Logo Beilstein Institut

Synthesis and physical properties of tunable aryl alkyl ionic liquids based on 1-aryl-4,5-dimethylimidazolium cations

  1. and
  2. ORCID Logo
Physikalische Organische Chemie, Technische Universität Dresden, 01062 Dresden, Germany
  1. Corresponding author email
Associate Editor: C. Stephenson
Beilstein J. Org. Chem. 2024, 20, 1278–1285. https://doi.org/10.3762/bjoc.20.110
Received 04 Mar 2024, Accepted 16 May 2024, Published 31 May 2024
Full Research Paper
cc by logo
PDF
Album
Supp Info
Cite

Abstract

We present a new class of tunable aryl alkyl ionic liquids (TAAILs) based on 1-aryl-4,5-dimethylimidazolium cations with electron-withdrawing and -donating substituents in different positions of the phenyl ring and the bis(trifluoromethylsulfonyl)imide (NTf2) anion. We investigated the effect of additional methyl groups in the backbone of the imidazolium core on the physical properties regarding viscosity, conductivity and electrochemical window. With an electrochemical window of up to 6.3 V, which is unprecedented for TAAILs with an NTf2 anion, this new class of TAAILs demonstrates the opportunities that arise from modifications in the backbone of the imidazolium cation.

Keywords: conductivity; electrochemical window; ionic liquids; tunable aryl alkyl ionic liquid; viscosity

Introduction

Ionic liquids (ILs) are a special class of solvents generally defined as salts with melting points below 100 °C [1]. Due to their unique properties, e.g., their high thermal stability and their negligible vapor pressure [2,3], ILs have found widespread use in different fields of chemistry like synthesis [4-9], catalysis [10-14] and materials science [15-23]. ILs generally consist of an organic cation [24], such as the imidazolium or ammonium ion and an inorganic anion like a halide anion or weakly coordinating anions like bis(trifluoromethylsulfonyl)imide [NTf2]− [25]. In addition, dicationic salts or anions containing metal complexes have been described [26,27]. Due to the numerous combinations of different anions and cations, ILs can also be described as designer solvents [28]. We introduced a new class of ionic liquids based on the 1-aryl-3-alkylimidazolium cation in 2009, the tunable aryl alkyl ionic liquids (TAAILs) [29]. This class of ionic liquids allows the modification of physical and chemical properties by variation of the functional groups present at the aryl ring of the ionic liquid in addition to the possibility to introduce alkyl chains with varying length [30]. TAAILs have already been successfully used for the synthesis of nanoparticles and as solvents in catalysis [31,32]. Recently we have described the synthesis and physical properties of TAAILs which have been blocked at the C2 position [33]. The use of a substituent at the C2 position was found to have a strong influence on the properties of these ionic liquids due to changes in the hydrogen-bonding network. Here, we investigate the properties of TAAILs based on the 1-aryl-4,5-dimethylimidazolium cation. It is well known that the hydrogen atom at the C2 carbon atom of the imidazole core is more acidic as those in the C4/C5-position, where the methyl groups are expected to also have a significant effect on the molecular interactions. Platinum complexes using the 4,5-dimethylimidazole motif as a ligand were already reported by our group [34] and piqued our interest on the performance of TAAILs based on this motif. Since the introduction of methyl groups in the backbone of the imidazolium core increases the stability and basicity of the corresponding imidazolium derivatives [35-37], we wanted to investigate the impact on the properties of ILs. The negative impact on viscosity and conductivity due to the higher mass should be comparatively low. We investigated different substituents with electron-donating as well as electron-withdrawing properties at the aryl ring and the difference between the ortho and para position of the substituent on the properties of the IL. For the [NTf2]− salts of the TAAILs, the viscosity, conductivity and the electrochemical window were determined.

