Chiral separation of ten arylphenoxypropionate herbicides on four chiral columns by supercritical fluid chromatography

Yang, Xue; Ma, Binbin; Zheng, Xiaqiong; Lin, Chunmian

doi:10.1039/c4ay00364k

Cited by 11 publications

(8 citation statements)

References 33 publications

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“…For the chloro‐substituted CSPs (Chiralpak IC and Chiralpak ID), the presence of chlorine atoms on the phenyl ring may be the reason for their higher enantioselectivity abilities. The chlorine atom was reported to have a double role : (a) the stereoelectronic properties of the chlorine (electron‐withdrawing inductive effect) can influence close sites. In detail, the chloro‐substituted phenyl ring was π‐acidic, and could promote π‐π interaction with π‐basic phenyl ring of the enantiomer, further leading to a better chiral recognition.…”

Section: Resultsmentioning

confidence: 99%

“…Since the methoxyl (as the stronger electron‐donating group) increased the electron density of R 2 phenyl, racemate 3 was inclined to form enhanced π‐π interaction with the phenyl moiety of the CSP, further leading to a better chiral separation. Moreover, the methoxyl substituted phenyl (racemate 3) preferred to form halogen bonding with the chlorine atom (Lewis acid) of CSP, which also exerted a beneficial effect on enantioseparation . In contrast to racemates 1–4, racemates 5–12 had a benzyl substituent at R 1 instead of methyl.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Enantioselective separation of twelve pairs of enantiomers on polysaccharide‐based chiral stationary phases and thermodynamic analysis of separation mechanism

et al. 2018

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The enantioseparation of twelve pairs of structurally related 1-aryl-1-indanone derivatives was studied in the normal-phase mode using three different polysaccharide-type chiral stationary phases, namely Chiralpak IB, Chiralpak IC, and Chiralpak ID. n-Hexane/2-propanol and n-hexane/ethanol were employed as mobile phases. Among all the investigated chiral columns, Chiralpak IC exhibited the most universal and the best enantioseparation ability toward all the racemates, particularly with the mobile phase composed of n-hexane/2-propanol (90/10, v/v). Then the effects of column temperature on retention and enantioselectivity were examined in the range of 25-40°C. Satisfactory enantioseparation was obtained at ambient temperature. The natural logarithm of retention and separation factors (ln k and ln α) versus the reciprocal of absolute temperature (1/T) (Van't Hoff plots) were found to be linear for all racemates, indicating that the retention and separation mechanisms were independent of temperature in the range investigated. Then, the thermodynamic parameters (ΔΔH°, ΔΔS°, and ΔΔG°) were calculated from Van't Hoff plots. These values indicated that the solute transfer from the mobile to stationary phase was enthalpically favorable, and the process of enantioseparation was mainly enthalpy controlled. At last, the impact of small changes in molecular structures of the tested 1-indanone derivatives on enantioseparation was also discussed.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Enantioselective separation of twelve pairs of enantiomers on polysaccharide‐based chiral stationary phases and thermodynamic analysis of separation mechanism

et al. 2018

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“…Recently, Lin and colleagues studied the enantiomeric separations of 10 chiral arylphenoxypropionate herbicides (Table 11) on Sino-Chiral OJ, Chiralcel OD-H, Chiralpak IB and Chiralpak AD-H (250 × 4.6 mm, 5 μm) by SFC. 58 Supercritical CO 2 , modified with MeOH, EtOH, or IPA was used as MP (2 ml/min). Among the selected herbicides, clodinafoppropargyl and haloxyfop-methyl were not enantioseparated.…”

Section: Halogens In Hplc Enantioseparationsmentioning

confidence: 99%

Liquid Chromatography Enantioseparations of Halogenated Compounds on Polysaccharide‐Based Chiral Stationary Phases: Role of Halogen Substituents in Molecular Recognition

2015

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Halogenated chiral molecules have become important in several fields of science, industry, and society as drugs, natural compounds, agrochemicals, environmental pollutants, synthetic products, and chiral supports. Meanwhile, the perception of the halogen moiety in organic compounds and its role in recognition processes changed. Indeed, the recognition of the halogen bond as an intermolecular interaction occurring when the halogen acts as a Lewis acid had a strong impact, particularly in crystal engineering and medicinal chemistry. Due to this renewed interest in the potentialities of chiral organohalogens, here we focus on selected recent applications dealing with enantioseparations of halogenated compounds on polysaccharide-based chiral stationary phases (CSPs), widely used in liquid chromatography (LC). In particular, recently the first case of halogen bonding-driven high-performance LC (HPLC) enantioseparation was reported on a cellulose-based CSP. Along with enantioseparations performed under conventional HPLC, representative applications using supercritical fluid chromatography (SFC) are reported.

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“…In fact, the S ‐isomers fail to eliminate agricultural crop pests while exhibiting toxic side effects . For example, the enantiomeric activities of haloxyfop‐ p ‐methyl against annual grass weeds are mainly performed by the R ‐form, which enantiomer has a herbicidal activity 1000‐times higher than the S ‐form .…”

Section: Introductionmentioning

confidence: 99%

Chiral separation of aryloxyphenoxy‐propionate herbicides in a permethyl‐β‐cyclodextrin based column. Influence of temperature and mobile phase composition on enantioselectivity

Lubomirsky¹,

Padró²,

Loreto³

et al. 2017

Electrophoresis

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We used a permethyl-β-cyclodextrin chiral stationary phase under reversed-phase conditions for the chiral separation of four aryloxyphenoxy-propionate herbicides (fenoxaprop-p-ethyl, quizalofop-p-ethyl and tefuryl, and haloxyfop-p-methyl) with mixtures of methanol, ethanol, 2-propanol, n-propanol, tert-butanol, or acetonitrile and water as mobile phases and investigated the influence of mobile phase composition and column temperature (from 0 to 50°C) on the separation. The retention factors (k) and selectivity factors (α) of all the herbicides investigated decreased with increasing temperature. The lnα versus 1/T and lnk versus 1/T plots for the enantiomers of the chiral pesticides were linear within the range of 0-50°C with all alcohol/water mixtures constituting the mobile phase, but the lnk versus 1/T plots were nonlinear for all the enantiomers chromatographed in acetonitrile/water mixtures. The thermodynamic parameters based on linear van't Hoff plots were calculated. The influence of temperature and mobile phase composition on the enantioseparation of the solutes has rarely been considered simultaneously. The temperature and the solvents used in the mobile phase, however, were found to have a profound effect on the enantioseparation of these herbicides.

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Chiral separation of ten arylphenoxypropionate herbicides on four chiral columns by supercritical fluid chromatography

Abstract: Many chemical products used in the agrochemical industries contain chiral centers and consist of one or two pairs of enantiomers, which can have important consequences regarding bioactivity.

Cited by 11 publications

References 33 publications

Enantioselective separation of twelve pairs of enantiomers on polysaccharide‐based chiral stationary phases and thermodynamic analysis of separation mechanism

Enantioselective separation of twelve pairs of enantiomers on polysaccharide‐based chiral stationary phases and thermodynamic analysis of separation mechanism

Liquid Chromatography Enantioseparations of Halogenated Compounds on Polysaccharide‐Based Chiral Stationary Phases: Role of Halogen Substituents in Molecular Recognition

Chiral separation of aryloxyphenoxy‐propionate herbicides in a permethyl‐β‐cyclodextrin based column. Influence of temperature and mobile phase composition on enantioselectivity

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