NMR pD-variation method to determine the proper stabilities of organic electrolyte complexes: case of histidine complexes with a cyclophane acid

IF 2.1 4区化学 Q3 CHEMISTRY, MULTIDISCIPLINARY

Supramolecular Chemistry Pub Date : 2021-10-03 DOI:10.1080/10610278.2022.2134017

R. Navarro, Yedith Soberanes, M. Inoue

{"title":"NMR pD-variation method to determine the proper stabilities of organic electrolyte complexes: case of histidine complexes with a cyclophane acid","authors":"R. Navarro, Yedith Soberanes, M. Inoue","doi":"10.1080/10610278.2022.2134017","DOIUrl":null,"url":null,"abstract":"ABSTRACT The complexation of organic electrolytes, like carboxylic acids and amines, is studied usually by spectrometric titration at a constant pH. Obtained stability constants are, however, conditional and dependent on the pH selected, differing from the proper constants. In nuclear magnetic resonance (NMR) titration in D2O, a stability constant determined at a given pD is not directly correlated to other properties observed at a pH in H2O because of difference between acid dissociations in the solvents. To overcome these problems, this report proposes pD-variable NMR spectrometry, which monitors NMR signals of a mixture of the reactants with the variation of pD. This method identifies complexes formed in different pD ranges, and determines the proper stability constants, to yield the species distribution, which can be replotted in pH scale. The usefulness and limitation are examined by simulation of titration curves. An experimental example is presented for complexation of histidine with a cyclophane acid. Excel® files for calculations are available in Supplementary material. Graphical Abstract","PeriodicalId":22084,"journal":{"name":"Supramolecular Chemistry","volume":"26 1","pages":"598 - 604"},"PeriodicalIF":2.1000,"publicationDate":"2021-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Supramolecular Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1080/10610278.2022.2134017","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 1

Abstract

ABSTRACT The complexation of organic electrolytes, like carboxylic acids and amines, is studied usually by spectrometric titration at a constant pH. Obtained stability constants are, however, conditional and dependent on the pH selected, differing from the proper constants. In nuclear magnetic resonance (NMR) titration in D2O, a stability constant determined at a given pD is not directly correlated to other properties observed at a pH in H2O because of difference between acid dissociations in the solvents. To overcome these problems, this report proposes pD-variable NMR spectrometry, which monitors NMR signals of a mixture of the reactants with the variation of pD. This method identifies complexes formed in different pD ranges, and determines the proper stability constants, to yield the species distribution, which can be replotted in pH scale. The usefulness and limitation are examined by simulation of titration curves. An experimental example is presented for complexation of histidine with a cyclophane acid. Excel® files for calculations are available in Supplementary material. Graphical Abstract

查看原文本刊更多论文

核磁共振pd -变化法测定有机电解质配合物的适当稳定性:组氨酸与环烷酸配合物的例子

有机电解质(如羧酸和胺)的络合通常是通过恒定pH下的光谱滴定来研究的。然而，所获得的稳定常数是有条件的，依赖于所选择的pH，与适当的常数不同。在D2O中的核磁共振(NMR)滴定中，在给定pD下测定的稳定常数与在H2O中pH值下观察到的其他性质不直接相关，因为溶剂中酸解离的差异。为了克服这些问题，本报告提出了pD可变核磁共振光谱法，该方法可以监测随pD变化的反应物混合物的核磁共振信号。该方法鉴定了在不同pD范围内形成的配合物，并确定了合适的稳定性常数，从而得到了物质分布，并可以在pH尺度上重新绘制。通过模拟滴定曲线，验证了该方法的实用性和局限性。给出了组氨酸与环烷酸络合的实验实例。用于计算的Excel®文件可在补充材料中找到。图形抽象

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Supramolecular Chemistry 化学-化学综合

CiteScore

3.60

自引率

3.00%

发文量

审稿时长

2.7 months

期刊介绍： Supramolecular Chemistry welcomes manuscripts from the fields and sub-disciplines related to supramolecular chemistry and non-covalent interactions. From host-guest chemistry, self-assembly and systems chemistry, through materials chemistry and biochemical systems, we interpret supramolecular chemistry in the broadest possible sense. Interdisciplinary manuscripts are particularly encouraged. Manuscript types include: high priority communications; full papers; reviews, and; Methods papers, techniques tutorials highlighting procedures and technologies that are important to the field. We aim to publish papers in a timely fashion and as soon as a paper has been accepted and typeset it will be published in electronic form on the Latest articles section of the website. The two most important review criteria are that the paper presents high-quality work that fits generally into the broad spectrum of activities in the supramolecular chemistry field. Under normal circumstances, Supramolecular Chemistry does not consider manuscripts that would be more suitable in a highly specialized journal. This includes, but is not limited to, those based mostly or exclusively on topics such as solid state/X-ray structures, computational chemistry, or electrochemistry. . The two most important review criteria are that the paper presents high-quality work that fits generally into the broad spectrum of activities in the supramolecular chemistry field.