Jun Fan

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Name: 范军; Jun Fan

Organization: South China Normal University , China

Department: School of Chemistry and Environment

Title: Professor(PhD)

TOPICS

Inorganic Chemistry

Organic Chemistry

Cyclodextrin

Chemicals
References

Stereoselective quantification of triticonazole in vegetables by supercritical fluid chromatography

Co-reporter:Qi Tan, Jun Fan, Ruiqi Gao, Rujian He, Tai Wang, Yaomou Zhang, Weiguang Zhang

Talanta 2017 Volume 164() pp:362-367

Publication Date(Web):1 March 2017

DOI:10.1016/j.talanta.2016.08.077

•A highly fast analysis and quantification method for triticonazole racemate by SFC.•Residue analysis of triticonazole enantiomers in some vegetables.•Effects of organic modifier on separation and quantification of triticonazole.•Analysis time through SFC was six-fold shorter than through HPLC.A highly fast analytical method though supercritical fluid chromatography (SFC) has been developed to quantify triticonazole enantiomers in cucumbers and tomatoes. Effects of organic modifier type and concentration on chiral separation and quantification of standard solution as well as matrix-matched standard solutions have been studied in detail. Among three organic modifiers, better separation of triticonazole racemate was achieved with 20% ethanol (v/v). The run time in SFC (ca 3 min) with CO2-ethanol (80:20, v/v) as the mobile phase was six-fold shorter than HPLC analysis (about 18 min). Then, QuEChERS (quick, easy, cheap, effective, rugged and safe) extraction procedure was used for triticonazole in vegetables. The residue analysis method was validated. Good linearity (R2≥0.9988) and recoveries (81.62–106.21%, RSD≤7.30%) for the two enantiomers were achieved. This developed method described herein is convenient and reliable for enantioselective detection of triticonazole in vegetables, which might provide additional information for reliable risk assessment of chiral pesticides.

Analysis of metalaxyl racemate using high performance liquid chromatography coupled with four kinds of detectors

Co-reporter:Tao Chen, Jun Fan, Ruiqi Gao, Tai Wang, Ying Yu, Weiguang Zhang

Journal of Chromatography A 2016 Volume 1467() pp:246-254

Publication Date(Web):7 October 2016

DOI:10.1016/j.chroma.2016.07.007

•Chiral separations of metalaxyl by HPLC coupled with four detectors.•Effect of chromatographic conditions on peak area ratio between two enantiomers.•Comparative evaluation of four detectors for quantification of enantiomers.Chiral stationary phase-high performance liquid chromatography coupled with various detectors has been one of most commonly used methods for analysis and separation of chiral compounds over the past decades. Various detectors exhibit different characteristics in qualitative and quantitative studies under different chromatographic conditions. Herein, a comparative evaluation of HPLC coupled with ultraviolet, optical rotation, refractive index, and evaporative light scattering detectors has been conducted for qualitative and quantitative analyses of metalaxyl racemate. Effects of separation conditions on the peak area ratio between two enantiomers, including sample concentration, column temperature, mobile phase composition, as well as flow rate, have been investigated in detail. In addition, the limits of detection, the limits of quantitation, quantitative range and precision for these two enantiomers by using four detectors have been also studied. As indicated, the chromatographic separation conditions have been slight effects on ultraviolet and refractive index detections and the peak area ratio between two enantiomers remains almost unchanged, but the evaporative light scattering detection has been significantly affected by the above-mentioned chromatographic conditions and the corresponding peak area ratios varied greatly. Moreover, the limits of detection, the limits of quantitation, and the quantitative ranges of two enantiomers with UV detection were remarkably lower by 1–2 magnitudes than the others.

