Manipulation and Assessment of Charge and Spin Delocalization in Mixed-Valent Triarylamine-Vinylruthenium Conjugates.
Manipulation and Assessment of Charge and Spin Delocalization in Mixed-Valent Triarylamine-Vinylruthenium Conjugates.
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DOI：
10.1021/acs.inorgchem.7b02186
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发表时间：
2017-10
影响因子：
4.6
通讯作者：
Christopher Hassenrück;R. Winter
中科院分区：
文献类型：
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作者：
Christopher Hassenrück;R. Winter
合成了三芳胺-乙烯基钌配合物（4-RC_6 H_4）_2N{C_6 H_4 -4-CH_CHRu（CO）Cl（PiPr_3）_2}，其中R = CHO（1-CHO），C（CH_2O）Me（1-Ac），COOMe（1-E），Me（1-Me）。和量子化学计算。与4-OMe取代的三芳基胺-乙烯基钌缀合物1-OMe相比，三芳基胺部分的吸电子取代基将电荷和自旋密度向更富电子的乙烯基钌位点移动。一个更不对称的电荷分布改变了强烈的振动结构的价间电荷转移（IVCT）带完全离域，混合价（MV）1-OMe+到一个较弱的，高度不对称的，nonsolvatochromic带在低能量侧的带宽显着较小。甲酰基衍生物1-CHO+的IVCT带的温度依赖性证明了IVCT过渡到对称振动的振动耦合是带偏斜的根本原因。我们所有的结果表明，MV自由基阳离子保持电子强耦合，尽管越来越强的偏置的最高占据分子轨道的乙烯基钌实体。此外，这些配合物的dications被发现是顺磁性的，这使得它们罕见的化合物的例子，联合收割机强电子耦合在阳离子MV状态与顺磁性的dications。
Triarylamine-vinylruthenium conjugates (4-RC6H4)2N{C6H4-4-CH═CHRu(CO)Cl(PiPr3)2}, with R = CHO (1-CHO), C(═O)Me (1-Ac), COOMe (1-E), and Me (1-Me), have been prepared and investigated in their neutral, mono- and dioxidized states by cyclic voltammetry, IR, and UV/vis/near-infrared spectroelectrochemistry, electron paramagnetic resonance spectroscopy, and quantum-chemical calculations. Electron-withdrawing substituents at the triarylamine moiety shift the charge and spin density toward the more electron-rich vinylruthenium site in comparison to the 4-OMe-substituted triarylamine-vinylruthenium conjugate 1-OMe. A more asymmetric charge distribution changes the intense vibrationally structured intervalence charge-transfer (IVCT) band of completely delocalized, mixed-valent (MV) 1-OMe+ to a weaker, highly asymmetric, nonsolvatochromic band with significantly smaller bandwidth at the low-energy side. The temperature dependence of the IVCT band of the formyl derivative 1-CHO+ proves that vibrational coupling of the IVCT transition to a symmetrical vibration is the underlying reason for band skewing. All of our results indicate that the MV radical cations remain electronically strongly coupled despite an increasingly stronger bias of the highest occupied molecular orbital to the vinylruthenium entity. Moreover, the dications of these complexes were found to be paramagnetic, which makes them rare examples of compounds that combine strong electronic coupling in the cationic MV state with paramagnetism of the dications.