Department of Physics, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
J Mol Model. 2021 May 23;27(6):180. doi: 10.1007/s00894-021-04796-z.
In this work, we have theoretically studied the dicationic ionic liquids (DILs) constructed from geminal methylimidazolium dication with varying amino acid anions and spacers using density functional theory. Amino acid-based DILs form via strong C-H···O hydrogen bonds. These hydrogen bonds have a significant role in stabilizing the DILs. The higher cation-anion interaction energy in the order of covalent bond energy and liquid density of DILs imply higher thermal stability than their mono analogues. The C-H stretching frequencies are above 3100 cm in all complexes and form a signature for DILs. Interestingly, aliphatic and aromatic amino acid anions show similar molecular properties. Overall, the DILs formed from amino acids exhibit high stability and large surface tension and are chemically non-toxic; hence, they can replace inorganic DILs.
在这项工作中，我们使用密度泛函理论理论上研究了由偕二甲基咪唑二阳离子与不同氨基酸阴离子和间隔基构建的二价离子液体（DIL）。基于氨基酸的 DIL 通过强 C-H···O 氢键形成。这些氢键在稳定 DIL 方面起着重要作用。DIL 的阳离子-阴离子相互作用能高于共价键能和液体密度的顺序，这意味着它们比其单模拟物具有更高的热稳定性。所有配合物中的 C-H 伸缩振动频率均高于 3100 cm，形成 DIL 的特征。有趣的是，脂肪族和芳香族氨基酸阴离子表现出相似的分子性质。总的来说，由氨基酸形成的 DIL 表现出高稳定性、大表面张力和化学无毒；因此，它们可以替代无机 DIL。
