Highly NIR-Emissive Lanthanide Polyselenides

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• 作者：Anna Kornienko ; Brian F. Moore ; G. Ajith Kumar ; Mei-Chee Tan ; Richard E. Riman ; Mikhail G. Brik ; Thomas J. Emge ; John G. Brennan
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：September 19, 2011
• 年：2011
• 卷：50
• 期：18
• 页码：9184-9190
• 全文大小：901K
• 年卷期：v.50,no.18(September 19, 2011)
• ISSN：1520-510X

文摘

Ln(SePh)₃ (Ln = Ce, Pr, Nd), prepared by reduction of PhSeSePh with elemental Ln and Hg catalyst, reacts with excess elemental Se to give (py)₁₁Ln₇Se₂₁HgSePh, an ellipsoidal polyselenide cluster. The molecular structure contains two square arrays of eight- or nine-coordinate Ln fused at one edge to form a V shape that is also capped on the concave side by a centrally located nine-coordinate (Se₃)pyLn(Se₃) and on the convex side by a 2-fold disordered SeHgSePh. The central Ln coordinates to selenido, triselenido, and pyridine ligands, while all other Ln coordinate to selenido, diselenido, triselenido, and pyridine ligands. Thermal treatment of the Pr compound at 650 掳C gave Pr₂Se₃ and Pr₃Se₄. NIR emission studies of the Nd compound show four transitions from the excited-state ⁴F_3/2 ion to ⁴I_9/2, ⁴I_11/2, ⁴I_13/2, and ⁴I_15/2 states. The ⁴F_3/2 ion to ⁴I_11/2 transition (1075 nm emission) exhibited 43% quantum efficiency. This is the highest quantum efficiency reported for a 鈥榤olecular鈥?Nd compound and leads a group of selenide-based clusters that has shown extraordinary quantum efficiency. In terms of efficiency and concentration, these compounds compare favorably with solid-state materials.