This study is focused on the development of iridium(IV)-specific quaternary diammonium cations containing electron-donating and electron-withdrawing groups. Quaternary diammonium cations used were tetramethylbenzyl-1,10-diammonium decane chloride (QuatDMDAMeBnz), tetrabenzyl-1,10-diammonium decane chloride (QuatDMDABnz), tetratrifluoromethylbenzyl-1,10-diammonium chloride (QuatDMDACF3Bnz), and tetranitrobenzyl-1,10-diammonium chloride (QuatDMDANO2Bnz). Polyvinylbenzylchloride (PVBC) nanofibers were used as a support material, and the functionalised nanofibers were used for the separation of Ir(IV) from Rh(III). The efficiency of the quaternary diammonium cations was investigated in a column study under dynamic flow adsorption conditions. Column sorption of [IrCl₆]^2- and [RhCl₅(H₂O)]^2- on nanofibers functionalized with diammonium cations showed [RhCl₅(H₂O)]^2- was not adsorbed by the sorbent materials while [IrCl₆]^2- was loaded onto the column. The loading capacities of [IrCl₆]^2- on the quaternary diammonium sorbent materials increased in the order of F-QuatDMDAMeBnz (3.08 mg/g; 16.01 mmol/g) < F-QuatDMDABnz (3.39 mg/g; 17.63 mmol/g) < F-QuatDMDACF3Bnz (5.46 mg/g; 28.42 mmol/g) < F-QuatDMDANO2Bnz (7.10 mg/g; 36.96 mmol/g). The loading capacity for Ir(IV) with quaternary diammonium cationic nanofibers increased with an increase in the electron-withdrawing nature of the substituent on the quaternizing group. This trend was further explained by considering the anion binding energies and electrostatic charges of the diammonium cations as well as their ion-pairing interactions with [IrCl₆]^2- and [RhCl₅(H₂O)]^2- using molecular modeling calculations. The formation of [(L)IrCl₆] ion-pairs with the charge diffuse [IrCl₆]^2- anion was energetically favoured from QuatDMDAMeBnz to QuatDMDANO2Bnz. The positive electrostatic potential (ESP) values of 473.92 kcal/mol for QuatDMDAMeBnz, 495.85 kcal/mol for QuatDMDABnz, 991.12 kcal/mol for QuatDMDACF3Bnz and 1133.05 kcal/mol for QuatDMDANO2Bnz also followed this trend. This trend was also well correlated with binding energies of the respective cations with [IrCl₆]^2- which were 22.66 kcal/mol for QuatDMDAMeBnz, 27.43 kcal/mol for QuatDMDABnz, 49.19 kcal/mol for QuatDMDACF3Bnz and 51.04 kcal/mol for QuatDMDANO2Bnz.

本研究的重点是开发含有给电子和吸电子基团的铱 (IV) 特异性季铵阳离子。使用的季铵阳离子是四甲基苄基-1,10-二铵癸烷氯化物 (QuatDMDAMeBnz)、四苄基-1,10-二铵癸烷氯化物 (QuatDMDABnz)、四氟甲基苄基-1,10-二氯化铵 (QuatDMDACF3Bnz) 和四硝基苄基-1,10-氯化二铵 (QuatDMDANO2Bnz)。聚氯乙烯 (PVBC) 纳米纤维用作支撑材料，功能化的纳米纤维用于将 Ir(IV) 与 Rh(III) 分离。在动态流动吸附条件下的柱研究中研究了季铵阳离子的效率。_{[IrCl 6} ] ^2-和 [RhCl的柱吸附用二铵阳离子功能化的纳米纤维上的₅ (H ₂ O)] ^{2-表明 [RhCl} ₅ (H ₂ O)] ^2-没有被吸附剂材料吸附，而 [IrCl ₆ ] ^2-被加载到柱上。[IrCl ₆ ] ^{2-的负载能力}对季铵吸附剂材料的增加顺序为 F-QuatDMDAMeBnz (3.08 mg/g; 16.01 mmol/g) < F-QuatDMDABnz (3.39 mg/g; 17.63 mmol/g) < F-QuatDMDACF3Bnz (5.46 mg/g; 28.42 mmol/g) < F-QuatDMDANO2Bnz (7.10 mg/g; 36.96 mmol/g)。季铵盐阳离子纳米纤维对 Ir(IV) 的负载能力随着季铵化基团上取代基吸电子性质的增加而增加。通过使用分子模型计算考虑阴离子结合能和二铵阳离子的静电荷以及它们与 [IrCl ₆ ] ^2-和 [RhCl ₅ (H ₂ O)] ^{2-的离子配对相互作用，进一步解释了这一趋势。}[(L)IrCl _6的形成] 离子对与电荷扩散 [IrCl ₆ ] ^2-阴离子从 QuatDMDAMeBnz 到 QuatDMDANO2Bnz 受到大力支持。QuatDMDAMeBnz 的正静电势 (ESP) 值为 473.92 kcal/mol，QuatDMDABnz 为 495.85 kcal/mol，QuatDMDACF3Bnz 为 991.12 kcal/mol，QuatDMDANO2Bnz 为 1133.05 kcal/mol。这种趋势也与各个阳离子与 [IrCl ₆ ] ^2-的结合能密切相关，QuatDMDAMeBnz 为 22.66 kcal/mol，QuatDMDABnz 为 27.43 kcal/mol，QuatDMDACF3Bnz 为 49.19 kcal/mol，QuatDMDANO2Bnz 为 51.04 kcal/mol。