A substituted pyridazine was used to construct a family of mononuclear heteroleptic complexes [Ln(tta)₃(dppn)], Ln = Pr–Lu; Htta = thenoyltrifluoroacetone; dppn = 3,6-di(2-pyridyl)pyridazine. All the complexes obtained were characterized by CHN elemental analysis, NMR spectroscopy, ESI mass spectrometry, FTIR spectroscopy and single crystal X-ray analysis. The photophysical properties of lanthanide complexes were carefully investigated, and the dppn ligand was found to act as a chromophore centre to sensitize metal-centred emission of the Nd, Sm, Eu, and Yb complexes under UV excitation. It has been shown that a powder sample of the Eu complex can contain two isomers with somewhat different symmetries of the environment of the metallocentre. The mechanism for the emission of luminescent Nd, Sm, Eu, and Yb complexes was investigated by TDDFT calculations and the results confirmed the conclusion made on the basis of experimental data regarding the likely pathway of energy transfer from the chromophore centre to the emissive level of Ln(III).

中文翻译：

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用吡啶基取代的哒嗪配体 修饰的β-二酮丙酮酸Ln（iii）配合物：合成，结构和发光性能†

用取代的哒嗪构建了一个单核杂配物[Ln（tta）₃（dppn）]，Ln = Pr–Lu； Ln = Pr–Lu。H tta =壬基三氟丙酮；dppn＝ 3，6-二（2-吡啶基）哒嗪。通过CHN元素分析，NMR光谱，ESI质谱，FTIR光谱和单晶X射线分析对所有获得的配合物进行表征。仔细研究了镧系元素配合物的光物理性质，并研究了dppn发现配体充当发色团中心，以在紫外线激发下敏化Nd，Sm，Eu和Yb络合物的金属中心发射。已经表明，Eu络合物的粉末样品可以包含两种异构体，其金属中心环境的对称性略有不同。通过TDDFT计算研究了发光Nd，Sm，Eu和Yb配合物的发射机理，该结果证实了基于实验数据得出的结论，该结论是能量从生色团中心转移到发光级的可能途径。 Ln（III）。