Cationic Assembly of Metal Complex Aggregates: Structural Diversity, Solution Stability, and Magnetic Properties
详细信息 查看全文
- 作者：Xiang Lin ; Dan M. J. Doble ; Alexander J. Blake ; Andrew Harrison ; Claire Wilson ; and Martin Schrö ; der
- 刊名：Journal of the American Chemical Society
- 出版年：2003
- 出版时间：August 6, 2003
- 年：2003
- 卷：125
- 期：31
- 页码：9476 - 9483
- 全文大小：427K
- 年卷期：v.125,no.31(August 6, 2003)
- ISSN：1520-5126
文摘
The tetradentate imino-carboxylate ligand [L]2- chelates the equatorial sites of NiII to give thecomplex [Ni(L)(MeOH)2] in which a NiII center is bound in an octahedral coordination environment withMeOH ligands occupying the axial sites. Lanthanide (Ln) and Group II metal ions (M) template theaggregation of six [Ni(L)] fragments into the octahedral cage aggregates {M[Ni(L)]6}x+ (1: M = SrII; x = 2,2: M = BaII; x = 2, 3: M = LaIII; x = 3, 4: M = CeIII; x = 3, 5: M = PrIII; x = 3, and 6: M = NdIII; x = 3).In the presence of Group I cations, however, aggregates composed of the alkali metal-oxide cations templatevarious cage compounds. Thus, Na+ forms the trigonal bipyramidal [Na5O]3+ core within a tricapped trigonalprismatic [Ni(L)]9 aggregate to give {(Na5O)
[Ni(L)]9(MeOH)3}(BF4)2·OH·CH3OH, 7. Li+ and Na+ togetherform a mixed Li+/Na+ core comprising distorted trigonal bipyramidal [Na3Li2O]3+ within an approximatelyanti-square prismatic [Ni(L)]8 cage in {(Na3Li2O)[Ni(L)]8(CH3OH)1.3(BF4)0.7}(BF4)2.3·(CH3OH)2.75·(C4H10O)0.5,8, while in the presence of Li+, a tetrahedral [Li4O]2+ core within a hexanuclear open cage [Ni(L)]6 in{(Li4O)[Ni(L)]6(CH3OH)3}2ClO4·1.85CH3OH, 9, is produced. In the presence of H2O, the Cs+ cation inducesthe aggregation of the [Ni(L)(H2O)2] monomer to give the cluster Cs2[Ni(L)(H2O)2]6·2I·4CH3OH·5.25H2O,10. Analysis by electronic spectroscopy and mass spectrometry indicates that in solution the trend in stabilityfollows the order 1-6 > 7 > 8 ~ 9. Magnetic susceptibility data indicate that there is net antiferromagneticexchange between magnetic centers within the cages.
[Ni(L)]9(MeOH)3}(BF4)2·OH·CH3OH, 7. Li+ and Na+ togetherform a mixed Li+/Na+ core comprising distorted trigonal bipyramidal [Na3Li2O]3+ within an approximatelyanti-square prismatic [Ni(L)]8 cage in {(Na3Li2O)[Ni(L)]8(CH3OH)1.3(BF4)0.7}(BF4)2.3·(CH3OH)2.75·(C4H10O)0.5,8, while in the presence of Li+, a tetrahedral [Li4O]2+ core within a hexanuclear open cage [Ni(L)]6 in{(Li4O)[Ni(L)]6(CH3OH)3}2ClO4·1.85CH3OH, 9, is produced. In the presence of H2O, the Cs+ cation inducesthe aggregation of the [Ni(L)(H2O)2] monomer to give the cluster Cs2[Ni(L)(H2O)2]6·2I·4CH3OH·5.25H2O,10. Analysis by electronic spectroscopy and mass spectrometry indicates that in solution the trend in stabilityfollows the order 1-6 > 7 > 8 ~ 9. Magnetic susceptibility data indicate that there is net antiferromagneticexchange between magnetic centers within the cages.