Inokuchi Yoshiya, Rizzo Thomas R
Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland.
J Phys Chem Lett. 2025 Aug 14;16(32):8125-8132. doi: 10.1021/acs.jpclett.5c02081. Epub 2025 Aug 1.
We obtained gas-phase UV and IR spectra of 1:2 potassium ion-crown ether (CE) complexes (benzo-15-crown-5 (B15C5), benzo-18-crown-6 (B18C6), dibenzo-18-crown-6 (DB18C6), and 18-crown-6 (18C6)) at approximately 10 K and determined the structure and intermolecular interactions between K and the two CEs, supported by quantum chemical calculations. The vibronic features of K(B15C5) revealed two conformers in the UV photodissociation spectrum, and the K ion was held equally by both B15C5 moieties. For K(B18C6) and K(DB18C6), the K ions were not equally shared between the two CEs. For K(B18C6)(18C6) and K(DB18C6)(18C6), the K ion mainly interacted with 18C6, and the interaction between K and B18C6 or DB18C6 was very weak. In contrast, K(B18C6)(18C6) produced photofragment K(B18C6) ion exclusively, whereas K(DB18C6)(18C6) produced K(18C6). The photodissociation of K(B18C6)(18C6) indicates that K transfer from 18C6 to B18C6 occurs upon UV excitation, probably in the electronically excited states.
我们获得了1:2钾离子-冠醚（CE）配合物（苯并-15-冠-5（B15C5）、苯并-18-冠-6（B18C6）、二苯并-18-冠-6（DB18C6）和18-冠-6（18C6））在约10 K时的气相紫外和红外光谱，并通过量子化学计算确定了K与两个CE之间的结构和分子间相互作用。K（B15C5）的振动电子特征在紫外光解离光谱中显示出两种构象，K离子由两个B15C5部分平等地保持。对于K（B18C6）和K（DB18C6），K离子在两个CE之间并非平等共享。对于K（B18C6）（18C6）和K（DB18C6）（18C6），K离子主要与18C6相互作用，而K与B18C6或DB18C6之间的相互作用非常弱。相比之下，K（B18C6）（18C6）仅产生光碎片K（B18C6）离子，而K（DB18C6）（18C6）产生K（18C6）。K（B18C6）（18C6）的光解离表明，在紫外激发时，可能在电子激发态下，K从18C6转移到B18C6。