Results and Discussion

In this work we focused on a synthetic strategy with cost efficient starting materials and a good scalability [38-42]. The substituted imidazoles 1–9 were synthesized using a condensation reaction between the corresponding aniline and diacetyl monoxime (Scheme 1), since the condensation using diacetyl was not successful for electron-poor aniline derivatives.

[1860-5397-20-110-i1]

Scheme 1: Overview of the synthesis of compounds 1–63.

This reaction leads to the formation of N-oxides, which were then reduced using iron powder. The imidazoles were synthesized in a one-pot procedure on a scale of up to 400 mmol. Quaternization of the imidazoles using bromoalkanes with different chain lengths provided the bromide salts 10–36. Conversion to the NTf2 ionic liquids 37–63 was achieved via anion exchange using LiNTf2.

The synthesized TAAILs with the NTf2 anion are all ionic liquids with a melting point well below 100 °C and the majority of these ILs can also be described as room temperature ionic liquids (RTIL), with a melting point below room temperature. The short-term thermal stability was investigated using ramped temperature analysis. The thermal decomposition temperatures (Table 1) for the ILs with the NTf2 anion are in the range from 266 °C (IL 59) to 409 °C (IL 37). In general, most ionic liquids with a butyl chain show higher decomposition temperatures than their counterparts with octyl or dodecyl chain. An increase in alkyl chain length from octyl to dodecyl, however, does not necessarily lead to a lower thermal stability.

Table 1: Thermal decomposition point at 5% mass loss in °C for NTf2− TAAILs 37–63 with different aryl substituents (R) and alkyl chain lengths (n).

R n = 4 n = 8 n = 12
H 409 298 322
4-Me 396 349 316
4-OMe 300 306 363
4-Br 378 397 350
4-CF3 393 313 378
4-OCF3 383 370 307
2-Me 323 322 339
2-OMe 372 266 343
2,4-F2 398 364 291

With decomposition temperatures of up to 409 °C (IL 37), the 1-aryl-4,5-dimethyl TAAILs can be described as ILs with a comparatively high thermal stability [43-45].

The viscosities of TAAILs with different aryl substitutions and a butyl chain are shown in Figure 1.

[1860-5397-20-110-1]

Figure 1: Temperature-dependent viscosity measurement of NTf2− TAAILs 37–63 with a butyl chain and different aryl substitution R.

At 25 °C the highest measured viscosity was 1675 cP for the TAAIL with the 4-Br substitution and the lowest viscosity (521 cP) for the TAAIL with the unsubstituted aryl moiety. The viscosities of the 4-CF3 and 2,4-F2 TAAILs with butyl chains are very similar, since the viscosity is influenced by π–π and dispersion effects facilitated by the electron-withdrawing effect of the fluorine atoms [46,47]. The 4-OCF3 substituted TAAIL with a butyl chain, however, displayed a much lower viscosity, indicating that additional steric effects due to the 4-OCF3 substituent play a role for the viscosity of the TAAIL [48,49]. The viscosities of the NTf2 ionic liquids 37–63 at 25 °C are given in Table 2. In general, with increasing alkyl chain lengths we observe an increasing viscosity of the TAAILs, which can be explained by the increase in molar mass and stronger van-der-Waals interactions. The only exceptions are the methoxy and 2,4-difluoro substituted TAAILs, demonstrating that the effects of the aryl substitution can have a stronger influence on the viscosity than the alkyl chain length.

Table 2: Viscosity in centipoise (cP) of NTf2− TAAILs 37–63 with different aryl substituents (R) and alkyl chain lengths (n), measured at 25 °C.

R n = 4 n = 8 n = 12
H 521 570 683
4-Me 652 750 762
4-OMe 970 900 1020
4-Br 1675 1720 solid
4-CF3 1003 1092 solid
4-OCF3 566 638 solid
2-Me 755 835 919
2-OMe 1140 1134 1268
2,4-F2 971 891 1016

The conductivity of the unsubstituted TAAIL 37 with 319 μS cm−1 is the highest among the investigated 4,5-dimethylimidazolium based TAAILs (Figure 2, Table 3). This is supported by the corresponding observation that TAAIL 37 also shows the lowest viscosity. As a result of their high viscosity, the 4-Br substituted TAAILs 46 and 47 display the lowest conductivities (96 and 62 μS cm−1, respectively).

