Synthesis and characterization of novel ferrocene-containing pyridylamine ligands and their ruthenium(II) complexes: electronic communication through hydrogen-bonded amide linkage.
Synthesis and characterization of novel ferrocene-containing pyridylamine ligands and their ruthenium(II) complexes: electronic communication through hydrogen-bonded amide linkage.
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DOI：
10.1021/ic7016038
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发表时间：
2008-01
影响因子：
4.6
通讯作者：
Takahiko Kojima;Daisuke Noguchi;T. Nakayama;Y. Inagaki;Y. Shiota;K. Yoshizawa;K. Ohkubo;S. Fukuzumi
中科院分区：
文献类型：
--
作者：
Takahiko Kojima;Daisuke Noguchi;T. Nakayama;Y. Inagaki;Y. Shiota;K. Yoshizawa;K. Ohkubo;S. Fukuzumi
合成了在TPA的1个或2个吡啶环的6位上具有1个或2个二茂铁酰胺部分的三(2-吡啶甲基)胺(TPA)衍生物。采用光谱法、循环伏安法和 X 射线对化合物 N-(6-二茂铁酰胺-2-吡啶基甲基)-N,N-双(2-吡啶基甲基)胺 (Fc-TPA; L1) 和 N,N-双(6-二茂铁酰胺-2-吡啶基甲基)-N-(2-吡啶基甲基)胺 (Fc2-TPA; L2) 进行了表征。晶体学。还制备了它们的 Ru(II) 配合物，并通过光谱方法、循环伏安法和 X 射线晶体学进行了表征。 [RuCl(L1)(DMSO)]PF(6) (1) 含有 S-结合的二甲基亚砜 (DMSO) 作为配体和未配位的二茂铁酰胺部分，分别由于 Fc/Fc(+) 和 Ru(II)/Ru(III) 氧化还原对而在 0.23 和 0.77 V 处表现出两个氧化还原波（相对于二茂铁/二茂铁鎓离子为 0 V）。含有配位和不配位酰胺部分的[RuCl(L2)]PF(6) (2)显示出在0.27 V（两个电子）和0.46 V（一个电子）处观察到的两个氧化还原波，分别归因于与不配位的Fc/Fc(+)氧化还原对和配位的Fc/Fc(+)重叠的Ru(II)/Ru(III)氧化还原对。与2相比，乙腈配合物[Ru(L2)(CH(3)CN)](PF(6))(2) (3)在0.26和0.37 V两种Fc/Fc(+)对中表现出三种氧化还原对，而在Ru(II)/Ru(III)对中表现出0.83 V（相对于二茂铁/二茂铁鎓离子为0 V）。在该复合物中，配位和非配位 Fc-酰胺部分的氧化还原电位在 0.11 V 范围内进行区分。1 的化学双电子氧化得到 [RuIIICl(L1+)(DMSO)](3+)，生成铁磁耦合三重态 (S = 1)，J = 13.7 cm-1 (H = -JS(1)S(2))，这是通过其变温电子估计的CH(3)CN 中的自旋共振 (ESR) 谱。 Ru(III) 中心和 Fe(III) 中心的电子自旋通过酰胺键进行铁磁耦合。在2的情况下，其双电子氧化给出了相同的ESR光谱，这表明形成了类似的三重态。这种电子通讯可以通过形成分子内氢键的酰胺键发生。
Tris(2-pyridylmethyl)amine (TPA) derivatives with one or two ferrocenoylamide moieties at the 6-position of one or two pyridine rings of TPA were synthesized. The compounds, N-(6-ferrocenoylamide-2-pyridylmethyl)-N,N-bis(2-pyridylmethyl)amine (Fc-TPA; L1) and N,N-bis(6-ferrocenoylamide-2-pyridylmethyl)-N-(2-pyridylmethyl)amine (Fc2-TPA; L2), were characterized by spectroscopic methods, cyclic voltammetry, and X-ray crystallography. Their Ru(II) complexes were also prepared and characterized by spectroscopic methods, cyclic voltammetry, and X-ray crystallography. [RuCl(L1)(DMSO)]PF(6) (1) that contains S-bound dimethyl sulfoxide (DMSO) as a ligand and an uncoordinated ferrocenoylamide moiety exhibited two redox waves at 0.23 and 0.77 V (vs ferrocene/ferrocenium ion as 0 V), due to Fc/Fc(+) and Ru(II)/Ru(III) redox couples, respectively. [RuCl(L2)]PF(6) (2) that contains both coordinated and uncoordinated amide moieties showed two redox waves that were observed at 0.27 V (two electrons) and 0.46 V (one electron), assignable to Ru(II)/Ru(III) redox couples overlapped with the uncoordinated Fc/Fc(+) redox couple and the coordinated Fc/Fc(+), respectively. In contrast to 2, an acetonitrile complex, [Ru(L2)(CH(3)CN)](PF(6))(2) (3), exhibited three redox couples at 0.26 and 0.37 V for two kinds of Fc/Fc(+) couples, and 0.83 V for the Ru(II)/Ru(III) couple (vs ferrocene/ferrocenium ion as 0 V). In this complex, the redox potentials of the coordinated and the uncoordinated Fc-amide moieties were discriminated in the range of 0.11 V. Chemical two-electron oxidation of 1 gave [RuIIICl(L1+)(DMSO)](3+) to generate a ferromagnetically coupled triplet state (S = 1) with J = 13.7 cm-1 (H = -JS(1)S(2)) which was estimated by its variable-temperature electron spin resonance (ESR) spectra in CH(3)CN. The electron spins at the Ru(III) center and the Fe(III) center are ferromagnetically coupled via an amide linkage. In the case of 2, its two-electron oxidation gave the same ESR spectrum, which indicates formation of a similar triplet state. Such electronic communication may occur via the amide linkage forming the intramolecular hydrogen bonding.