Abstract

In the past, magnetic resonance imaging (RMI) has become an ever popular diagnosis method in medicine. The use of increased relaxation rates of protons in water has significantly improved the quality of the image. An example of this type of contrast agents are the compounds formed by Gd(III) with DOTA or DPTA ligands, which contain carboxyl groups, that can be prepared from ligands with dioxolane groups. These agents must have a high effective magnetic momento and for this reason Gd(III) is chosen to coordinate these ligands [1], [2].

 From macrocycles with secondary amino groups in trans positions, tetra- or di- substituted compounds were obtained by direct reaction with dioxolane groups [3], which can be separated by recrystallization for further study as lanthanide ion receptors.

References

[1] Q. Zheng, H. Dai, M. E. Merritt, C. Malloy, C. Y. Pan, W. Li, J. Am. Chem. Soc., 2005, 127, 16178.

[2]  M. K. Moi, C. F. Meares, S. J. De Nardo, J. Am. Chem. Soc., 1988, 110(18), 6266.

[3] C. Núñez, R. Bastida, A. Macías, A. Aldrey, L. Valencia, Polyhedron, 2010, 29(1), 126.

Acknowledgements

This work was made possible thanks to the financial support received from the Xunta de Galica (Galicia, Spain) under the Grupos de Referencia Competitiva Programme (Project GRC2015/009). F.L.−M. thanks the Spanish Ministry of Education (grant FPU13/05014).