[1860-5397-20-110-2]

Figure 2: Conductivity of NTf2− TAAILs 37–63 measured at 25 °C. Compounds 48, 51, and 54 are excluded because of their melting point.

To visualize the correlation between conductivity and viscosity, the conductivity is plotted against the viscosity in Figure 3. The 4-OCF3 substituted TAAIL 52 shows a similar viscosity to TAAIL 37, the conductivity, however, is much lower (198 μS cm−1), demonstrating the influence of the perfluorinated 4-OCF3 group on the conductivity.

[1860-5397-20-110-3]

Figure 3: Conductivity of NTf2− TAAILs with a butyl chain plotted against their viscosity at 25 °C.

Changing the position of the methyl and methoxy substituent from ortho to para leads to an increase in conductivity. Overall, longer alkyl chains lead to a decreasing conductivity, with the difference between butyl and octyl being more drastic than the difference between octyl and dodecyl.

To determine the electrochemical stability of the TAAILs, their electrochemical properties were investigated using linear sweep voltammetry (LSV, Figure 4). The setup consisted of a glassy carbon working electrode, a platinum wire counter electrode and a silver wire as reference electrode. The cutoff at which the cathodic limit Ered and the anodic limit Eox were determined was −0.1 and 0.1 mA cm−2. The electro-chemical window EEW is determined from the difference between Ered and Eox.

[1860-5397-20-110-4]

Figure 4: Linear sweep voltammetry of NTf2− TAAILs with a butyl chain and different aryl substituents R. Black lines indicate cutoff. Scan rate: 50 mV s−1. Scan start at 0 V.

The anodic limit Eox is mainly influenced by the anion of the ionic liquid, resulting in similar values for Eox for the NTf2-based TAAILs. The cathodic limit Ered depends on the cation and at what voltage the imidazolium cation is reduced. The substitution on the aryl ring has a strong influence on the reductive potential (Ered), ranging from −0.7 V for the 4-CF3 substituted TAAIL 49 to −2.6 V for the 2-Me substituted TAAIL 55 with a butyl chain. The change from ortho to para substitution led to a decrease of the cathodic limit in case of the methyl and methoxy-substituted TAAILs. The majority of TAAILs with a butyl chain have a cathodic limit between −1.0 and −2.0 V. The electrochemical window for the TAAILs with a butyl chain ranges from 2.4 V to 4.4 V. In general, an increase of the alkyl chain length leads to a wider electrochemical window. The results of the electrochemical measurements of all TAAILs can be found in Table 3, with the largest electrochemical window being 6.3 V for TAAIL 57. This is the largest electrochemical window reported for TAAILs with NTf2 anion so far [50-53]. The size of the electrochemical window, however, depends heavily on the measurement conditions, preventing a general comparison with previously reported electrochemical windows [54,55]. The plots of all LSV measurements can be found in Supporting Information File 1 (Figures S1–S8).

Table 3: Physicochemical data of NTf2− TAAILs 37–63. R: aryl substituent, n: alkyl chain length. Specific conductivity σ was measured at 25 °C. Anodic and cathodic cut-off limit: 0.1 mA cm−2. 48, 51 and 54 are excluded due to their melting point.

