Iron(II) and cobalt(II) complexes of tris-azinyl analogues of 2,2′:6′,2"-terpyridine
Iron(II) and cobalt(II) complexes of tris-azinyl analogues of 2,2′:6′,2"-terpyridine
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DOI：
10.1039/c2dt31736b
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发表时间：
2013-01-01
影响因子：
4
通讯作者：
Halcrow, Malcolm A.
中科院分区：
文献类型：
--
作者：
Cook, Laurence J. Kershaw;Tuna, Floriana;Halcrow, Malcolm A.
报道了2，6-二（吡啶-2-基）吡嗪（L-1）、2，6-二（吡嗪基）吡啶（L-2）、2，2 '：6'，2“-三联吡嗪（L-3）、2，6-二（嘧啶-4-基）吡啶（L-4）、2，6-二（1，2，4-三嗪-3-基）吡啶（L-5）、4-羟基-2，6-二（吡嗪基）吡啶（L-6）和4-羟基-2，6-二（嘧啶-2-基）吡啶（L-7）的合成。均配型铁（II）和钴（II）这些配体的配合物已制备，并在四种情况下，结构特征。铁络合物都是低自旋的。然而，虽然富含吡嗪的配体L-2、L-3和L-6的钴络合物在固态下都主要是低自旋的，但其它钴络合物在5-300 K之间基本上是高自旋的。伏安M（III）/（II）（M = Fe或Co）氧化和金属或配体为基础的还原都变得更加阳极的配体的氮含量的增加，这与杠杆的添加剂的电化学参数的杂环供体基团在每个复杂的。
The syntheses of 2,6-di(pyrid-2-yl)pyrazine (L-1), 2,6-di(pyrazinyl)pyridine (L-2), 2,2':6',2 ''-terpyrazine (L-3), 2,6-di(pyrimidin-4-yl)pyridine (L-4), 2,6-di(1,2,4-triazin-3-yl)pyridine (L-5), 4-hydroxy-2,6-di(pyrazinyl)-pyridine (L-6) and 4-hydroxy-2,6-di(pyrimidin-2-yl)pyridine (L-7) are described. Homoleptic iron(II) and cobalt(II) complexes of these ligands have been prepared and, in four cases, structurally characterised. The iron complexes are all low-spin. However, while the cobalt complexes of the pyrazine-rich ligands L-2, L-3 and L-6 are all predominantly low-spin in the solid state, the other cobalt complexes are essentially high-spin between 5-300 K. The voltammetric M(III)/(II) (M = Fe or Co) oxidations and metal- or ligand-based reductions all become more anodic as the nitrogen content of the ligands increases, which correlates well with Lever's additive electrochemical parameters for the heterocyclic donor groups in each complex.