Addition/Correction pubs.acs.org/Langmuir
Correction to “Rational Design and Synthesis of Carboxylate Gemini Surfactants with an Excellent Aggregate Behavior for Nano-La2O3 Morphology-Controllable Preparation” Xueming Liao, Zhinong Gao,* Yan Xia, Fei Niu, and Wenzhong Zhai Langmuir 2017, 33, 3304−3310, doi: 10.1021/acs.langmuir.7b00096] 1. CORRECTION OF THE CHEMICAL REACTION EQUATIONS (SCHEME 1 IN THE PAPER) As for the gemini surfactants described in the original Article, the reaction of binary anhydride with long chain alkyl alcohol will generate three main isomers, but we failed to support the other two isomers in the paper in Scheme 1. Here we corrected it (Scheme S2-1). So, the products of the carboxylate gemini surfactants (CGS) are isomers coexisting in a composite system, rather than a single compound system, which is illustrated by the measurement below.
1.70−1.76 (m, 4 H), 3.35−3.48 (m, 4 H), 3.51−3.67 (m, 12 H), 7.45−8.85 (m,6H).
3. ADDITIONAL 13C NMR DATA OF CGS INTERMEDIATE (DADEK) In order to prove the existence of isomers in the system rather than of impurity in 1H NMR spectra, we decided to do an additional test of 13C NMR spectra (the main isomer will show three carbonyls if isomers really exist in the system). As can be seen from the 13C NMR of C12-ϕ-C12 intermediate, there are three peaks (194−195 ppm) of carbonyl from isomers, as we expected, but it shows that the peaks are very weak. One possible reason is that the existence of hydrogen bonds (intramolecular or intermolecular hydrogen bonds) in the isomer system caused displacement of carbonyl to move to the low field and weaken the peaks of carbonyl; the other reason is the effect of the diphenyl ketone conjugate structure. Moreover, we can see multiple carbonyl peaks (167.18, 167.32, 169.67, 170.42, 170.62, and 171.15 ppm) of three isomers from carboxyl groups and ester groups, which further illustrates that the isomers exist in the system too. Meanwhile, different peaks of carbon atom on the benzene ring are consistent with the benzene ring carbon atoms of these three isomers. Additionally, the other three kinds of 13C NMR data of CGS intermediates are the same as C12-ϕ-C12, and are shown in Figure S2-2.
2. ADDITIONAL 1H NMR DATA OF CGS We have once again analyzed the related experimental data (original data) and repeated the experiment. The result showed that the experiment can be repeated (Figure S2-1 shows the 1H NMR spectra of four kinds of CGS). As can be seen from the 1H NMR of CGS, all of the 1H NMR spectra showed six group peaks of H on the benzene ring region, rather than three, which suggested that isomers of CDS coexisted in the system. The three major isomers are shown in Scheme S2-1. (1) 1H NMR of C12-ϕ-C12, and the 1H NMR peaks are shown below: (300 MHz, CDCl3): δ 0.85−0.90 (t, 6 H), 1.20−1.34 (m, 36H), 1.46−1.51 (t, 18 H), 1.70−1.76 (m, 4 H), 3.35−3.48 (m, 4 H), 3.51−3.67 (m, 12 H), 7.45−8.85 (m,6H). (2) 1H NMR of C14-ϕ-C14: (300 MHz, CDCl3): δ 0.85−0.90 (t, 6 H), 1.20−1.34 (m, 44H), 1.46−1.51 (t, 18 H), 1.70−1.76 (m, 4 H), 3.35−3.48 (m, 4 H), 3.51−3.67 (m, 12 H), 7.45−8.85 (m,6H). (3) 1H NMR of C16-ϕ-C16: (300 MHz, CDCl3): δ 0.85−0.90 (t, 6 H), 1.20−1.34 (m, 52H), 1.46−1.51 (t, 18 H), 1.70−1.76 (m, 4 H), 3.35−3.48 (m, 4 H), 3.51−3.67 (m, 12 H), 7.45−8.85 (m,6H). (4) 1H NMR of C18-ϕ-C18: (300 MHz, CDCl3): δ 0.85−0.90 (t, 6 H), 1.20−1.34 (m, 60H), 1.46−1.51 (t, 18 H),
4. EXPLANATION OF ISOMERS BEING TREATED AS A WHOLE Gemini surfactants are also known as dimeric surfactants, which belong to oligomeric surfactants. According to the gemini surfactants described in the Article, we were aware that the reaction of binary anhydride with long-chain alkyl alcohol will generate isomers, but (1) they were still gemini surfactants, (2) they all obtained the same spacer group, hydrophilic
Scheme S2-1. Synthetic Route of CGS
Published: July 21, 2017 © 2017 American Chemical Society
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DOI: 10.1021/acs.langmuir.7b02112 Langmuir 2017, 33, 7588−7590
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Addition/Correction
Figure S2-1. 1H NMR of CGS.
head groups, and hydrophobic tail chains, and (3) they all had the same functional groups, such as carboxylic acid ammonium salt, ketone carbonyl, ester group, and so on. According to the principle of structure-determining performance, these isomers in the C12-ϕ-C12 system (same with C14-ϕ-C14, C16-ϕ-C16, and C18-ϕ-C18) have a lot in common, so it is more than reasonable for us to study them as a whole. We decided to study the integrated performance of the composite system, rather than to split them and study them separately (though we can clearly see the cis isomers from 1H NMR and 13C NMR spectra). Test results show that the isomer-coexisting system has very excellent surface active property, aggregation behavior, and works well as a template for morphology-controllable synthesis of nano-La2O3, which can be the result of isomers synergy. The results also show that isomers being treated as a whole is a feasible and effective research method.
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DOI: 10.1021/acs.langmuir.7b02112 Langmuir 2017, 33, 7588−7590
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Figure S2-2. 13C NMR of CGS intermediates.
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DOI: 10.1021/acs.langmuir.7b02112 Langmuir 2017, 33, 7588−7590
