ИСТИНА

Lanthanide containing metal organic frameworks (Ln-MOFs) are in the focus of attention of researchers due to the unique combination of sorption and luminescence properties, promising for chemical sensing tasks. Sensory material must meet a number of requirements - high stability, low solubility, the minimum amount of CH,NH and OH quenchers. Triazole-dicarboxylic acid (H3TDA) based Ln-MOFs meet all these criteria. The intensity ratio of the radiative transitions of terbium (5D4-7F5) and europium (5D0-7F2) was chosen as the analytical signal (S). Depending on the conditions of solvothermal synthesis, two types of complex 1,2,3-triazole-4,5-dicarboxylates of lanthanides can be obtained, namely {[Ln(TDA)(H2O)2](H2O)3} and {(NMe2H2)[Ln(TDA)(HCOO)]}, Ln = Eu, Tb, Gd. A series of both types of complexes containing various amounts of terbium and europium was synthesized. It was shown that in such systems the excitation energy is transferred along the pathway ligandTb3+Eu3+. The compounds were tested as sensor materials for the determination of water traces in aprotic organic solvents and D2O. In addition, they show sensory activity for transition metal cations - Zn2+ and Co2+. Figure 1. Calibration charts for the H2O-D2O (red squares), H2O-dioxane (green circles) and H2O-CH3CN (blue triangles) systems. Acknowledgements - we are grateful to the RFBR project number 19-03-00263А. Synthetic part of the research was supported by the Russian Science Foundation (grant No. 19-13-00272).