EMISSION OPTICAL ACTIVITY OF EUROPIUM(III) AND TERBIUM(III) COORDINATED TO CHRIAL CROWN ETHERS$^{\ast}$
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Date
1982
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Ohio State University
Abstract
Emission optical activity (EOA) is the emission analogue of circular dichroism (CD), and it probes similar aspects of molecular stereochemistry and electronic structure. Here we report the first observations of EOA for lanthanide ions coordinated to chiral crown ether ligands in solution media. Results are presented for Eu(III) and Tb(III) complexes of 2, 3, 11, 12-tetracarboxamide-18-crown-6(I) and 2, 6-dimethyl-15-crown-5(II) in a series of nonaqueous solvents. The emission optical activity spectra, as well as the unpolarized excitation and emission spectra, obtained on the complexes of I and II exhibit profound differences which can be interpreted in terms of differences in $Ln^{3+}$-ligand binding constants and differences in the stereochemical structures of the respective complexes, Pronounced solvent effects are also observed in the emission spectra of the two types of complexes.
Description
$^{\ast}$This work was supported by the National Science Foundation (NSF Grant CHE80-04209).