The structure of ionic liquids (ILs) with shorter alkyl tail(s) of the constituent ions is predominantly governed by strong electrostatic interactions which are, in most cases, accompanied by specific interactions such as hydrogen bonding. Neat 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide $\left({\text{Im}}_{1,4}^{+}/{\text{NTf}}_2^{-}\right)$ IL possesses both of these interactions. However, in many conventional solvents such as short tail length primary alcohols, the structure is primarily determined by hydrogen bonding interactions. In this study, we aim to understand how the structure of ${\text{Im}}_{1,4}^{+}/{\text{NTf}}_2^{-}$ changes with the addition of different amount of alcohol by employing atomistic molecular dynamics simulations. Specifically, we have chosen ${\text{Im}}_{1,4}^{+}/{\text{NTf}}_2^{-}$ + 1-propanol and ${\text{Im}}_{1,4}^{+}/{\text{NTf}}_2^{-}$ + 1-butanol mixtures as the pure components of both the mixtures possess complex interactions, including hydrogen bonding. The mixtures’ composition-dependent structures were examined through simulated X-ray scattering structure functions (S(q)s), their partial components along with radial and spatial distribution functions. It is observed that there is significant hydrogen bonding between the anion and alcohols along with strong electrostatic interactions between the cation head and anion. For the entire composition of the mixtures studied, while alcohol’s hydroxyl group is found near the cation head and the anion’s oxygen atoms, the nonpolar tail of alcohol molecules tend to align with the tails of either the cation or other alcohol molecules. It is interesting to note that on adding even small amount of the IL (10%) to alcohol, low q peak observed for the neat alcohols disappears. The X-ray scattering S(q)s reveal that the long-range charge ordering structure of the ${\text{Im}}_{1,4}^{+}/{\text{NTf}}_2^{-}$ IL begin to build up at x_IL = 0.3 but at larger length scales. The transitional structural changes in the both the mixtures take place for 0.3 ≤ x_IL ≤ 0.8. The neat IL structure is virtually regained at and above x_IL = 0.8.

组成离子具有较短烷基尾的离子液体（IL）的结构主要受强静电相互作用的控制，在大多数情况下，静电相互作用会伴随特定的相互作用，例如氢键。干净的1-丁基-3-甲基咪唑双（三氟甲基磺酰基）酰亚胺$\left({\text{我是}}_{\mathrm{1个}，4}^{+}/{\text{NTf}}_{\mathrm{2个}}^{-}\right)$IL拥有这两种相互作用。但是，在许多常规溶剂中，例如短尾巴长度的伯醇，其结构主要由氢键相互作用决定。在这项研究中，我们旨在了解${\text{我是}}_{\mathrm{1个}，4}^{+}/{\text{NTf}}_{\mathrm{2个}}^{-}$通过采用原子分子动力学模拟，可以通过添加不同量的酒精来改变这种变化。具体来说，我们选择了${\text{我是}}_{\mathrm{1个}，4}^{+}/{\text{NTf}}_{\mathrm{2个}}^{-}$ + 1-丙醇和 ${\text{我是}}_{\mathrm{1个}，4}^{+}/{\text{NTf}}_{\mathrm{2个}}^{-}$作为两种混合物的纯组分的+ 1-丁醇混合物具有复杂的相互作用，包括氢键。通过模拟X射线散射结构函数（S（q）s），混合物的部分成分以及径向和空间分布函数，检查了混合物的成分相关结构。观察到，在阴离子和醇之间存在显着的氢键结合，并且在阳离子头和阴离子之间存在强的静电相互作用。对于所研究混合物的整个组成，虽然在阳离子头和阴离子的氧原子附近发现了醇的羟基，但醇分子的非极性尾巴倾向于与阳离子或其他醇分子的尾巴对齐。有趣的是，在酒精中加入少量IL（10％）后，观察到的纯醇的低q峰消失了。X射线散射S（q）s表明该分子的长程电荷有序结构${\text{我是}}_{\mathrm{1个}，4}^{+}/{\text{NTf}}_{\mathrm{2个}}^{-}$IL在x _IL  = 0.3时开始建立，但长度范围更大。在这两种混合物中的过渡结构的变化发生于0.3≤ X _IL ≤0.8。净的IL结构实际上在x _IL  = 0.8或更高时恢复。