Nr R n σ
[μS cm−1] 		Ered
[V] 		Eox
[V] 		EEW
[V]
37 H 4 319 −1.7 1.5 3.2
38 H 8 150 −2.0 1.6 3.6
39 H 12 120 −2.6 2.2 4.8
40 4-Me 4 206 −1.1 1.3 2.4
41 4-Me 8 133 −2.0 1.5 3.5
42 4-Me 12 102 −2.5 2.0 4.5
43 4-OMe 4 179 −1.8 1.2 3.0
44 4-OMe 8 115 −2.2 1.5 3.7
45 4-OMe 12 76 −3.0 1.7 4.7
46 4-Br 4 96 –a –a –a
47 4-Br 8 62 –a –a –a
49 4-CF3 4 127 −0.7 2.0 2.7
50 4-CF3 8 74 −2.9 2.3 5.2
52 4-OCF3 4 198 −1.2 1.6 2.8
53 4-OCF3 8 108 −2.9 2.6 5.5
55 2-Me 4 178 −2.6 1.8 4.4
56 2-Me 8 92 −2.7 2.2 4.9
57 2-Me 12 56 −3.4 2.9 6.3
58 2-OMe 4 133 −2.2 1.6 3.8
59 2-OMe 8 97 −2.7 1.9 4.6
60 2-OMe 12 42 −2.8 2.2 5.0
61 2,4-F2 4 137 −1.4 1.0 2.4
62 2,4-F2 8 87 −1.9 1.9 3.8
63 2,4-F2 12 51 −2.4 2.1 4.5

aNo results due to decomposition.

Figure 5 shows the molecular electrostatic potential (MEP) of the unsubstituted TAAIL cation [PhImC4H9]+, the unsubstituted 4,5-dimethyl-1-phenyl cation of TAAIL 37 and the cations of TAAILs 40 (4-CH3) and 49 (4-CF3).

[1860-5397-20-110-5]

Figure 5: Structures of the imidazolium cations obtained by DFT calculations (B3LYP/6-311++G (d,p)). The electrostatic potentials are indicated by color (blue: positive; red: negative).

The structures of the cations were optimized with Gaussian 16 [56], using the hybrid functional Becke3LYP [57-60] with the split valence triple-ζ basis set 6-311++G(d,p) [61-63] and D3 dispersion correction with the Becke–Johnson damping scheme [64,65]. All optimized structures were confirmed to be true minima by the absence of negative frequencies after harmonic vibrational modes calculation. The MEP was visualized with GaussView6. Comparing the 4,5-dimethylimidazolium cations 37, 40 and 49 with the previously reported TAAIL cation [PhImC4H9]+ shows that the methyl groups in the backbone of the imidazolium cation lead to a different electrostatic potential (Figure 4). Comparison of the 4-Me substituted imidazolium cation 40 with the 4-CF3 substituted cation 49 shows the influence of the electronegative fluorine atoms on the electrostatic potential of the cation.

Conclusion

Based on the synthesis of nine different 1-aryl-4,5-dimethyl substituted imidazoles we report a new class of ionic liquids with electron-donating and -withdrawing substituents, three different alkyl chain lengths and bromide as well as NTf2 anions. The physicochemical properties (thermal properties, viscosity, conductivity and electrochemical window) of the RTILs were investigated. The two methyl groups in the backbone of the imidazolium core lead to a slightly higher viscosity compared to the unsubstituted congeners. It is also influenced by the type of substitution (electron-withdrawing or -donating) at the aryl ring as well as the alkyl chain length. By introducing the methyl groups in the backbone of the imidazolium cation we were able to enlarge the electrochemical window up to 6.3 V, which is currently the largest window for a bis(trifluoromethylsulfonyl)imide tunable aryl alkyl ionic liquid.

Supporting Information

Supporting Information File 1: Experimental procedures and characterization data.
Format: PDF Size: 10.0 MB Download

Acknowledgements

The authors thank the ZIH Dresden for the generous allocation of compute time at their high-performance computing facility.

Data Availability Statement

All data that supports the findings of this study is available in the published article and/or the supporting information to this article.

