Synthesis, crystal structure and photophysical properties of a neodymium trifluoroacetate complex with 2,2'-bipyridine

The neodymium trifluoroacetate complexes were synthesized and characterized by single-crystal X-ray diffraction for [Nd(CF3COO)3·Bpy·(H2O)3]Bpy (1), elemental and TG analysis, FT-IR spectra, and PL spectra for Nd(CF3COO)3·Bpy (2) (Bpy: 2,2'-bipyridine). The most interesting feature of the crystal structure for 1 is that it comprises a coordinated 2,2'-bipyridine molecule and an out-sphere 2,2'-bipyridine molecule. At the same time, the C-O distances appeared average which indicates the three atoms of carboxylato forming electron-conjugate system. Hydrogen bond and p-p-stacking link the binuclear to two-dimensional sheet. The optical spectra for 2 exhibited that the complex possessed typical Nd (III) ion absorption and photoluminescence emission. The emission cross-section of 4F3/2→4I11/2 fluorescence transition (3.63×10−20 cm2) was comparable with some laser glasses, which indicated good radiative properties of this neodymium trifluoroacetate complex in liquid matrix. The thermal analysis indicated that it was quite stable to heat.