Synthesis and enantioseparation behaviors of novel immobilized 3,5-dimethylphenylcarbamoylated polysaccharide chiral stationary phases

Co-reporter:Yi Tan;Chun Lin;Hongsheng Tu;Shengrun Zheng ;Weiguang Zhang

Journal of Separation Science 2014 Volume 37( Issue 5) pp:488-494

Publication Date(Web):

DOI:10.1002/jssc.201301146

Two new polysaccharide-derived chiral selectors, namely, 6-azido-6-deoxy-3,5-dimethylphenylcarbamoylated amylose and 6-azido-6-deoxy-3,5-dimethylphenyl carbamoylated cellulose, were synthesized under homogeneous conditions and immobilized onto aminized silica gel by the Staudinger reaction, resulting in two new immobilized polysaccharide chiral stationary phases (CSPs). Their enantioseparation performances were investigated under normal-phase mode by HPLC. Among 17 analytes, baseline separations of 12 pairs of enantiomers are achieved on the immobilized cellulose CSP, which demonstrates that this new cellulose material exhibits almost the same enantioseparation performance as the coated cellulose CSP. In addition, the amylose-derived CSP presents limited enantiorecognition ability but certain complementarity with the immobilized and coated cellulose-based materials. Neither metolachlor nor paclitaxel side chain acids are separated on two cellulose-derived CSPs, but effective separations are obtained on the immobilized amylose column.

Comparative HPLC enantioseparation on substituted phenylcarbamoylated cyclodextrin chiral stationary phases and mobile phase effects

Co-reporter:Chun Lin, Jun Fan, Wen-na Liu, Yi Tan, Wei-guang Zhang

Journal of Pharmaceutical and Biomedical Analysis 2014 Volume 98() pp:221-227

Publication Date(Web):September 2014

DOI:10.1016/j.jpba.2014.05.032

•Syntheses of two multi-urea-bound cyclodextrin CSPs via the Staudinger reactions.•Complimentary separation of π-acidic/basic phenylcarbamoylated cyclodextrin CSPs.•Effects of organic modifier and mobile phase pH on chiral recognition.•Elution order reversal of enantiomers induced by phenylcarbamate groups.Two new cyclodextrin-derived chiral stationary phases with multiple urea linkages were prepared through the Staudinger reactions between aminopropyl silica gel and cyclodextrin derivatives, namely, heptakis(6-azido-6-deoxy-2,3-di-O-3,5-dimethylphenylcarbamoylated)-β-cyclodextrin and heptakis(6-azido-6-deoxy-2,3-di-O-3,5-dichlorophenylcarbamoylated)-β-cyclodextrin, respectively. HPLC separation behaviors toward 46 chiral analytes have been investigated under multimodal elution. They exhibited good separation performances for these analytes and also showed some complimentary enantioselectivity to each other, due to different electron-donating (methyl)/withdrawing (chlorine) groups in the phenylcarbamate moieties. Among these analytes, aromatic alcohols and N-(2,4-dinitrophenyl)-derived carboxylic acids were better resolved on the π-basic chiral stationary phase than the π-acidic. The proton pump inhibitors, the 5-hydroxytryptamine receptor antagonists, and the analytes with carbonyl groups easily formed stereoselective interactions with the π-acidic chiral stationary phase, further leading to better enantioseparation. Elution order reversal for palonosetron and N-(2,4-dinitrophenyl) glutamine was observed in three chiral stationary phases, probably induced by the difference of phenylcarbamate groups. Moreover, mobile phase effects on retention behaviors of analytes have been studied in detail.

Reversal of elution order of N-(2,4-dinitrophenyl)-proline and N-(2,4-dinitrophenyl)-serine in HPLC by BSA chiral stationary phase

Co-reporter:Qiuyun Wang;Yajin Xiong;Baozhu Lu;Sheng Zhang;Shengrun Zheng;Weiguang Zhang

Journal of Separation Science 2013 Volume 36( Issue 8) pp:1343-1348

Publication Date(Web):

DOI:10.1002/jssc.201201165

N-(2,4-dinitrophenyl)-proline and N-(2,4-dinitrophenyl)-serine were enantiomerically resolved on the BSA chiral stationary phase by HPLC in reversed-phase mode. Effects of chromatographic conditions on enantioseparation and elution order have been investigated in detail. For these two samples, reversal of enantiomer elution order was observed by changing buffer pH, the content of acetonitrile, or alcohol modifiers in mobile phase, which is firstly reported in the BSA chiral stationary phase studies. More interestingly, combined effect between buffer pH and the content of acetonitrile was also observed. In addition, coelution range of enantiomers varied along with the content of acetonitrile in mobile phase.

