Ionisationskonstanten von 1, 2, 4‐Triazolen [1]

Kröger, G.‐F.; Freiberg, W.

doi:10.1002/zfch.19650051012

Cited by 42 publications

(6 citation statements)

References 11 publications

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“…The pK a value of carboxylic groups is 3.32 ± 0.10, which is close to both pK a value of benzoic acid (4.17) and phthalic acid (2.98 and pK a 2 = 5.28). 39,40 By taking these pK a values into consideration, it can be concluded that sulfonic acid groups have higher acidity comparing to carboxylic groups.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…The pK a values of conjugated acids of these heterocycles are 7.05 and 2.27, respectively. 40,41 In the ideal case, the proton transfer from the acid to the base is complete, such that the only individual species present are the resulting cations and anions. However, for large counterions this is unlikely since the proton transfer may be less than complete, resulting in the neutral acid and base species being present, and therefore aggregation and association of either ions or neutral species can occur.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…With respect to nitrogen-containing heterocycles used in this study, the N -methyimidazole is more basic than the 1,2,4-1 H -triazole and is therefore a better proton acceptor. The p K a values of conjugated acids of these heterocycles are 7.05 and 2.27, respectively. , In the ideal case, the proton transfer from the acid to the base is complete, such that the only individual species present are the resulting cations and anions. However, for large counterions this is unlikely since the proton transfer may be less than complete, resulting in the neutral acid and base species being present, and therefore aggregation and association of either ions or neutral species can occur. , This feature should be taken into account when considering the dissociation of ionic groups of the proposed HBP-ILs.…”

Section: Results and Discussionmentioning

confidence: 99%

“…According to the evaluation with ACD/Laboratories program, the p K a value of sulfonic acid group is −1.09 ± 0.15, which is in good agreement with p K a values of structurally similar benzenesulfonic and p -toluenesulfonic acid (−2.8 and −1.3). The p K a value of carboxylic groups is 3.32 ± 0.10, which is close to both p K a value of benzoic acid (4.17) and phthalic acid (2.98 and p K a 2 = 5.28). , By taking these p K a values into consideration, it can be concluded that sulfonic acid groups have higher acidity comparing to carboxylic groups.…”

Section: General Discussion and Conclusionmentioning

confidence: 99%

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Assembly of Amphiphilic Hyperbranched Polymeric Ionic Liquids in Aqueous Media at Different pH and Ionic Strength

et al. 2016

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We demonstrated the assembly of amphiphilic hyperbranched protic ionic liquids (HBP-ILs) based on aliphatic hyperbranched polyester (HBP) in aqueous media in a wide range of pH and ionic conditions. The series of new branched polyionic liquids with different terminal groups, HBP-ILs, was synthesized by neutralization of carboxylic and sulfonic terminal acid groups of hypebranched core with N-methylimidazole (Im) and 1,2,4-1H-triazole (Tr). HBP-IL compounds with triazole and imidazole counterions form 12–16 nm core–corona micelles at pH 11.6. We found that the introduction of long hydrophobic terminal groups such as n-octadecylurethane tails to initial hydrophobic HBP core has larger effect on the size of micellar assemblies than the introduction of ionic terminals groups. Furthermore, tuning the hydrophilic/hydrophobic balance of HBP-ILs can be achieved by changing the degree of ionization of terminal groups and counterions by reducing pH from 11.6 to 5.2 or ionic strength to 0.1 M. These changes caused the formation of much larger micellar aggregates with the size of 150–200 nm due to reduced ionization of carboxylic groups. At the same time, for sulfonate-containing HBP-ILs the micelle size increased modestly (to 25–40 nm) because of the higher degree of ionization of sulfonate terminal groups. The diverse aggregation behavior of these branched polymeric ionic liquids enables control over their micellar morphologies in solution and bulk states.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

Section: General Discussion and Conclusionmentioning

confidence: 99%

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Assembly of Amphiphilic Hyperbranched Polymeric Ionic Liquids in Aqueous Media at Different pH and Ionic Strength

et al. 2016

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“…An aqueous solution of 6.6 mM DAT and Cu(OTf) 2 in water or 0.1 M NaClO 4 has a pH of 4.8 due to the formation of the Cu(DAT) complex. Upon protonation of the ligand (p K a of HDAT + is 4.4), 46 – 48 the Cu 2 (μ-DAT) 2 core is disrupted (Fig. S3, ESI † ).…”

Section: Resultsmentioning

confidence: 99%