Mikhalova O. The influence of the structure of tris(pyrazolyl)borate and carboxylate complexes of lanthanides on their photo-, electro- and triboluminescent properties

The basic concepts of the influence of chemical, molecular, and crystal structure of coordination compounds of lanthanides (Ln3+) with different ligands on their luminescent and magnetic properties were developed. It was shown that luminescence quantum yields (QY) of Tb3+ complexes with tris(pyrazolyl)borates as antenna-ligands reached 80%, which is comparable to the highest values reported for lanthanide coordination compounds. It was found that the relative position of the ligands' energy levels in heteroligand Ln3+ complexes influence emission characteristics of such compounds. It was found that tris(pyrazolyl)borate complexes of Eu3+ and Tb3+ show intense metal-centered triboluminescence and complexes of Tb3+ also possess electroluminescence. Stacking interactions promoted excitation energy transfer over the distances up to 300 nm in TpPyGd(CH3CO2)2(H2O) doped with Eu3+ or Tb3+ ions, probably by a combination of electron-exchange and dipolar mechanisms. It was shown that, depending on the excitation wavelength, Pr3+ та Nd3+ compounds with tetrafluoroterephtalate or campharate dianions showed ligand-centered emission with inner-filter effects caused by absorption of Ln3+-ions or metal-centered emission.