Solution, Solid State, and Film Properties of a Structurally Characterized Highly Luminescent Molecular Europium Plastic Material Excitable with Visible Light

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• 作者：Gae虉l Zucchi ; Vajjiravel Murugesan ; Denis Tondelier ; Dmitry Aldakov ; Taewoo Jeon ; Feng Yang ; Pierre Thue虂ry ; Michel Ephritikhine ; Bernard Geffroy
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：June 6, 2011
• 年：2011
• 卷：50
• 期：11
• 页码：4851-4856
• 全文大小：820K
• 年卷期：v.50,no.11(June 6, 2011)
• ISSN：1520-510X

文摘

The synthesis and X-ray crystal structure of the ligand L (4,7-dicarbazol-9-yl-[1,10]-phenanthroline) are reported, as well as those of the molecular complex, [Eu(tta)₃(L)] (1), (tta = 2-thenoyl trifluoroacetylacetonate). Their photophysical properties have been investigated both in solution and in the solid state. It was shown that the ligands used for designing 1 are well-suited for sensitizing the Eu^III ion emission, thanks to a favorable position of the triplet state as investigated in the Gd^III complex [Gd(tta)₃(L)], (2). The low local symmetry of the Eu^III ion shown by the X-ray crystal structure of 1 is also revealed by luminescence spectroscopy. Because of interesting volatility and solubility properties, 1 is shown to behave as a real molecular material that can be processed both by thermal evaporation and from solution. When doped in poly(methylmethacrylate) (PMMA), 1 forms air-stable and highly red-emitting plastic materials that can be excited in a wide range of wavelengths from the UV to the visible part of the electromagnetic spectrum (250鈥?60 nm). Absolute quantum yields of 80% have been obtained for films comprising 1鈥?% of 1. Ellipsometry measurements have been introduced to gain information on physical data of 1. They have been performed on thin films of 1 deposited by thermal evaporation and gave access to the refractive index, n, and the absorption coefficient, k, as a function of the wavelength. A value of 1.70 has been found for n at 633 nm. These thin films also show interesting air-stability.