Structures and Electronic Properties of Lithium Chelate-Based Ionic Liquids

Abstract

The conformations, electronic properties, and interaction energies of four chelate-based ionic liquids [Li(EA)][Tf2N], [Li(HDA)][Tf2N], [Li(DEA)][Tf2N], and [Li(DOBA)][Tf2N] have been theoretically explored. The reliability of the located conformers has been confirmed via the comparison between the simulated and experimental infrared spectra. Our results show that the N-Li and O-Li coordinate bonds in cation are elongated as the numbers of coordinate heteroatoms of alkanolamine ligands to Li(+) increased. Also the binding energies between Li(+) and ligands are increased and the interaction energies between cations and Tf2N anion are decreased. The cation-anion interaction energies follow the order of [Li(DOBA)][Tf2N] < [Li(HDA)][Tf2N] < [Li(DEA)][Tf2N] < [Li(EA)][Tf2N], which fall within the energetic ranges of conventional ionic liquids. Interestingly, the strongest stabilization orbital interactions in these ionic liquids and their cations revealed by the natural bond orbital analysis lie in the interaction between the lone pair (LP) of the coordinate heteroatoms in ligands or anion as donors and the vacant valence shell nonbonding orbital (LP*) of Li(+) as acceptors, which are very different from that of conventional ionic liquids. Moreover, the charges transferred from cations to anion are quite similar, and the charge of Li(+) is proposed for possibly predicting the order of the interaction energies of ionic liquids in series. The present study allows for the deeper understanding the differences between chelate-based ionic liquids and conventional ionic liquids.

LiCl-promoted-dehydration of fructose-based carbohydrates into 5-hydroxymethylfurfural in isopropanol

“…In a word, the efficient production of HMF from fructose in LiCl/i-PrOH system is achieved through the LiCl-promoted and i-PrOH-aided dehydration of fructose into HMF, which is further stabilized by LiCl and i-PrOH through the formation of hydrogen bonds and coordination bonds, 13,32,[45][46][47][48][49] affording satisfactory yield of HMF.…”

The research progress on CO&lt;sub&gt;2&lt;/sub&gt; absorption and conversion by metal coordination-based (chelate-based) ionic liquids

“…此外, 被吸收的CO 2 可以在氮气气氛中 实现解析, 金属螯合阳离子型ILs可以重复吸收CO 2 . 上 述实验结果引起了人们的兴趣, 李浩然课题组 [30] 借助 , 但上述金属阳离子螯合型ILs的阴离子…”

The interactions of chelate-based ionic liquids: from the perspective of vaporization enthalpy

“…Ionic liquids (ILs), molten salts (the melting points are usually well below 100 1C) composed of anions and cations, have adjustable physiochemical properties, and thereby can be synthesized task-specific 1 for applications in various fields. [2][3][4][5] Chelatebased ionic liquids (ChILs), 6,7 a kind of chelates with low melting points, have great potential in applications such as absorption, 8,9 separation, 10 electrochemistry, 11 photoelectromagnetics 12,13 and catalysis. 6,14 Thus, they attracted significant interest since their discovery.…”