References

  1. Lei, Z.; Chen, B.; Koo, Y.-M.; MacFarlane, D. R. Chem. Rev. 2017, 117, 6633–6635. doi:10.1021/acs.chemrev.7b00246
    Return to citation in text: [1]
  2. Brennecke, J. F.; Maginn, E. J. AIChE J. 2001, 47, 2384–2389. doi:10.1002/aic.690471102
    Return to citation in text: [1]
  3. Wang, B.; Qin, L.; Mu, T.; Xue, Z.; Gao, G. Chem. Rev. 2017, 117, 7113–7131. doi:10.1021/acs.chemrev.6b00594
    Return to citation in text: [1]
  4. Plechkova, N. V.; Seddon, K. R. Chem. Soc. Rev. 2008, 37, 123–150. doi:10.1039/b006677j
    Return to citation in text: [1]
  5. Hallett, J. P.; Welton, T. Chem. Rev. 2011, 111, 3508–3576. doi:10.1021/cr1003248
    Return to citation in text: [1]
  6. Ashraf, R.; Khalid, Z.; Sarfraz, A.; Bhatti, H. N.; Iqbal, M. A.; Nazari V, M. J. Mol. Struct. 2021, 1241, 130701. doi:10.1016/j.molstruc.2021.130701
    Return to citation in text: [1]
  7. Ghirardello, M.; Costantini, M.; Vecchi, A.; Pacifico, S.; Pazzi, D.; Castiglione, F.; Mele, A.; Marra, A. Eur. J. Org. Chem. 2022, e202200100. doi:10.1002/ejoc.202200100
    Return to citation in text: [1]
  8. Meeniga, I.; Gokanapalli, A.; Peddiahgari, V. G. R. Sustainable Chem. Pharm. 2022, 30, 100874. doi:10.1016/j.scp.2022.100874
    Return to citation in text: [1]
  9. Zunita, M.; Wahyuningrum, D.; Buchari; Bundjali, B.; Gede Wenten, I.; Boopathy, R. Bioresour. Technol. 2020, 315, 123864. doi:10.1016/j.biortech.2020.123864
    Return to citation in text: [1]
  10. Pârvulescu, V. I.; Hardacre, C. Chem. Rev. 2007, 107, 2615–2665. doi:10.1021/cr050948h
    Return to citation in text: [1]
  11. Dupont, J.; Kollár, L., Eds. Ionic Liquids (ILs) in Organometallic Catalysis; Topics in Organometallic Chemistry; Springer Berlin: Berlin, Germany, 2015. doi:10.1007/978-3-662-47857-8
    Return to citation in text: [1]
  12. Wasserscheid, P.; Keim, W. Angew. Chem., Int. Ed. 2000, 39, 3772–3789. doi:10.1002/1521-3773(20001103)39:21<3772::aid-anie3772>3.0.co;2-5
    Return to citation in text: [1]
  13. Kumar, S.; Rastogi, S. K.; Singh, A.; Bharati Ahirwar, M.; Deshmukh, M. M.; Sinha, A. K.; Kumar, R. Asian J. Org. Chem. 2022, 11, e202100749. doi:10.1002/ajoc.202100749
    Return to citation in text: [1]
  14. Tay, B.; van Meurs, M.; Tan, J.; Ye, S.; Borgna, A.; van Herk, A. M.; Selvaratnam, S.; Wang, C.; Taniguchi, S.; Suzuki, Y.; Utsunomiya, M.; Ito, M.; Monden, T.; Shibata, H.; Tomita, S. Ind. Eng. Chem. Res. 2021, 60, 17928–17941. doi:10.1021/acs.iecr.1c03822
    Return to citation in text: [1]
  15. Galiński, M.; Lewandowski, A.; Stępniak, I. Electrochim. Acta 2006, 51, 5567–5580. doi:10.1016/j.electacta.2006.03.016
    Return to citation in text: [1]
  16. Armand, M.; Endres, F.; MacFarlane, D. R.; Ohno, H.; Scrosati, B. Nat. Mater. 2009, 8, 621–629. doi:10.1038/nmat2448
    Return to citation in text: [1]
