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Information × Registration Number 0219U000160, 0117U004548 , R & D reports Title The development of new high luminescent systems based on lanthanide complexes and hybrid nanocomposites for the needs of modern nanoelectronics popup.stage_title Head Pavlishchuk Vitaliy Valentinovich, Registration Date 17-01-2019 Organization Institute of Physical Chemistry L.V.Pisarzhevsky NAS Ukraine popup.description2 As a result of the project in 2018 a series of binuclear complexes of lanthanides (Tp2Ln)2L and Ln2L3 (Ln = Eu, Tb, Gd, Dy; Tp- = tris(pyrazolyl)borate, L2 = 4,4'-bis(2-sulfonato-styryl) biphenyl), and two types of mixtures of complexes (Tp2Eu)2C2O4 with (Tp2Ln)2C2O4 (Ln = Tb, Gd) and (TpPyEu)2pma with (TpPyLn)2pma (Ln = Tb, Gd; TpPy- = Tris (2-pyridylpyrazolyl)borate, pma4- = tetraanion 1,2,4,5-benzenetetracarboxylic acid) with a ratio of (Tp2Eu)2C2O4 to (Tp2Ln)2C2O4 (Ln = Tb, Gd) and (TpPyEu)2pma to (TpPyLn )2pma (Ln = Tb, Gd) 0.0, 0.1, 0.5, 0.9, 1.0, obtained by recrystallization of the compounds from the solution or by mechanical grinding of the prepared binuclear complexes in appropriate proportions. It was found that in the luminescence spectra of mixtures of the complexes Eu3 + and Tb3 +, the characteristic emission of both of these ions appeared, which allows to change the color of the luminescence in the line red (Eu3 +) - yellow (Eu3 ++ Tb3 +) - green (Tb3 +) by varying the ratio of metals. It was found that in the mixture of polynuclear complexes (Tp2Eu)2C2O4 and (Tp2Ln)2C2O4 (Ln = Tb, Gd) and (TpPyEu)2pma and (TpPyLn)2pma (Ln = Tb, Gd) of different composition obtained by crystallization of solutions of complexes the more effective Eu3 + emission sensitization observed compared to mixtures of the same compounds obtained by grinding of the corresponding quantities of the prepared binuclear complexes. This indicates that a more regular distribution of lanthanide ions promotes a more efficient energy transfer to the level of Eu3 + ions in the first case. Although the emission of the compounds (Tp2Ln)2L and Ln2L3 (Ln = Gd3 +, Tb3 + and Dy3 +) is due to fluorescence L2-, it was shown that the color of the radiation varies from blue-violet to green depending on the composition of the complex, which may be due to a significant change in the electronic structure of this anion in the indicated compounds. It was also found that in the case of the complexes (Tp2Eu)2L and Eu2L3, the emission of L2- is generally absent, which is probably caused by luminescence quenching due to energy migration processes between the levels of this anion and the Eu3 + ion, since such processes increase the efficiency of non-radiation deactivation of excited states. At the same time, the complex (Tp2Eu)2L shows Eu3 + -centered emission in phosphorescence spectrum, which may be due to the presence of Tris(pyrazolyl)borate anion whis is an effective ligand-antenna for the Eu3 + ion. So, depending on the composition of the complexes with L2- the color of the emission can vary from blue-violet to red. Product Description popup.authors Василенко І.В. Міхальова О.А. Павліщук В.В. popup.nrat_date 2020-04-02 Close