- 作者: 賴旭洋 ; 王志傑 ; 陳裕華 ; 李忠洲 ; 劉怡宏 ; 彭旭明
- 作者服務機構: 台灣大學化學系
- 中文摘要: The synthesis, crystal structures and magnetic properties of linear heptanuclear nickel(II) complexes [Ni/sub 7/(.mu./sub 7/-teptra)/sub 4/X/sub 2/], (teptra = tetrapyridyltriamido), with the axial ligand X= Cl/sup -/(1), NCS/sup -/(2), are reported. The hepta-nuclear metal chain is helically wrapped by four syn-syn-syn-syn-syn-syn teptra/sup 3-/ ligands. Both of the [Ni/sub 7/(.mu./sub 7/-teptra)/sub 4/]/sup 2+/ moiety are isostructural involving a Ni/sub 7/ linear chain unit with all of the . ANGLE.Ni-Ni-Ni being 180.degree., terminated by two axial ligands. Three types of Ni-Ni distances are found in these complexes. The longest ones bonded with the axial ligands are 2.383(1), 2.374(2) and 2.375(2), 2.354(2), and the intermediate ones are 2.310(1), 2.304(1) and 2.300(2), 2.303(2) .ANG. for (1) and (2), respectively. The innermost Ni-Ni distances are the shortest ones with the distances of 2.226(2), 2.214(2) and 2.194(2), 2.206(2) .ANG. for (1) and (2), respectively. Two terminal Ni(II) ions bonded with the axial ligands are in a square-pyramidal (NiN/sub 4/X) environment and exhibit long Ni-N bonds (-2.10 .ANG.) which are consistent with a high-spin Ni(II) configuration. The inner five Ni(II) ions displayed short Ni-N (-1.90 .ANG.) bond distances which are consistent with a square-planar (NiN/sub 4/), diamagnetic arrangement of a low-spin Ni(II) configuration. The magnetic measurement of (1) shows an antiferromagnetic interaction of two terminal high-spin Ni(II) ions with the coupling constant J =-3.8cm/sup -1/. The Ni-Ni, Ni-N distances and magnetic behavior among tri-, penta-, and hepta-nickel(II) complexes are compared and discussed.
- 英文摘要: --
- 中文關鍵字: Ni-Ni String Complex; Metal-Metal Bond; Molecular Metalwire; Oligo-.Alpha.-Pyridylamido Complex
- 英文關鍵字: 鎳-鎳串錯合物;金屬-金屬鏈;分子金屬絲;寡-α-啶氨基錯合物