Key Laboratory for Advanced Materials and Department of Chemistry, East China University of Science and Technology , Shanghai 200237, China.
J Phys Chem A. 2014 Apr 3;118(13):2508-18. doi: 10.1021/jp4125167. Epub 2014 Mar 21.
Transition metal-containing ionic liquids (TM-ILs) have attracted a great deal of attention in recent years, due to their unique physical and chemical properties. In this work, several representative TM-ILs, such as the cations consisting of silver(I) center coordinated by two n-alkylimidazole ligands ((C(n)(im))Ag(mim)) and the anions involving mercury(II) (HgCl3(-)), zinc(II) (ZnCl3(-)), and rhenium(VII) (ReO4(-)), were investigated using density functional theory calculations. First, the structural and energetic properties of the ion pairs for these TM-ILs have been examined in detail and compared with properties for conventional ILs. It was found that the interactions between the cations and anions, including hydrogen bonds and electrostatic interactions, in TM-ILs become weaker in strength than those in traditional ILs. In particular, the calculated geometric and energetic features compare fairly well with the experimental results, such as melting points and X-ray crystal structures of these TM-ILs. Then, the structures and energetics of ion-pair dimers for three ILs containing HgCl3(-), ZnCl3(-), and ReO4(-) were also explored, to gain a deeper understanding of the properties of TM-ILs. Finally, a survey of the Cambridge Structural Database (CSD) was undertaken to provide some crystallographic implications of TM-ILs.
过渡金属离子液体（TM-ILs）由于其独特的物理化学性质，近年来引起了极大的关注。在这项工作中，使用密度泛函理论计算研究了几种代表性的 TM-ILs，例如由两个 n-烷基咪唑配体配位的银（I）中心组成的阳离子[（（C（n）（im））Ag（mim）]（+）和涉及汞（II）（HgCl3（-））、锌（II）（ZnCl3（-））和铼（VII）（ReO4（-））的阴离子。首先，详细研究了这些 TM-ILs 的离子对的结构和能量特性，并与传统 ILs 的特性进行了比较。结果发现，TM-ILs 中阳离子和阴离子之间的相互作用（包括氢键和静电相互作用）的强度比传统 ILs 中的相互作用弱。特别是，计算得到的几何和能量特征与这些 TM-ILs 的实验结果，如熔点和 X 射线晶体结构，相当吻合。然后，还研究了含有 HgCl3（-）、ZnCl3（-）和 ReO4（-）的三种 IL 的离子对二聚体的结构和能量，以更深入地了解 TM-ILs 的性质。最后，对剑桥结构数据库（CSD）进行了调查，以提供一些 TM-ILs 的晶体学含义。