  17. Drücker, P.; Rühling, A.; Grill, D.; Wang, D.; Draeger, A.; Gerke, V.; Glorius, F.; Galla, H.-J. Langmuir 2017, 33, 1333–1342. doi:10.1021/acs.langmuir.6b03182
    Return to citation in text: [1]
  18. Ghaed-Sharaf, T.; Ghatee, M. H. J. Mol. Liq. 2021, 332, 115874. doi:10.1016/j.molliq.2021.115874
    Return to citation in text: [1]
  19. Liwarska-Bizukojc, E.; Maton, C.; Stevens, C. V.; Gendaszewska, D. J. Chem. Technol. Biotechnol. 2014, 89, 763–768. doi:10.1002/jctb.4187
    Return to citation in text: [1]
  20. Min, Z.; Chang, B.; Shao, C.; Su, X.; Wang, N.; Li, Z.; Wang, H.; Zhao, Y.; Fan, M.; Wang, J. Appl. Catal., B 2023, 326, 122185. doi:10.1016/j.apcatb.2022.122185
    Return to citation in text: [1]
  21. Starling, P. D. J.; Metilda, P. J. Mol. Struct. 2022, 1251, 132062. doi:10.1016/j.molstruc.2021.132062
    Return to citation in text: [1]
  22. Yang, Y.; Zhou, H.; Xiao, Y.; Feng, L.; Yang, L.; Mu, W.; Peng, X.; Bao, L.; Wang, J. Carbohydr. Polym. 2021, 255, 117363. doi:10.1016/j.carbpol.2020.117363
    Return to citation in text: [1]
  23. Prete, D.; Dimaggio, E.; Demontis, V.; Zannier, V.; RodriguezDouton, M. J.; Guazzelli, L.; Beltram, F.; Sorba, L.; Pennelli, G.; Rossella, F. Adv. Funct. Mater. 2021, 31, 2104175. doi:10.1002/adfm.202104175
    Return to citation in text: [1]
  24. Vekariya, R. L. J. Mol. Liq. 2017, 227, 44–60. doi:10.1016/j.molliq.2016.11.123
    Return to citation in text: [1]
  25. Krossing, I.; Raabe, I. Angew. Chem., Int. Ed. 2004, 43, 2066–2090. doi:10.1002/anie.200300620
    Return to citation in text: [1]
  26. Mezzetta, A.; Guglielmero, L.; Mero, A.; Tofani, G.; D’Andrea, F.; Pomelli, C. S.; Guazzelli, L. Molecules 2021, 26, 4211. doi:10.3390/molecules26144211
    Return to citation in text: [1]
  27. Guglielmero, L.; Mero, A.; Mezzetta, A.; Tofani, G.; D'Andrea, F.; Pomelli, C. S.; Guazzelli, L. J. Mol. Liq. 2021, 340, 117210. doi:10.1016/j.molliq.2021.117210
    Return to citation in text: [1]
  28. Earle, M. J.; Seddon, K. R. Pure Appl. Chem. 2000, 72, 1391–1398. doi:10.1351/pac200072071391
    Return to citation in text: [1]
  29. Ahrens, S.; Peritz, A.; Strassner, T. Angew. Chem., Int. Ed. 2009, 48, 7908–7910. doi:10.1002/anie.200903399
    Return to citation in text: [1]
  30. Lerch, S.; Strassner, T. Chem. – Eur. J. 2021, 27, 15554–15557. doi:10.1002/chem.202102545
    Return to citation in text: [1]
  31. Woitassek, D.; Strothmann, T.; Biller, H.; Lerch, S.; Schmitz, H.; Song, Y.; Roitsch, S.; Strassner, T.; Janiak, C. Molecules 2023, 28, 405. doi:10.3390/molecules28010405
    Return to citation in text: [1]
  32. Schroeter, F.; Lerch, S.; Kaliner, M.; Strassner, T. Org. Lett. 2018, 20, 6215–6219. doi:10.1021/acs.orglett.8b02688
    Return to citation in text: [1]
  33. Biller, H.; Strassner, T. Chem. – Eur. J. 2023, 29, e202202795. doi:10.1002/chem.202202795
