Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany.
State Key Laboratory of Physical Chemistry of Solid Surface, National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P.R. China.
Angew Chem Int Ed Engl. 2017 Jan 2;56(1):397-400. doi: 10.1002/anie.201609101. Epub 2016 Dec 15.
The neutral radical (Me -cAAC) AlCl (2) is stabilized by cyclic (alkyl)(amino)carbenes (cAACs). Complex 2 was synthesized by reduction of the Me -cAAC:→AlCl (1) adduct with KC in the presence of another equivalent of Me -cAAC. The crystal structure of 2 shows that the Al-C bond lengths of the two carbenes bound to the Al center are considerably different, which is likely the result of intermolecular interactions. Quantum-chemical calculations from the gas phase give an equilibrium structure with identical Al-C bond lengths. Compound 2 exhibits monoradical character, which was confirmed by EPR measurements. A bonding analysis indicates that the unpaired electron resides mainly at the carbene carbon atoms. Compound 2 is an example for an unusual neutral Al radical.
中性自由基（Me-cAAC）AlCl（2）由环状（烷基）（氨基）卡宾（cAACs）稳定。通过在存在另一个当量的 Me-cAAC 的情况下用 KC 还原 Me-cAAC:→AlCl（1）加合物来合成 2。2 的晶体结构表明，与 Al 中心结合的两个卡宾的 Al-C 键长度有很大差异，这可能是分子间相互作用的结果。气相中的量子化学计算给出了具有相同 Al-C 键长度的平衡结构。化合物 2 表现出单自由基特征，这通过 EPR 测量得到证实。键分析表明，不成对电子主要位于卡宾碳原子上。化合物 2 是一个不寻常的中性 Al 自由基的例子。
