13 ()
Optional Fields
CATION-PI INTERACTION SELECTIVE RECOGNITION MOLECULAR RECOGNITION METAL COMPLEXATION CRYSTAL-STRUCTURES SOLID-STATE CU2+ CONJUGATE ZN2+ CHEMOSENSOR
71
9223
9233
Chemosensors designed around a calix[4]arene scaffold, possessing distal isoxazole nuclei as potential recognition sites in conjugation with fluorogenic reporting moieties, have been synthesised and their molecular structures determined by single crystal X-ray analysis. PIC (pyrene-isoxazole-calix[4]arene) and AIC (anthracene-isoxazole-calix[4]arene) are found to be selective and sensitive for the recognition of copper(II) ions over a range of divalent metal ions in a spectrofluorometric study in acetonitrile. Following exposure to copper(II) ions the fluorescence emission intensity of the host was dramatically quenched, in contrast there were no significant shifts to the UV-vis spectra. H-1 NMR spectroscopic studies could not provide unambiguous evidence for the mode of ion recognition. Hybrid Density Functional Theory (DFT) calculations for the PIC-copper(II) complex suggests that the metal ion adopts tetrahedral geometry in an acetonitrile solution, while a distorted square pyramidal coordination is also possible in the absence of solvent molecules. Both of these binding conformations cause the disruption of the pyrene-pyrene stacking, consistent with the observed fluorescence quenching. (C) 2015 Elsevier Ltd. All rights reserved.
OXFORD
0040-4020
10.1016/j.tet.2015.10.045
Grant Details