The coordination chemistry of 2,4-di(tert-butyl)pentadienyl revisited
The coordination chemistry of 2,4-di(tert-butyl)pentadienyl revisited
复制标题
DOI：
10.1016/j.ica.2014.06.020
复制
发表时间：
2014-10
影响因子：
2.8
通讯作者：
Matthias Reiners;D. Baabe;Peter Schweyen;M. Freytag;P. Jones;Marc D. Walter
中科院分区：
文献类型：
--
作者：
Matthias Reiners;D. Baabe;Peter Schweyen;M. Freytag;P. Jones;Marc D. Walter
研究了2，4-二叔丁基双（Pdl′）配体与过渡金属的配位化学。合成了几种开环戊二烯[（η5-Pdl′）2 M]（M = Ti（3），V（4）和Cr（5）），并通过各种光谱技术和X射线衍射进行了表征。开环二茂铁[（η5-Pdl′）2Fe]的热不稳定性阻碍了其制备，导致生成金属铁和2，4，7，9-四叔丁基-1，3，7，9-癸四烯（2）。然而，我们成功地合成了半开放的二茂铁[（η5-Pdl′）Fe（η5-Cp″）]（Cp″ = 1，2，4-（Me 3C）3C 5 H2，6）和单铱配合物[（η5-Pdl′）Ir（η4-cod）]（9）。比较了半开放式二茂铁[（η5-Pdl′）Fe（η5-Cp″）]（6）及其封闭式类似物[（η5-Cp′）Fe（η5-Cp″）]（7，Cp′ = 1，3-（Me 3C）2C 5 H3）的电子结构和分子结构. Pdl′与Fe的距离较短，表明配合物6比配合物7明显受阻。6和7的清洁氧化可以通过电化学和化学方法完成，分别得到半开放的二茂铁6+和封闭的二茂铁7+，在这两种情况下，氧化时都会释放空间应变。在固态下加热6+至152 °C时，除去H2和异丁烯，得到[（η5-Cp′）2Fe]+（8）。
The coordination chemistry of the previously neglected 2,4-di(tert-butyl)pentadienyl (Pdl′) ligand with transition metals is explored. Several open metallocenes [(η5-Pdl′)2M] (M = Ti (3), V (4) and Cr (5)) were prepared and characterized by various spectroscopic techniques and X-ray diffraction. Attempts to prepare the open ferrocene [(η5-Pdl′)2Fe] were hampered by its high thermal instability, which leads to the formation of iron metal and 2,4,7,9-tetra-tert-butyl-1,3,7,9-decatetraene (2). Nevertheless, the half-open ferrocene [(η5-Pdl′)Fe(η5-Cp″)] (Cp″ = 1,2,4-(Me3C)3C5H2,6) and mono(pentadienyl) iridium complex [(η5-Pdl′)Ir(η4-cod)] (9) were successfully synthesized. The electronic and molecular structures of the half-open ferrocene [(η5-Pdl′)Fe(η5-Cp″)] (6) and its closed analogue [(η5-Cp′)Fe(η5-Cp″)] (7, Cp′ = 1,3-(Me3C)2C5H3) were compared. Complex6is significantly more encumbered than7, as shown by the short Pdl′cent–Fe distance. Clean oxidation of6and7can be accomplished electrochemically and chemically to give the half-open ferrocenium6+and closed ferrocenium7+, respectively, and in both cases steric strain is released upon oxidation. On heating of6+to 152 °C in the solid state H2and isobutene is eliminated to give [(η5-Cp′)2Fe]+(8).