{"title":"Effect of the alkyl chain length of α,ω-dichloroalkane on the Gibbs energy of transfer for functional groups.","authors":"Kohei Uematsu, Erina Tanaka, Takanari Tanaka, Hajime Katano","doi":"10.1007/s44211-024-00656-x","DOIUrl":null,"url":null,"abstract":"<p><p>Ion-transfer reactions of alkyl and perfluoroalkyl carboxylate ions (CH<sub>3</sub>(CH<sub>2</sub>)<sub>n-2</sub>COO<sup>-</sup> with n = 8-12 and CF<sub>3</sub>(CF<sub>2</sub>)<sub>n-2</sub>COO<sup>-</sup> with n = 3-9) were investigated at the polarized Cl-(CH<sub>2</sub>)<sub>m</sub>-Cl with m = 2, 4, 6, and 8 (O) | water (W) interface to evaluate the effects of n and m on the solvation energy of the ions, as well as on their methylene and terminal groups. These ions exhibited reversible or quasi-reversible voltammetric waves due to their transfer across the O | W interfaces, enabling the determination of formal potentials and formal Gibbs transfer energies from O to W, <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> . The <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> values for CH<sub>3</sub>(CH<sub>2</sub>)<sub>n-2</sub>COO<sup>-</sup> and CF<sub>3</sub>(CF<sub>2</sub>)<sub>n-2</sub>COO<sup>-</sup> increased linearly with n, allowing the estimation of <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> for methylene and difluoromethylene groups, <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> (CH<sub>2</sub>) and <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> (CF<sub>2</sub>), and for their terminal groups, <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> (COO<sup>-</sup> + CH<sub>3</sub>) and <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> (COO<sup>-</sup> + CF<sub>3</sub>). Whereas the <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> (CH<sub>2</sub>) and <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> (CF<sub>2</sub>) hardly changed with the variation in m, the <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> (COO<sup>-</sup> + CH<sub>3</sub>) and <math><mrow><mi>Δ</mi> <msubsup><mi>G</mi> <mrow><mrow><mtext>tr,O</mtext> <mo>→</mo> <mtext>W</mtext></mrow> </mrow> <msup><mn>0</mn> <mo>'</mo></msup> </msubsup> </mrow> </math> (COO<sup>-</sup> + CF<sub>3</sub>) decreased noticeably. These results suggest that the solvation energy for ions in Cl-(CH<sub>2</sub>)<sub>m</sub>-Cl increases with m, regardless of hydrophilic or lipophilic nature of the ions. Based on these findings, the advantage of using Cl-(CH<sub>2</sub>)<sub>m</sub>-Cl with a large m as a non-aqueous solvent for ion-transfer voltammetry was discussed.</p>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Analytical Sciences","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1007/s44211-024-00656-x","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, ANALYTICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Ion-transfer reactions of alkyl and perfluoroalkyl carboxylate ions (CH3(CH2)n-2COO- with n = 8-12 and CF3(CF2)n-2COO- with n = 3-9) were investigated at the polarized Cl-(CH2)m-Cl with m = 2, 4, 6, and 8 (O) | water (W) interface to evaluate the effects of n and m on the solvation energy of the ions, as well as on their methylene and terminal groups. These ions exhibited reversible or quasi-reversible voltammetric waves due to their transfer across the O | W interfaces, enabling the determination of formal potentials and formal Gibbs transfer energies from O to W, . The values for CH3(CH2)n-2COO- and CF3(CF2)n-2COO- increased linearly with n, allowing the estimation of for methylene and difluoromethylene groups, (CH2) and (CF2), and for their terminal groups, (COO- + CH3) and (COO- + CF3). Whereas the (CH2) and (CF2) hardly changed with the variation in m, the (COO- + CH3) and (COO- + CF3) decreased noticeably. These results suggest that the solvation energy for ions in Cl-(CH2)m-Cl increases with m, regardless of hydrophilic or lipophilic nature of the ions. Based on these findings, the advantage of using Cl-(CH2)m-Cl with a large m as a non-aqueous solvent for ion-transfer voltammetry was discussed.
研究了烷基和全氟烷基羧酸根离子(CH3(CH2)n-2COO-,n = 8-12;CF3(CF2)n-2COO-,n = 3-9)在极化的 Cl-(CH2)m-Cl(m = 2、4、6 和 8 (O) | 水 (W) 界面上的离子转移反应,以评估 n 和 m 对离子的溶解能及其亚甲基和末端基团的影响。由于这些离子在 O | W 界面上的转移,它们表现出可逆或准可逆伏安波,从而确定了从 O 到 W 的形式电势和形式吉布斯转移能 Δ G tr,o → w 0 ' CH3(CH2)n-2COO- 和 CF3(CF2)n-2COO- 的 Δ G tr,o → w 0 ' 值随 n 线性增加、这样就可以估算出亚甲基和二氟亚甲基的 Δ G tr,o → w 0 ' 值:Δ G tr,o → w 0 ' (CH2) 和 Δ G tr,o → w 0 ' (CF2),以及它们的末端基团:Δ G tr,o → w 0 ' (COO- + CH3) 和 Δ G tr,o → w 0 ' (COO- + CF3)。随着 m 的变化,Δ G tr,o → w 0 ' (CH2)和Δ G tr,o → w 0 ' (CF2)几乎没有变化,而Δ G tr,o → w 0 ' (COO- + CH3)和Δ G tr,o → w 0 ' (COO- + CF3)则明显下降。这些结果表明,Cl-(CH2)m-Cl 中离子的溶解能随 m 的增加而增加,与离子的亲水性或亲脂性无关。基于这些发现,讨论了使用大 m 值的 Cl-(CH2)m-Cl 作为离子转移伏安法的非水溶剂的优势。
期刊介绍:
Analytical Sciences is an international journal published monthly by The Japan Society for Analytical Chemistry. The journal publishes papers on all aspects of the theory and practice of analytical sciences, including fundamental and applied, inorganic and organic, wet chemical and instrumental methods.
This publication is supported in part by the Grant-in-Aid for Publication of Scientific Research Result of the Japanese Ministry of Education, Culture, Sports, Science and Technology.