Formation of a solubilized cobalt block oligomer from a M<sub>2</sub>L-type double helicate
作者:Fenton Heirtzler、Saverio Santi、Kevin Howland、Thomas Weyhermüller
DOI:10.1039/b605512e
日期:——
The multi-dentate ligand, 2,3,5,6-tetrakis(2,2′-bipyridyl)pyrazine (L) and divalent cobalt self-assemble to a block co-polymer-like oligomer in solution, which contains at least the L7Co8 fragment. The extent of oligomerization is sensitive to the water content in acetonitrile solution. In the solid state, the simple monomer [LCo2(CH3CN)4][ClO4]4 is isolated. The X-ray structure of the crystallized material (containing four CH3CN solvate molecules) reveals a double-helical complex with two heptadentate Co(II) sites, and a helical pitch of ∼28.1 Å. Coupled Co(I/II) redox processes are observed between the two metal centres.
多齿配体、2,3,5,6-四(2,2'-联吡啶基)吡嗪(L)和二价钴在溶液中自组装成嵌段共聚物状低聚物,该低聚物至少包含L7Co8 片段。低聚的程度对乙腈溶液中的水含量敏感。在固态下,分离出简单单体[LCo2(CH3CN)4][ClO4]4。结晶材料(含有四个 CH3CN 溶剂化物分子)的 X 射线结构揭示了具有两个七齿 Co(II) 位点的双螺旋复合物,螺距约为 28.1 Å。在两个金属中心之间观察到耦合的 Co(I/II) 氧化还原过程。