    Return to citation in text: [1]
  34. Stipurin, S.; Strassner, T. J. Organomet. Chem. 2023, 1000, 122785. doi:10.1016/j.jorganchem.2023.122785
    Return to citation in text: [1]
  35. Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267. doi:10.1039/c39950001267
    Return to citation in text: [1]
  36. Kuhn, N.; Steimann, M.; Weyers, G. Z. Naturforsch., B: J. Chem. Sci. 1999, 54, 427–433. doi:10.1515/znb-1999-0401
    Return to citation in text: [1]
  37. Kunetskiy, R. A.; Císařová, I.; Šaman, D.; Lyapkalo, I. M. Chem. – Eur. J. 2009, 15, 9477–9485. doi:10.1002/chem.200901203
    Return to citation in text: [1]
  38. Shabalin, D. A.; Camp, J. E. Org. Biomol. Chem. 2020, 18, 3950–3964. doi:10.1039/d0ob00350f
    Return to citation in text: [1]
  39. Patel, G.; Dewangan, D. K.; Bhakat, N.; Banerjee, S. Curr. Res. Green Sustainable Chem. 2021, 4, 100175. doi:10.1016/j.crgsc.2021.100175
    Return to citation in text: [1]
  40. Mityanov, V. S.; Perevalov, V. P.; Tkach, I. I. Chem. Heterocycl. Compd. 2013, 48, 1793–1800. doi:10.1007/s10593-013-1210-8
    Return to citation in text: [1]
  41. Koutsoukos, S.; Becker, J.; Dobre, A.; Fan, Z.; Othman, F.; Philippi, F.; Smith, G. J.; Welton, T. Nat. Rev. Methods Primers 2022, 2, 49. doi:10.1038/s43586-022-00129-3
    Return to citation in text: [1]
  42. Matthews, R. P.; Welton, T.; Hunt, P. A. Phys. Chem. Chem. Phys. 2014, 16, 3238–3253. doi:10.1039/c3cp54672a
    Return to citation in text: [1]
  43. Cao, Y.; Mu, T. Ind. Eng. Chem. Res. 2014, 53, 8651–8664. doi:10.1021/ie5009597
    Return to citation in text: [1]
  44. Maton, C.; De Vos, N.; Stevens, C. V. Chem. Soc. Rev. 2013, 42, 5963–5977. doi:10.1039/c3cs60071h
    Return to citation in text: [1]
  45. Yu, G.; Zhao, D.; Wen, L.; Yang, S.; Chen, X. AIChE J. 2012, 58, 2885–2899. doi:10.1002/aic.12786
    Return to citation in text: [1]
  46. Böhm, H.-J.; Banner, D.; Bendels, S.; Kansy, M.; Kuhn, B.; Müller, K.; Obst‐Sander, U.; Stahl, M. ChemBioChem 2004, 5, 637–643. doi:10.1002/cbic.200301023
    Return to citation in text: [1]
  47. Leroux, F. R.; Manteau, B.; Vors, J.-P.; Pazenok, S. Beilstein J. Org. Chem. 2008, 4, 13. doi:10.3762/bjoc.4.13
    Return to citation in text: [1]
  48. Klocker, J.; Karpfen, A.; Wolschann, P. Chem. Phys. Lett. 2003, 367, 566–575. doi:10.1016/s0009-2614(02)01786-4
    Return to citation in text: [1]
  49. Barrosse‐Antle, L. E.; Bond, A. M.; Compton, R. G.; O'Mahony, A. M.; Rogers, E. I.; Silvester, D. S. Chem. – Asian J. 2010, 5, 202–230. doi:10.1002/asia.200900191
    Return to citation in text: [1]
  50. Lane, G. H. Electrochim. Acta 2012, 83, 513–528. doi:10.1016/j.electacta.2012.08.046
    Return to citation in text: [1]
  51. De Vos, N.; Maton, C.; Stevens, C. V. ChemElectroChem 2014, 1, 1258–1270. doi:10.1002/celc.201402086
    Return to citation in text: [1]
