A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences, 119991, Moscow, Russian Federation.
Dalton Trans. 2012 Jan 21;41(3):737-46. doi: 10.1039/c1dt10500k. Epub 2011 Sep 7.
The nucleophilic substitution of six chlorine atoms of the n-butylboron-capped clathrochelate iron and cobalt(II) precursors with perfluoroarylthiolate anions afforded the hexaperfluoroarylsulfide macrobicyclic iron and cobalt(II) tris-dioximates. The complexes obtained are soluble in aromatic and aliphatic hydrocarbons as well as in polar aprotonic solvents due to the presence of the superhydrophobic fluorine-containing molecular periphery. As it follows from the X-ray data for five iron and cobalt mono- and bis-clathrochelates, the geometry of their macrobicyclic frameworks is affected by both the nature of an encapsulated metal ion and that of the ribbed substituents. Bis-capping fragment Co(II)O(6) of the Co(III)Co(II)Co(III) bis-clathrochelate possesses a trigonal antiprismatic geometry, all the Co(II)N(6) coordination polyhedra are trigonal-prismatic, and those of the encapsulated iron(II) and cobalt(III) ions are intermediate between them. The wide range of Co-N distances as well as the significant shifts of the encapsulated cobalt(II) ions from the centres of their N(6)-coordination polyhedra were explained by the Jahn-Teller distortion. The EPR and magnetometry data are also characteristic of the low-spin cobalt(II) complexes with this distortion. The parameters of the (57)Fe Mössbauer spectra of the iron macrobicycles are characteristic of the low-spin iron(II) complexes. The cyclic voltammograms (CVs) for the complexes studied contain the one-electron oxidation and reduction waves assigned to metal-centered redox-processes. The Fe(2+/3+) and Co(2+/3+) oxidations are quasi-reversible or irreversible. The anionic clathrochelate species resulting from the reversible Co(2+/+) reductions are stable on the CV time scale, whereas their iron(I)-containing analogs are unstable.
正丁基硼封端的笼形配合物铁和钴（II）前体的六个氯原子与全氟芳硫醇阴离子的亲核取代反应，得到了六全氟芳硫醚大环铁和钴（II）三二肟配合物。由于存在超疏水含氟分子外围，所得到的配合物可溶于芳烃和脂肪烃以及极性非质子溶剂。根据五个铁和钴单-和双-笼形配合物的 X 射线数据，其大环骨架的几何形状既受包封金属离子的性质影响，也受肋状取代基的性质影响。Co(III)Co(II)Co(III)双笼形配合物的 Co(II)O(6)双封端片段具有三角反棱柱几何形状，所有 Co(II)N(6)配位多面体都是三角棱柱体，而被包封的铁(II)和钴(III)离子的配位多面体则介于两者之间。Co-N 距离范围很宽，以及被包封的钴(II)离子从其 N(6)配位多面体的中心明显位移，这都可以用 Jahn-Teller 畸变来解释。EPR 和磁强计数据也表明了这种畸变的低自旋钴（II）配合物的特征。铁大环配合物的 (57)Fe Mössbauer 光谱参数特征为低自旋铁(II)配合物。所研究的配合物的循环伏安图（CV）包含一个电子氧化和还原波，其分配给金属中心的氧化还原过程。Fe(2+/3+)和 Co(2+/3+)的氧化是准可逆或不可逆的。来自 Co(2+/+)可逆还原的阴离子笼形配合物在 CV 时间尺度上是稳定的，而其含铁（I）的类似物则是不稳定的。
