Dihedral-Angle-Controlled Crossover from Static Hole Delocalization to Dynamic Hopping in Biaryl Cation Radicals
作者:Marat R. Talipov、Tushar S. Navale、Mohammad M. Hossain、Ruchi Shukla、Maxim V. Ivanov、Rajendra Rathore
DOI:10.1002/anie.201609695
日期:2017.1.2
In cases of coherent charge‐transfer mechanism in biaryl compounds the rates follow a squared cosine trend with varying dihedral angle. Herein we demonstrate using a series of biaryl cationradicals with varying dihedral angles that the hole stabilization shows two different regimes where the mechanism of the hole stabilization switches over from (static) delocalization over both aryl rings to (dynamic)
在联芳基化合物具有相干电荷转移机制的情况下,速率遵循具有二面角变化的余弦平方趋势。在本文中,我们证明了使用一系列具有不同二面角的联芳基阳离子自由基,空穴稳定化显示了两个不同的状态,其中空穴稳定化的机理从两个芳基环上的(静态)离域转换为(动态)跳跃。具有不同二面角的联芳烃的实验数据和DFT计算明确支持从离域到跳跃的交换发生在唯一的二面角处,其中电子耦合(H ab)是重组(λ)的一半,即H ab = λ/ 2。目前正在研究这一发现对非相干电荷传输速率的影响。
Aerobic Oxidative Intramolecular Aromatic Coupling<i>via</i>Heterogeneous Metal Catalysts
An aerobic, heterogeneously catalyzed oxidative intramolecular coupling reaction of aromatic compounds is reported here. Using commercially available, recyclable heterogeneous metal catalysts, the coupling reactions of o‐terphenyls and 1,ω‐biarylalkanes proceeded quickly under mild conditions, i.e., at room temperature under oxygen as a co‐oxidant almost all within 1 h, to provide the corresponding