School of Chemistry and Chemical Engineering, The QUILL Centre, Queen's University Belfast, Belfast, UK BT9 5AG.
Phys Chem Chem Phys. 2010 Feb 28;12(8):1842-53. doi: 10.1039/b921160h. Epub 2010 Jan 18.
Liquid charge-transfer (CT) complexes were observed to form on contacting electron-rich aromatics with electron withdrawing group appended 1-alkyl-4-cyanopyridinium ionic liquids (ILs). Cooling below the melting point of the ionic liquid resulted in crystallisation of ionic liquid from the complex for 2-cyano and 3-cyano pyridinium isomers and in the formation of a 1 : 1 IL : aromatic crystalline CT-complex with the 4-cyanopyridinium isomer. The liquid structure of a 1 : 1 mixture of 1-methyl-4-cyanopyridinium bis{(trifluoromethyl)sulfonyl}imide with 1-methylnaphthalene has been probed by neutron diffraction experiments and molecular dynamics simulations. A high degree of correlation between the experimental data and the simulations was found with a significant displacement of the anions from around the cation by the aromatic species and the resulting structure having pi-pi stacks between the cations and the aromatic.
在接触富电子芳烃和带有吸电子基团的 1-烷基-4-氰基吡啶鎓离子液体 (IL) 时，观察到形成了液态电荷转移 (CT) 配合物。将温度降低到离子液体的熔点以下，对于 2-氰基和 3-氰基吡啶鎓异构体，离子液体从配合物中结晶，而对于 4-氰基吡啶鎓异构体，则形成了 1:1 的 IL:芳烃结晶 CT 配合物。通过中子衍射实验和分子动力学模拟研究了 1:1 混合物 1-甲基-4-氰基吡啶鎓双(三氟甲基磺酰基)亚胺与 1-甲基萘的液态结构。实验数据与模拟之间存在高度相关性，阴离子被芳烃显著取代，导致阳离子和芳烃之间存在π-π堆叠。
