Biswas Mrinmoy, Dule Madhab, Samanta Pabitra N, Ghosh Sharmistha, Mandal Tarun K
Polymer Science Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
Phys Chem Chem Phys. 2014 Aug 14;16(30):16255-63. doi: 10.1039/c4cp01324g.
The thermal phase behaviors of a series of newly designed 1-alkyl-3-methylimidazolium ionic liquids (ILs) of different chain length fatty acid carboxylate anions are investigated. The length of the alkyl chain of the carboxylate anion in IL influences the phase transition temperature of their crystalline solid phase and the mesophase stability. When the palmitate anion of the IL is replaced with palmitoyl ascorbate and palmitoyl-L-tryptophanate anions, its melting temperature decreases and eventually vanishes. The influence of structural modulation of ILs on their ionic conductivities is also studied. The interaction between the 1-alkyl-3-methylimidazolium cation and the fatty acid carboxylate anion is established by using ab initio based DFT calculations. The associated energies for single ion pair formation of these ILs are computed and are successfully correlated with the experimental findings, which finally leads to the most reasonable arrangement of the IL molecules in different phases.
研究了一系列新设计的、具有不同链长脂肪酸羧酸根阴离子的1-烷基-3-甲基咪唑鎓离子液体（ILs）的热相行为。IL中羧酸根阴离子的烷基链长度会影响其晶相的相变温度和中间相稳定性。当IL中的棕榈酸根阴离子被棕榈酰抗坏血酸根和棕榈酰-L-色氨酸根阴离子取代时，其熔点降低并最终消失。还研究了ILs结构调制对其离子电导率的影响。通过基于从头算的密度泛函理论（DFT）计算，确定了1-烷基-3-甲基咪唑鎓阳离子与脂肪酸羧酸根阴离子之间的相互作用。计算了这些ILs单离子对形成的缔合能，并成功地将其与实验结果相关联，最终得出了IL分子在不同相中的最合理排列。
