Lanthanide Clusters with Chalcogen Encapsulated Ln: NIR Emission from Nanoscale NdSex

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• 作者：Brian F. Moore ; G. Ajith Kumar ; Mei-Chee Tan ; Jesse Kohl ; Richard E. Riman ; Mikhail G. Brik ; Thomas J. Emge ; John G. Brennan
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：January 19, 2011
• 年：2011
• 卷：133
• 期：2
• 页码：373-378
• 全文大小：259K
• 年卷期：v.133,no.2(January 19, 2011)
• ISSN：1520-5126

文摘

Ln(SePh)₃ (Ln = Ce, Pr, Nd) reacts with elemental Se in the presence of Na ions to give (py)₁₆Ln₁₇NaSe₁₈(SePh)₁₆, a spherical cluster with a 1 nm diameter. All three rare-earth metals form isostructural products. The molecular structure contains a central Ln ion surrounded by eight five-coordinate Se^{2鈭?/sup> that are then surrounded by a group of 16 Ln that define the cluster surface, with additional 渭₃ and 渭₅ Se2鈭?/sup>, 渭₃ and 渭₄ SePh鈭?/sup>, and pyridine donors saturating the vacant coordination sites of the surface Ln, and a Na ion coordinating to selenolates, a selenido, and pyridine ligands. NIR emission studies of the Nd compound reveal that this material has a 35% quantum efficiency, with 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 clearly evident. The presence of Na+ is key to the formation of these larger clusters, where reactions using identical concentrations of Nd(SePh)₃ and Se with either Li or K led only to the isolation of (py)₈Nd₈Se₆(SePh)₁₂.}