Chiral recognition without π−π-interactions: Highly efficient chiral strong cation exchangers lacking an aromatic unit in the molecular structure

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F24%3A43929112" target="_blank" >RIV/60461373:22310/24:43929112 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/abs/pii/S002196732400102X" target="_blank" >https://www.sciencedirect.com/science/article/abs/pii/S002196732400102X</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.chroma.2024.464729" target="_blank" >10.1016/j.chroma.2024.464729</a>

Result language

angličtina

Original language name

Chiral recognition without π−π-interactions: Highly efficient chiral strong cation exchangers lacking an aromatic unit in the molecular structure

Original language description

Current state-of-the-art chiral stationary phases (CSPs) enable chiral resolution of almost any racemic mixture of choice. The exceptions represent ionizable and ionized substances that fail at any attempts to resolve on commercially available CSPs. These compounds, however, can be efficiently separated on chiral ion exchangers. Commercially available Cinchona alkaloids-based chiral weak ion-exchangers are typically used for chiral resolution of organic acids, while zwitterion ion-exchangers are efficient in the resolution of acids, bases, and zwitterions. The latter possess in their structure a cation exchange unit, which alone can serve as a cornerstone of chiral strong cation exchangers facilitating chiral separation of various basic racemic mixtures. Although chiral strong cation exchangers (cSCX) are efficient CSPs, their structural variations have not been thoroughly studied so far. It was assumed that the mechanism of chiral recognition of basic compounds by cSCX is based predominantly on π-π-interactions, hydrogen bonding and steric interactions (CSP I). To verify this assumption, we aimed in our study on the design and synthesis of cSCX first lacking lateral polar substituents on the aromatic unit in the selector&apos;s structure (CSP II), and second, to replace the aromatic unit by a cyclohexane ring (CSP III and IV), thereby to omit completely the π-π-interactions. We hypothesized that this structural change should lead to a partial or complete loss of enantiorecognition power of the selectors. Surprisingly, the non-aromatic cSCXs have shown chiral recognition capability comparable to that of previously described chiral cation exchange-type CSPs: from 16 analytes screened, 11 analytes were baseline resolved and 5 partially resolved on CSP I, while non-aromatic CSP III resolved 10 analytes baseline and 6 partially. We discuss the structural motifs of the known cSCX and the novel non-aromatic selectors in a relationship with their chromatographic performance using a set of basic analytes. Moreover, we present a theory of an effective chiral recognition mechanism by two novel non-aromatic cSCXs based on the chromatographic results and quantum mechanical calculations. © 2024 Elsevier B.V.

Czech name

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Czech description

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Type

J_SC - Article in a specialist periodical, which is included in the SCOPUS database

CEP classification

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OECD FORD branch

10401 - Organic chemistry

Project

<a href="/en/project/GC21-31139J" target="_blank" >GC21-31139J: Novel chiral ion-exchangers for chromatographic enantioseparations</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

JOURNAL OF CHROMATOGRAPHY A

ISSN

0021-9673

e-ISSN

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Volume of the periodical

1719

Issue of the periodical within the volume

březen 2024

Country of publishing house

ZA - SOUTH AFRICA

Number of pages

9

Pages from-to

464729

UT code for WoS article

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EID of the result in the Scopus database

2-s2.0-85186124540