Guanidinium as powerful cation for the design of lanthanate tris-dipicolinate crystalline materials: Synthesis, structure and photophysical properties

This article reports the synthesis, the structures and the photophysical properties of various lanthanate tris-dipicolinate complexes featuring guanidinium (Gua) as counter-cation (Ln = La, Ce, Eu, Tb, Dy, Tm). The X-rays crystal structure of [Gua]3[Ce(DPA)3] · 3H2O is described and compared to that of [Na]3[Ce(DPA)3] · 14H2O. The particular case of Cerium, the only yellow complex, is studied by absorption spectroscopy and cyclic voltammetry, and finally the emission properties of lanthanides complexes emitting in the visible spectral range (Eu, Tb, Dy, Tm) are studied in solution as in crystalline materials.