Linear Hydrocarbon Chain Growth from a Molecular Diruthenium Carbide Platform
Linear Hydrocarbon Chain Growth from a Molecular Diruthenium Carbide Platform
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分子碳化二钌平台的线性烃链增长
DOI：
10.1021/jacs.1c06586
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发表时间：
2021
影响因子：
15
通讯作者：
Matsuzaka Hiroyuki
中科院分区：
文献类型：
--
作者：
Ohata Jun;Teramoto Akira;Fujita Hiroaki;Takemoto Shin;Matsuzaka Hiroyuki
通过C1单元在金属表面上的顺序偶联形成线性烃链是费托合成（F-T）的核心部分。有机络合物提供了许多相关的个别C-C耦合事件的模型，但未能再现完整的链延长序列，将线性Cn烃链转化为它的Cn+1同系物在一个迭代的方式。在这项工作中，我们展示了逐步增长的线性Cn烃链和它们的转化为它们的Cn+1同系物通过连续添加的CH 2单元上的分子二碳化钌平台。通过μ-碳基络合物[（Cp*Ru）2（η-NPh）（μ-C）]（1; Cp* = η5-C5 Me 5）和Ph 2SCH 2之间的C + CH 2偶联形成μ-η1：η1-C = CH 2配体来启动链增长序列。然后，该链通过一般的C CH + CH 2偶联和随后的氢辅助异构化所得到的联烯配体μ-η1：η3-H2 C C C H到更高的亚乙烯基同系物μ-η1：η1-C CH（CH 2）R而增长。通过重复该反应序列，以逐步的方式合成了多达C6链。该链同系化序列的关键步骤是μ-η1：η3-联烯单元选择性氢化成相应的μ-亚烷基配体。同位素标记和计算研究表明，这种转化是通过联烯配体氢化为末端烯烃形式及其异构化为μ-亚烷基配体而进行的，该异构化由配位不饱和双钌平台促进。
The formation of linear hydrocarbon chains by sequential coupling of C1units on the metal surface is the central part of the Fischer–Tropsch (F-T) synthesis. Organometallic complexes have provided numerous models of relevant individual C–C coupling events but have failed to reproduce the complete chain lengthening sequence that transforms a linear Cnhydrocarbon chain into its Cn+1homologue in an iterative fashion. In this work, we demonstrate stepwise growth of linear Cnhydrocarbon chains and their conversion to their Cn+1homologues via consecutive addition of CH2units on a molecular diruthenium carbide platform. The chain growth sequence is initiated by the formation of a μ-η1:η1-C═CH2ligand from a C + CH2coupling between the μ-carbido complex [(Cp*Ru)2(η-NPh)(μ-C)] (1; Cp* = η5-C5Me5) and Ph2SCH2. Then, the chain propagates via a general C═CHR + CH2coupling and subsequent hydrogen-assisted isomerization of the resulting allene ligand μ-η1:η3-H2C═C═CHR to a higher vinylidene homologue μ-η1:η1-C═CH(CH2)R. By repeating this reaction sequence, up to C6chains have been synthesized in a stepwise fashion. The key step of this chain homologation sequence is the selective hydrogenation of the μ-η1:η3-allene unit to the corresponding μ-alkylidene ligand. Isotope labeling and computational studies indicate that this transformation proceeds via the hydrogenation of the allene ligand to a terminal alkene form and its isomerization to the μ-alkylidene ligand facilitated by the coordinatively unsaturated diruthenium platform.