  52. Doblinger, S.; Donati, T. J.; Silvester, D. S. J. Phys. Chem. C 2020, 124, 20309–20319. doi:10.1021/acs.jpcc.0c07012
    Return to citation in text: [1]
  53. Chen, Y.; Liu, S.; Bi, Z.; Li, Z.; Zhou, F.; Shi, R.; Mu, T. Green Energy Environ. 2024, 9, 966–991. doi:10.1016/j.gee.2023.05.002
    Return to citation in text: [1]
  54. Gancarz, P.; Zorębski, E.; Dzida, M. Electrochem. Commun. 2021, 130, 107107. doi:10.1016/j.elecom.2021.107107
    Return to citation in text: [1]
  55. Piatti, E.; Guglielmero, L.; Tofani, G.; Mezzetta, A.; Guazzelli, L.; D'Andrea, F.; Roddaro, S.; Pomelli, C. S. J. Mol. Liq. 2022, 364, 120001. doi:10.1016/j.molliq.2022.120001
    Return to citation in text: [1]
  56. Gaussian 16, Revision A.03; Gaussian, Inc.: Wallingford, CT, 2016.
    Return to citation in text: [1]
  57. Becke, A. D. J. Chem. Phys. 1993, 98, 5648–5652. doi:10.1063/1.464913
    Return to citation in text: [1]
  58. Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. B 1988, 37, 785–789. doi:10.1103/physrevb.37.785
    Return to citation in text: [1]
  59. Vosko, S. H.; Wilk, L.; Nusair, M. Can. J. Phys. 1980, 58, 1200–1211. doi:10.1139/p80-159
    Return to citation in text: [1]
  60. Stephens, P. J.; Devlin, F. J.; Chabalowski, C. F.; Frisch, M. J. J. Phys. Chem. 1994, 98, 11623–11627. doi:10.1021/j100096a001
    Return to citation in text: [1]
  61. Krishnan, R.; Binkley, J. S.; Seeger, R.; Pople, J. A. J. Chem. Phys. 1980, 72, 650–654. doi:10.1063/1.438955
    Return to citation in text: [1]
  62. Clark, T.; Chandrasekhar, J.; Spitznagel, G. W.; Schleyer, P. V. R. J. Comput. Chem. 1983, 4, 294–301. doi:10.1002/jcc.540040303
    Return to citation in text: [1]
  63. Frisch, M. J.; Pople, J. A.; Binkley, J. S. J. Chem. Phys. 1984, 80, 3265–3269. doi:10.1063/1.447079
    Return to citation in text: [1]
  64. Grimme, S.; Antony, J.; Ehrlich, S.; Krieg, H. J. Chem. Phys. 2010, 132, 154104. doi:10.1063/1.3382344
    Return to citation in text: [1]
  65. Grimme, S.; Ehrlich, S.; Goerigk, L. J. Comput. Chem. 2011, 32, 1456–1465. doi:10.1002/jcc.21759
    Return to citation in text: [1]

© 2024 Fritsch and Strassner; licensee Beilstein-Institut.
This is an open access article licensed under the terms of the Beilstein-Institut Open Access License Agreement (https://www.beilstein-journals.org/bjoc/terms), which is identical to the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0). The reuse of material under this license requires that the author(s), source and license are credited. Third-party material in this article could be subject to other licenses (typically indicated in the credit line), and in this case, users are required to obtain permission from the license holder to reuse the material.

Other Beilstein-Institut Open Science Activities
Journal Logo
Institut Logo
Preprint Logo
Symposia Logo