Experimental assessment of lanthanide ion donor preference: spectroscopic and theoretical dissection of static charge and dynamic polarisation contributions to axial ligation in a C4-symmetric chiral europium complexElectronic supplementary information available (ESI) space filling images of [Eu1·H2O], Tables and plots of selected 1H NMR data, emission spectra for [Eu.1]3+ and examples of least-squares fitting analysis for selected binding isotherms. See http://www.rsc.org/suppdata/cc/b1/b105006k/

Abstract

Measurements of the equilibrium constants for ligand exchange (MeCN, 295 K) involving the axial donor in a C₄-symmetric, mono-capped, square antiprismatic cationic Eu complex, supported by calculations based on an electrostatic perturbation model, have been interpreted in terms of a predominant ligand polarisation interaction defined by observation of the hypersensitive ΔJ = 2 normalised emission intensity, in association with measurements correlating ΔJ = 1 band splitting and ¹H NMR dipolar shifts that vindicate Bleaney’s theory of magnetic anisotropy.