Eu(III) AND Tb(III) COMPLEXES BASED ON DIPHENYL(PYRIMIDIN-2-YL)PHOSPHINE OXIDE: SYNTHESIS, STRUCTURE, AND PHOTOLUMINESCENT PROPERTIES

Coordination compounds [Eu{Ph2P(O)Pym}2(NO3)3] (1) and [Tb{Ph2P(O)Pym}2(MeOH)(NO3)3] (2) are synthesized by the interaction of Eu(III) and Tb(III) nitrates with diphenyl(pyrimidin-2-yl)phosphine oxide (Ph2P(O)Pym). According to single crystal XRD data, the crystal structures of 1 and 2 consist of molecules of mononuclear complexes. The Ph2P(O)Pym ligand is bidentate chelating and monodentate in complexes 1 and 2 respectively; coordination polyhedra of the Ln atom are N2O8 in 1 and O9 in 2. The presence of C–H⋯O hydrogen bonds between the neighboring molecules of the complexes leads to the formation of dimeric ensembles organized in chains (in 1) and layers (in 2) by weaker hydrogen bonds. The complexes exhibit metal-centered photoluminescence in the solid state at 300 K with long lifetimes of excited states (τ > 1 ms) and luminescence quantum yields φ = 28% and 14% for complexes 1 and 2 respectively.