Yang Yi-Fan, Cederbaum Lorenz S
Theoretical Chemistry, Institute of Physical Chemistry, Universität Heidelberg, Im Neuenheimer Feld 229, Heidelberg, Germany.
Angew Chem Int Ed Engl. 2021 Jul 19;60(30):16649-16654. doi: 10.1002/anie.202105222. Epub 2021 Jun 17.
By employing accurate state-of-the-art many-electron quantum-chemistry methods, we establish that monocyclic carbon rings can accommodate Li guest atoms. The low-lying electronic states of these endocircular systems are analyzed and found to include both charge-separated states where the guest Li atom appears as a cation and the ring as an anion and encircled-electron states where Li and the ring are neutral. The electron binding energies of the encircled-electron states increase drastically at their highly symmetric equilibrium geometries with increasing size of the ring, and in Li@C , this state becomes the ground state. Li is very weakly bound vertical to the rings in the low-lying encircled-electron states, hinting to van-der-Waals binding. Applcations are mentioned.
通过采用精确的最先进的多电子量子化学方法，我们确定单环碳环可以容纳锂客体原子。对这些内圆系统的低电子态进行了分析，发现其中包括电荷分离态（客体锂原子表现为阳离子，环表现为阴离子）和环绕电子态（锂和环均为中性）。环绕电子态的电子结合能在其高度对称的平衡几何结构下随着环尺寸的增加而急剧增加，在Li@C中，这种状态成为基态。在低能环绕电子态中，锂垂直于环的结合非常弱，这暗示着范德华结合。文中还提到了应用。
