Anion-Induced Self-Assembly of Luminescent and Magnetic Homoleptic Cyclic Tetranuclear Ln4(Salen)4 and Ln4(Salen)2 Complexes (Ln = Nd, Yb, Er, or Gd)

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• 作者：Weixu Feng ; Yao Zhang ; Zhao Zhang ; Xingqiang L眉 ; Han Liu ; Guoxiang Shi ; Dan Zou ; Jirong Song ; Daidi Fan ; Wai-Kwok Wong ; Richard A. Jones
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：November 5, 2012
• 年：2012
• 卷：51
• 期：21
• 页码：11377-11386
• 全文大小：505K
• 年卷期：v.51,no.21(November 5, 2012)
• ISSN：1520-510X

文摘

Unique homoleptic cyclic tetranuclear Ln₄(Salen)₄ complexes [Ln₄(L)₂(HL)₂(渭₃-OH)₂Cl₂]路2Cl (Ln = Nd, 1; Ln = Yb, 2; Ln = Er, 3; Ln = Gd, 4) or Ln₄(Salen)₂ complexes [Ln₄(L)₂(渭₃-OH)₂(OAc)₆] (Ln = Nd, 5; Ln = Yb, 6; Ln = Er, 7; Ln = Gd, 8) have been self-assembled from the reaction of the hexadentate Salen-type Schiff-base ligand H₂L with LnCl₃路6H₂O or Ln(OAc)₆路6H₂O (Ln = Nd, Yb, Er, or Gd), respectively (H₂L: N,N鈥?bis(salicylidene)cyclohexane-1,2-diamine). The result of their photophysical properties shows that the strong and characteristic NIR luminescence for complexes 1鈥?b>2 and 5鈥?b>6 with emissive lifetimes in microsecond ranges are observed, and the sensitization arises from the excited state (both ¹LC and ³LC) of the hexadentate Salen-type Schiff-base ligand with the flexible linker. Temperature dependence (1.8鈥?00 K) magnetic susceptibility studies of the eight complexes suggest the presence of an antiferromagnetic interaction between the Ln³⁺ ions.