Long-range magnetic coupling through extended pi-conjugated aromatic bridges in dinuclear copper(II) metallacyclophanes.
Long-range magnetic coupling through extended pi-conjugated aromatic bridges in dinuclear copper(II) metallacyclophanes.
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DOI：
10.1021/ja030060f
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发表时间：
2003-08
影响因子：
15
通讯作者：
E. Pardo;J. Faus;M. Julve;F. Lloret;M. C. Muñoz;J. Cano;X. Ottenwaelder;Y. Journaux;R. Carrasco;G. Blay;I. Fernández;Rafael Ruiz-García
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文献类型：
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作者：
E. Pardo;J. Faus;M. Julve;F. Lloret;M. C. Muñoz;J. Cano;X. Ottenwaelder;Y. Journaux;R. Carrasco;G. Blay;I. Fernández;Rafael Ruiz-García
1,4-苯乙烯双（草酸酯）和4,4'-联苯双（草酸酯）配体与Cu2+离子的自组装产生了两个新的双核铜（II）金属环烷，其中两个金属中心由双对取代芳香二胺桥连接。尽管每个络合物的分子内Cu-Cu距离相对较大，约为8 A和12 A，但磁化率测量表明，分子内反铁磁耦合强至中等强（-J值分别为100和10 cm-1）。对这些化合物及其具有线性低聚对苯二胺桥的同系物的密度泛函理论计算预测，沿着这种新型金属二铜-氨基环烷系列，随着金属间距离（r值高达25 a）的增加，磁偶联的指数衰减相当缓慢。
Self-assembly of 1,4-phenylenebis(oxamate) and 4,4'-biphenylenebis(oxamate) ligands and Cu2+ ions gives two new dinuclear copper(II) metallacyclophanes where the two metal centers are connected by double para-substituted aromatic diamide bridges. Despite the relatively large intramolecular Cu-Cu distance of ca. 8 and 12 A for each complex, magnetic susceptibility measurements evidence strong to moderately strong intramolecular antiferromagnetic couplings (-J values of the order of 100 and 10 cm-1, respectively). Density functional theory calculations on these compounds and their homologues with linear oligo-p-phenylenediamide bridges predict a rather slow exponential decay of magnetic coupling with increasing intermetal distance (r values up to 25 A) along this novel series of dicopper metalla-amidocyclophanes.