Assembly of two new Mn(II) coordination polymers based on 5-aminoisophthalate: Structural diversity and properties

Co-reporter:Xia Yin, Tian-Tian Xiao, Jun Fan, Sheng-Run Zheng, Ning Wang, Song-Liang Cai, Jing-Bo Tan, Wei-Guang Zhang

Inorganic Chemistry Communications 2012 Volume 22() pp:93-97

Publication Date(Web):August 2012

DOI:10.1016/j.inoche.2012.05.031

Two new Mn(II) coordination polymers, namely, [Mn(Haip)2(H2O)2] (1), and [Mn2(aip)2(bpy)]·3H2O (2) were obtained under hydrothermal conditions (aip = 5-aminoisophthalate; bpy = 2, 2′-bipyridine). Compound 1 features a 1D loop-like chain structure, and complex 2 possesses an interesting (3, 5)-connected 2-nodal 3D architecture with the Schläfli symbol of (4.62)(4.67.82), which is constructed from helical chains. Coordination modes of H2aip molecules and coligands have significant effect on the structures of the resulting complexes. Moreover, variable-temperature magnetic susceptibility measurement of complex 2 exhibits antiferromagnetic interactions between nearest Mn(II) ions with J = − 0.88(5) cm− 1 and g = 2.04(3).Two complexes possess a 1D chain and a (3, 5)-connected 2-nodal 3D architecture, respectively. Variable-temperature magnetic susceptibility measurement of compound 2 shows antiferromagnetic interactions between nearest Mn(II) ions.Highlights► Two complexes with different topologies are obtained via hydrothermal reactions. ► Complex 2 was constructed by connection of dinuclear Mn(II) building blocks. ► Coligand and coordination modes of aip affected on structures of two complexes. ► Complex 2 exhibits antiferromagnetic interactions between nearest Mn(II) ions.

Luminescent lanthanide complexes with 4-acetamidobenzoate: Synthesis, supramolecular assembly via hydrogen bonds, crystal structures and photoluminescence

Co-reporter:Xia Yin, Jun Fan, Zhi Hong Wang, Sheng Run Zheng, Jing Bo Tan, Wei Guang Zhang

Journal of Solid State Chemistry 2011 Volume 184(Issue 7) pp:1850-1857

Publication Date(Web):July 2011

DOI:10.1016/j.jssc.2011.05.018

Four new luminescent complexes, namely, [Eu(aba)2(NO3)(C2H5OH)2] (1), [Eu(aba)3(H2O)2]·0.5 (4, 4′-bpy)·2H2O (2), [Eu2(aba)4(2, 2′-bpy)2(NO3)2]·4H2O (3) and [Tb2(aba)4(phen)2(NO3)2]·2C2H5OH (4) were obtained by treating Ln(NO3)3·6H2O and 4-acetamidobenzoic acid (Haba) with different coligands (4, 4′-bpy=4, 4′–bipyridine, 2, 2′-bpy=2, 2′-bipyridine, and phen=1, 10-phenanthroline). They exhibit 1D chains (1–2) and dimeric structures (3–4), respectively. This structural variation is mainly attributed to the change of coligands and various coordination modes of aba molecules. Moreover, the coordination units are further connected via hydrogen bonds to form 2D even 3D supramolecular networks. These complexes show characteristic emissions in the visible region at room temperature. In addition, thermal behaviors of four complexes have been investigated under air atmosphere. The relationship between the structures and physical properties has been discussed.Graphical abstractStructure variation of four complexes is attributed to the change of coligands and various coordination modes of aba molecules. Moreover, they show characteristic emissions in the visible region. Highlights► Auxiliary ligands have played the crucial roles on the structures of the resulting complexes. ► Isolated structure units are further assembled via H-bonds to form supramolecular networks. ► These solid-state complexes exhibit strong, characteristic emissions in the visible region.

