Homotrinuclear Lanthanide(III) Arrays: Assembly of and Conversion from Mononuclear and Dinuclear Units
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- 作者：Ika A. Setyawati ; Shuang Liu ; Steven J. Rettig ; and Chris Orvig
- 刊名：Inorganic Chemistry
- 出版年：2000
- 出版时间：February 7, 2000
- 年：2000
- 卷：39
- 期：3
- 页码：496 - 507
- 全文大小：239K
- 年卷期：v.39,no.3(February 7, 2000)
- ISSN：1520-510X
文摘
The reactions of potentially hexadentate H2bbpen (N,N '-bis(2-hydroxybenzyl)-N,N '-bis(2-pyridylmethyl)ethylenediamine, H2L1), H2(Cl)bbpen (N,N '-bis(5-chloro-2-hydroxybenzyl)-N,N '-bis(2-pyridylmethyl)ethylenediamine, H2L2), and H2(Br)bbpen (N,N '-bis(5-bromo-2-hydroxybenzyl)-N,N '-bis(2-pyridylmethyl)ethylenediamine,H2L3) with Ln(III) ions in the presence of a base in methanol resulted in three types of complexes: neutralmononuclear ([LnL(NO3)]), monocationic dinuclear ([Ln2L2(NO3)]+), and monocationic trinuclear ([Ln3L2(X)n(CH3OH)]+), where X = bridging (CH3COO-) and bidentate ligands (NO3-, CH3COO-, ClO4-) and n is 4. Theformation of a complex depends on the base (hydroxide or acetate) and the size of the respective Ln(III) ion. Allcomplexes were characterized by infrared spectroscopy, mass spectrometry, and elemental analyses; in somecases, X-ray diffraction studies were also performed. The structures of the neutral mononuclear [Yb(L1)(NO3)],dinuclear [Pr2(L1)2(NO3)(H2O)]NO3·CH3OH and [Gd2(L1)2(NO3)]NO3·CH3OH·3H2O, and trinuclear [Gd3(L3)2(CH3COO)4(CH3OH)]ClO4·5CH3OH and [Sm3(L1)2(CH3COO)2(NO3)2(CH3OH)]NO3·CH3OH·3.65H2O were solvedby X-ray crystallography. The [LnL(NO3)] or [Ln2L2(NO3)]+ complexes could be converted to [Ln3L2(X)n(CH3OH)]+ complexes by the addition of 1 equiv of a Ln(III) salt and 2-3 equiv of sodium acetate in methanol. Thetrinuclear complexes were found to be the most stable of the three types, which was evident from the presenceof the intact monocationic high molecular weight parent peaks ([Ln3L2(X)n]+) in the mass spectra of all thetrinuclear complexes and from the ease of conversion from the mononuclear or dinuclear to the trinuclear species.The incompatibility of the ligand denticity with the coordination requirements of the Ln(III) ions was proven tobe a useful tool in the construction of multinuclear Ln(III) metal ion arrays.