Characterization of the coordination between Nd3+ and ester groups by using double asynchronous orthogonal sample design approach

We applied a newly developed technique of DAOSD (double asynchronous orthogonal sample design) approach to probe weak coordination between Nd3+ ions and ethyl acetate. Cross peaks from the 2D asynchronous spectra are successfully used to reveal subtle spectral variation on carbonyl band of ethyl acetate and f–f transition peak of Nd3+, which is relevant to the coordination between Nd3+ and the ester group of ethyl acetate. In addition, we also use 13C NMR spectra to investigate the Nd3+/ethyl acetate system. The appearance of new weak carbonyl peak around 177.8 ppm provides alternative evidence of the weak coordination between Nd3+ and ester group of ethyl acetate.