Syntheses, Structure, and Luminescent Properties of Novel Hydrated Rare Earth Borates Ln2B6O10(OH)4鈥2O (Ln = Pr, Nd, Sm, Eu, Gd, D

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• 作者：Rihong Cong ; Tao Yang ; Zheming Wang ; Junliang Sun ; Fuhui Liao ; Yingxia Wang ; Jianhua Lin
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：March 7, 2011
• 年：2011
• 卷：50
• 期：5
• 页码：1767-1774
• 全文大小：1007K
• 年卷期：v.50,no.5(March 7, 2011)
• ISSN：1520-510X

文摘

Ln₂B₆O₁₀(OH)₄鈥₂O (Ln = Pr, Nd, Sm鈭扜d, Dy, Ho, and Y), a new series of hydrated rare earth borates, have been synthesized under hydrothermal conditions. A single crystal of Nd analogue was used for the structure determination by X-ray diffraction. It crystallizes in the monoclinic space group C2/c with lattice constants a = 21.756(4), b = 4.3671(9), c = 12.192(2) 脜, and 尾 = 108.29(3)掳. The other compounds are isostructural to Nd₂B₆O₁₀(OH)₄鈥₂O. The fundamental building block (FBB) of the polyborate anion in this structure is a three-membered ring [B₃O₆(OH)₂]^{5鈭?/sup>. The FBBs are connected by sharing oxygen atoms forming an infinite [B₃O₅(OH)₂]3鈭?/sup> chain, and the chains are linked by hydrogen bonds, establishing a two-dimensional (2-D) [B₆O₁₀(OH)₄鈥₂O]6鈭?/sup> layer. The 2-D borate layers are thus interconnected by Ln3+ ions to form the complex three-dimensional structure. Ln₂B₆O₁₀(OH)₄鈥₂O dehydrates stepwise, giving rise to two new intermediate compounds Ln₂B₆O₁₀(OH)₄ and Ln₂B₆O₁₁(OH)₂. The investigation on the luminescent properties of Gd_2鈭?xEu_2xB₆O₁₀(OH)₄鈥₂O (x = 0.01鈭?.00) shows a high efficiency of Eu3+ f鈭抐 transitions and the existence of the energy transfer process from Gd3+ to Eu3+. Eu₂B₆O₁₀(OH)₄鈥₂O and its two dehydrated products, Eu₂B₆O₁₀(OH)₄ and Eu₂B₆O₁₁(OH)₂, present the strongest emission peak at 620 nm (5D₀ 鈫?7F₂ transition), which may be potential red phosphors.}