Coordination compounds of neodymium, samarium, and europium with acyldihydrazones of imino-, oxo-, and thiodiacetic acids and 3-methyl-1-phenyl-4-formylpyrazol-5-one

The coordination compounds of neodymium(III), samarium(III), and europium(III) with the acyldihydrazones of imino-, oxo-, and thiodiacetic acids and 3-methyl-1-phenyl-4-formylpyrazol-5-one were synthesized and studied. According to X-ray diffraction data, the complexes are binuclear and the lanthanide cations are linked by three binucleating ligands. The coordination polyhedra have a three-cap triangular prism geometry, the prism bases being formed by oxygen atoms and the vertices being occupied by the imine nitrogen atoms. Solid Nd(III) and Sm(III) complexes show intense luminescence in the spectral regions characteristic of these cations. Europium(III) complexes are liminescence-inactive due to the low efficiency of excitation energy transfer to the resonance levels of the central atom.