Synthesis, crystal structures and photoluminescent properties of lanthanide supramolecular complexes with 4-oxo-1(4H)-quinolineacetate

Co-reporter:Jun Wang, Jun Fan, LiangYu Guo, Xia Yin, ZhiHong Wang, WeiGuang Zhang

Journal of Solid State Chemistry 2010 Volume 183(Issue 3) pp:575-583

Publication Date(Web):March 2010

DOI:10.1016/j.jssc.2009.12.027

Five new lanthanide supramolecular complexes, namely, [Sm(oqa)2(H2O)4]2 (ClO4)2·(bpy)2 (1), [Ln(oqa)3]·2H2O [Ln=Sm(2), Gd(3)] and [Ln(oqa)2(NO3)(H2O)] [Ln=Pr(4), Eu(5)] (oqa=4-oxo-1(4H)-quinolineacetate, bpy=4,4′-bipyridine), have been synthesized under hydrothermal conditions. These complexes exhibit three typical structure features. Complex 1 possesses a dimeric structure, which is further connected together through hydrogen bonds and π–π attractions, forming a 3D supramolecular framework. Compounds 2–3 are isomorphous and contain 1D ring-like chains, which are further interconnected by the oqa ligands into 2D sheet-like structures. 4 and 5 exhibit eight-connected 3D network of 424·64-bcu topology. The various coordination modes of carboxylate ligands and the selection of the counterions have clearly affected the topological structures. Furthermore, the solid-state luminescent properties of complexes 1, 2 and 5 were investigated at room temperature and they show intense, characteristic emissions in the visible region.The hydrothermal reactions of the oqa molecules with varied lanthanide ions resulted in the formation of five new complexes, which exhibit three typical structure features.

Three new coordination polymers based on 4-oxo-1(4H)quinolineacetate: Synthesis, structures and luminescent properties

Co-reporter:Jun Wang, Jun Fan, Liang-Yu Guo, Xia Yin, Zhi-Hong Wang, Wei-Guang Zhang

Inorganic Chemistry Communications 2010 Volume 13(Issue 2) pp:322-325

Publication Date(Web):February 2010

DOI:10.1016/j.inoche.2009.12.015

Synthesis, characterization, structures and magnetic property of chiral oxalate-bridged dicopper(II) complexes

Co-reporter:Ling Wu;Jun Wang;CaiFei Zhu;YiJi Lin;LeiQi Chen

Science China Chemistry 2010 Volume 53( Issue 6) pp:1255-1260

Publication Date(Web):2010 June

DOI:10.1007/s11426-010-3187-9

The oxalato-bridged dicopper(II) complexes [Cu2(μ-ox)(LRR)2(H2O)2(ClO4)2] (1), [Cu2(μ-ox)(LRR)2(CH3COCH3)2(ClO4)2](1a), [Cu2(μ-ox)(LSS)2(H2O)2(ClO4)2] (2) and [Cu2(μ-ox)(LRR)(LSS)2(CH3COCH3)2(ClO4)2] (3) [LRR = (8R,10R)-(−)-[4,5]-pineno-2,2′-bipyridine, LSS = (8S,10S)-(+)-[4,5]-pineno-2,2′-bipyridine; ox2− = oxalate] were first prepared. A possible mechanism for the formation of the chial dicopper(II) complexes was proposed. Based on elemental analysis, conductance measurement, UV-Vis spectra, CD spectra and X-ray single-crystal diffraction, the oxalato-bridged structures of 1 and 2 were deduced to adopt two Cu(II) ions and the bridged oxalate lying in the nearly same plane. The crystal structures of 1a and 3 reveal that the coordination geometry around each Cu(II) ion is an elongated and distorted octahedron and two axial solvent molecules and two perchlorate ions are anti to each other respectively in both binuclear molecules. The solution CD spectra of 1 and 2 in the visible d-d range show very weak Cotton effects with peaks at 588 and 779 nm, which are approximately of mirror image, suggesting the optical activities may be derived from the vicinal effects of the chiragenic centers at the pinene group of LRR and LSS, respectively. Complex 1 has been characterized by variable-temperature magnetic susceptibility and the data was least-square fitted to the Blenaey-Bowers equation. The exchange integral J was found to be −338.41(4) cm−1 indicating a strong antiferromagnetic interaction between two copper(II) ions.