Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9, Canada.
Inorg Chem. 2012 Oct 15;51(20):11155-67. doi: 10.1021/ic301777y. Epub 2012 Sep 25.
Salt-metathesis reactions between dilithioferrocene (Li(2)fc·2/3tmeda) and intramolecularly coordinated aluminum and gallium species RECl(2) [R = 5-Me(3)Si-2-(Me(2)NCH(2))C(6)H(3); E = Al (2a), Ga (2b); and R = (2-C(5)H(4)N)Me(2)SiCH(2); E = Al (3a), Ga (3b)] gave respective [1.1]ferrocenophanes ([1.1]FCPs). Those obtained from 2a and 2b, respectively, were isolated as analytically pure compounds and fully characterized including single-crystal X-ray structure determinations [4a (Al): 43%; 4b (Ga): 47%]. Bis(ferrocenyl) compounds of the type REFc(2) [R = 5-Me(3)Si-2-(Me(2)NCH(2))C(6)H(3); E = Al (5a), Ga (5b); and R = (2-C(5)H(4)N)Me(2)SiCH(2); E = Al (6a), Ga (6b)] and R(2)SiFc(2) [R = Me (7(Me)); Et (7(Et))] were prepared, starting from respective element dichlorides and lithioferrocene (LiFc). Molecular structures of 6a, 7(Me), and 7(Et) were solved by single-crystal X-ray analyses. One of the two Fc moieties of 6a was bent toward the open coordination site of the aluminum atom. The measured dip angles α* of the two independent molecules in the asymmetric unit were 11.9(5) and 13.3(5)°, respectively. The redox behavior of [1.1]FCPs 4 and bis(ferrocenyl) species 5, 6, 7, and (Mamx)EFc(2) [Mamx = 2,4-tBu(2)-6-(Me(2)NCH(2))C(6)H(2); E = Al (8a), Ga (8b)] were investigated with cyclic voltammetry. While all gallium and silicon compounds gave meaningful and interpretable data, all aluminum compounds were problematic with the exception of 8a. Aluminum species, compared to respective gallium species, are more sensitive and, presumably, fluoride ions or residual water from the electrolyte and solvent are causing degradation. The splitting between the formal potentials for bis(ferrocenyl) species was significantly smaller (5b, 6b, and 8b: ΔE°' = 0.138-0.159 V) than that of the [1.1]FCP 4b (ΔE°' = 0.309 V). These results were explained by assuming an electrostatic interaction between the two iron centers; differences between bis(ferrocenyl) species and [1.1]FCPs are likely due to a more effective solvation of Fe-containing moieties in the more flexible bis(ferrocenyl) species.
二锂二茂铁（Li(2)fc·2/3tmeda）与分子内配位的铝和镓物种 RECl(2) [R = 5-Me(3)Si-2-(Me(2)NCH(2))C(6)H(3); E = Al (2a), Ga (2b); 和 R = (2-C(5)H(4)N)Me(2)SiCH(2); E = Al (3a), Ga (3b)] 之间的盐-复分解反应分别生成相应的[1.1]二茂铁菲咯啉([1.1]FCPs)。分别从 2a 和 2b 获得的那些以分析纯化合物的形式分离出来，并进行了全面表征，包括单晶 X 射线结构测定[4a(Al):43%;4b(Ga):47%]。双(二茂铁基)化合物类型的 REFc(2) [R = 5-Me(3)Si-2-(Me(2)NCH(2))C(6)H(3); E = Al (5a), Ga (5b); 和 R = (2-C(5)H(4)N)Me(2)SiCH(2); E = Al (6a), Ga (6b)] 和 R(2)SiFc(2) [R = Me (7(Me)); Et (7(Et))] 是从各自的元素二氯化物和二茂铁(LiFc)开始制备的。通过单晶 X 射线分析确定了 6a、7(Me)和 7(Et)的分子结构。6a 的两个 Fc 部分之一弯曲朝向铝原子的开放配位位。在不对称单元中的两个独立分子的测量的二面角α*分别为 11.9(5)和 13.3(5)°。[1.1]FCPs 4 和双(二茂铁基)物种 5、6、7 和 (Mamx)EFc(2) [Mamx = 2,4-tBu(2)-6-(Me(2)NCH(2))C(6)H(2); E = Al (8a), Ga (8b)] 的氧化还原行为通过循环伏安法进行了研究。虽然所有的镓和硅化合物都给出了有意义和可解释的数据，但所有的铝化合物都存在问题，除了 8a。与相应的镓化合物相比，铝化合物更敏感，可能是由于电解质和溶剂中的氟化物离子或残留水造成了降解。双(二茂铁基)物种的形式电位之间的分裂明显更小(5b、6b 和 8b:ΔE°'=0.138-0.159 V)，而[1.1]FCP 4b(ΔE°'=0.309 V)的分裂更小。这些结果可以通过假设两个铁中心之间的静电相互作用来解释；双(二茂铁基)物种和[1.1]FCPs 之间的差异可能是由于在更灵活的双(二茂铁基)物种中，含 Fe 部分的溶剂化更有效。
