Pereira, V. M. Costa, A. L. Feldl, J. Maria, T. M. R. Seixas, de Melo Martín-Ramos, P. Martín-Gil, J. Ramos Silva, M. Synthesis, structure and physical properties of luminescent Pr(III) ß-diketonate complexes Spectrochim. acta, Part A: Mol. biomol. spectrosc. 10.1016/j.saa.2016.06.025 2017 2017