修飾不對稱萘啶吡啶二胺配基(H2npts)及其五核金屬串錯合物之合成與研究

Synthesis and Studies of Pentanuclear Metal Complexes with the Modified Unsymmetrical H2npts Ligand

莊靜宜(Ching-Yi Chuang)

指導教授 ： 彭旭明

國立臺灣大學/理學院/化學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.02741

摘要

本論文的研究主要是根據配基微調的概念，將萘啶與傳統的多吡啶胺系統結合，並且導入具有立體障礙的磺醯基團，合成出不對稱的配基H2npts，並將此配基H2npts進一步合成為新型的五核鎳金屬串錯合物。
此不對稱配基是經由鈀金屬鹽類催化反應得到1，並由1H-NMR和ESI-Mass鑑定其結構和純度。利用配基H2npts在高溫萘燒的反應條件下，可以得到新型的五核鎳金屬串錯合錯[Ni5(npts)4]。由X-ray單晶繞射分析，其結構為(2,2)-trans form，且不具有軸向配基，所以，五個鎳金屬都為平面四邊形的配位環境。由磁性的量測，證實五核鎳金屬串錯合物[Ni5(npts)4]的兩個末端具有[Ni2]3+單元，是因為萘啶系統可以穩定低氧化態的鎳金屬，形成(Ni2)3+-Ni2+-(Ni2)3+。將磁性進行擬合，得到兩個末端的[Ni2]3+單元之間有反鐵磁作用，J = -54.46 cm-1。與過去所合成的萘啶系統相比較，當[Ni2]3+單元之間的距離增加，兩者之間的反鐵力作用力會變小，符合磁性和電化學上所得之結果。
根據電化學的分析，錯合物[Ni5(npts)4]具有三個可逆的氧化還原對，可知其為易氧化的物種，因此未來可利用氧化劑將錯合物[Ni5(npts)4]氧化，將所得到的產物進行鑑定，比較氧化前後在結構和磁性上的差異，作較系統的研究。

關鍵字

金屬串 ； 分子導線 ； 混價系統

並列摘要

According to the idea of tuning the ligand, ligand containing the naphthyridyl group, which can stabilize the low oxidation state metal ions and bulky sulfonyl group on the end was prepared. The unsymmetrical ligand H2npts was synthesized by palladium-catalyzed reaction, and was characterized by the 1H-NMR and ESI-Mass.
The ligand H2npts was applied to synthesize linear penta-nickel metal string complex [Ni5(npts)4], 1. The complex 1 was structurally characterized to reveal that five nickel ions are in the square planar environment. Because of the steric effect of the bulky p-toluenesulfonyl group, the complex 1 is in (2,2)-trans form, with no axial ligand. The complex is described as a mixed-valence system consisting of (Ni2)3+-Ni2+-(Ni2)3+ fragment. The terminal naphthyridyl groups can stabilize the [Ni2]3+ units. From the magnetic analysis, the complex 1 shows an antiferromagnetic interaction between two (Ni2)3+ units with J = -54.46 cm-1. Comparing with researches which contain naphthyridyl groups in the past, we found that the distance between the two (Ni2)3+ units is longer, and the antiferromagnetic interaction is weaker.
In the electrochemistry, the complex 1 has three pairs of reversible redox couples, one in reduction and two in oxidation. From this data, the complex 1 is easier to oxidize. In the future, we can oxidize the complex, and gain the product of two-electron oxidation. The product will be compared with the complex 1 in structure and magnetic properties. It will complete the series of the study.

並列關鍵字

Metal String ； Molecular Wire ； Mixed-Valence System

參考文獻

27. (a) F. A. Cotton, L. M. Daniel, C. A. Murillo, X. Wang, Inorg. Chem. 2001, 40, 2778. (b) X. Lopez, M. Y. Huang, G. C. Huang, S. M. Peng, F. Y. Li, M. Benard, M. M. Rohmer, Inorg. Chem. 2006, 45, 9075. (c)戴品仁，台大化學碩士論文，2011.

33. (a) S. M. Peng, C. C. Wang, Y. L. Chiang, Y. H. Chen, F. Y. Li, C. Y. Mou, M. K. Leung, J. Mag. Mag. Mater. 2000, 209, 80. (b) R. H. Ismayilov, W. Z. Wang, R. R. Wang, C. Y. Yeh, G. S. Lee, S. M. Peng, Chem. Comm. 2007, 1121.

13. (a) F. A. Cotton, N. F. Curtis, C. B. Harris, B. F. G. Johnson, S. J. Lippard, J. T. Mague, W. R. Robinson, J. S. Wood, Science. 1964, 145, 1305. (b) F. A. Cotton, N. F. Curtis, B. F. G. Johnson, W. R. Robinson, Inorg. Chem. 1965, 4, 326. (c) F. A. Cotton, C.B. Harris, Inorg. Chem. 1965, 4, 300.

1. S. Wagaw, S. L. Buchawald, J. Org. Chem. 1996, 61, 7240.

2. A. Aviram, M. A. Ratner, Chem. Phys. Lett. 1974, 29, 277.