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Role of hydrogen bonds in ionic - liquid - mediated extraction of natural bioactive homologues / Kun Dong in Industrial & engineering chemistry research, Vol. 51 N° 14 (Avril 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5299–5308 Titre : Role of hydrogen bonds in ionic - liquid - mediated extraction of natural bioactive homologues Type de document : texte imprimé Auteurs : Kun Dong, Auteur ; Yifeng Cao, Auteur ; Qiwei Yang, Auteur Année de publication : 2012 Article en page(s) : pp. 5299–5308 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrogen  Ionic  liquid Résumé : The technologies of ionic-liquid-mediated extraction have shown the good prospects for replacing traditional methods for separating natural bioactive homologues. However, so far, the roles and interactions of the anions and cations in the extraction process are not clear, which seriously hinders the further exploration of this new extraction technology. In this work, we report a detailed computational study, combined with experiment, on the interactions and hydrogen bonds between 1-butyl-3-methylimidazlium hexafluorophosphate ([Bmim][PF6]) ionic liquid (IL) and natural bioactive homologues, namely, three soybean isoflavone aglycones as model compounds. The distribution coefficients, D, of the three aglycones were experimentally determined in the [Bmim][PF6]–water biphasic system, and the order was found to be genistein (182.6) > daidzein (51.4) > glycitein (41.9). In DFT calculations, the lowest-energy complexes were obtained, and it was found that H-bonds are explicit intermolecular interactions in these complexes and that the IL can recognize these similar homologues by forming different H-bonds with the phenolic hydroxyls of aglycones. Furthermore, we found that the anions play a more important role in recognition than the cations. Subsequently, results of molecular dynamics (MD) simulations exhibited a good match with the structures of the isolated complexes calculated by DFT and also discovered that H-bonds were the main interactions between the anions and the phenolic hydroxyls in the first solvation shell. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203044m [article] Role of hydrogen bonds in ionic - liquid - mediated extraction of natural bioactive homologues [texte imprimé] / Kun Dong, Auteur ; Yifeng Cao, Auteur ; Qiwei Yang, Auteur . - 2012 . - pp. 5299–5308. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5299–5308 Mots-clés : Hydrogen  Ionic  liquid Résumé : The technologies of ionic-liquid-mediated extraction have shown the good prospects for replacing traditional methods for separating natural bioactive homologues. However, so far, the roles and interactions of the anions and cations in the extraction process are not clear, which seriously hinders the further exploration of this new extraction technology. In this work, we report a detailed computational study, combined with experiment, on the interactions and hydrogen bonds between 1-butyl-3-methylimidazlium hexafluorophosphate ([Bmim][PF6]) ionic liquid (IL) and natural bioactive homologues, namely, three soybean isoflavone aglycones as model compounds. The distribution coefficients, D, of the three aglycones were experimentally determined in the [Bmim][PF6]–water biphasic system, and the order was found to be genistein (182.6) > daidzein (51.4) > glycitein (41.9). In DFT calculations, the lowest-energy complexes were obtained, and it was found that H-bonds are explicit intermolecular interactions in these complexes and that the IL can recognize these similar homologues by forming different H-bonds with the phenolic hydroxyls of aglycones. Furthermore, we found that the anions play a more important role in recognition than the cations. Subsequently, results of molecular dynamics (MD) simulations exhibited a good match with the structures of the isolated complexes calculated by DFT and also discovered that H-bonds were the main interactions between the anions and the phenolic hydroxyls in the first solvation shell. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203044m

Selective extraction of 1 - hexene against n - hexane in ionic liquids with or without silver salt / Rulong Li in Industrial & engineering chemistry research, Vol. 51 N° 25 (Juin 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8588-8597 Titre : Selective extraction of 1 - hexene against n - hexane in ionic liquids with or without silver salt Type de document : texte imprimé Auteurs : Rulong Li, Auteur ; Huabin Xing, Auteur ; Qiwei Yang, Auteur Année de publication : 2012 Article en page(s) : pp. 8588-8597 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic  liquid  Selective  extraction Résumé : This paper presents an extensive study on the feasibility of ionic liquids (ILs) for the extractive separation of a 1-hexene/n-hexane mixture. Seventeen ILs were tested at 313 K. The extraction selectivities of 1-hexene to n-hexane were in the range 1.5-3.0. The chemical structures of anion and cation in ILs greatly affected the extraction, and the functional groups, such as carbon―carbon double bond, nitrile, ester, and amide, in the ILs led to higher selectivities. The increase of alkyl chain length in cation led to the increase of extraction capacity of I-hexene. To increase the distribution of 1-hexene in IL phase, silver salt was added to the ILs. It was found that ILs containing silver salt had a high distribution of 1-hexene, as well as high selectivity of 1-hexene against n-hexane. The extraction efficiency increased with the concentration of silver salt in ILs. When the initial feed concentration of 1-hexene was smaller, the selectivity of 1-hexene to n-hexane was higher. A simple mathematical model has been developed to describe the total 1-hexene content in the reaction media under study, on the basis of the formation of complexes between silver and 1-hexene with different stoichiometry. This work proves that the ILs can act as effective extractants in 1-hexene/n-hexane separation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066785 [article] Selective extraction of 1 - hexene against n - hexane in ionic liquids with or without silver salt [texte imprimé] / Rulong Li, Auteur ; Huabin Xing, Auteur ; Qiwei Yang, Auteur . - 2012 . - pp. 8588-8597. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8588-8597 Mots-clés : Ionic  liquid  Selective  extraction Résumé : This paper presents an extensive study on the feasibility of ionic liquids (ILs) for the extractive separation of a 1-hexene/n-hexane mixture. Seventeen ILs were tested at 313 K. The extraction selectivities of 1-hexene to n-hexane were in the range 1.5-3.0. The chemical structures of anion and cation in ILs greatly affected the extraction, and the functional groups, such as carbon―carbon double bond, nitrile, ester, and amide, in the ILs led to higher selectivities. The increase of alkyl chain length in cation led to the increase of extraction capacity of I-hexene. To increase the distribution of 1-hexene in IL phase, silver salt was added to the ILs. It was found that ILs containing silver salt had a high distribution of 1-hexene, as well as high selectivity of 1-hexene against n-hexane. The extraction efficiency increased with the concentration of silver salt in ILs. When the initial feed concentration of 1-hexene was smaller, the selectivity of 1-hexene to n-hexane was higher. A simple mathematical model has been developed to describe the total 1-hexene content in the reaction media under study, on the basis of the formation of complexes between silver and 1-hexene with different stoichiometry. This work proves that the ILs can act as effective extractants in 1-hexene/n-hexane separation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26066785

Selective liquid – liquid extraction of natural phenolic compounds using amino acid ionic liquids / Xiaolei Ni in Industrial & engineering chemistry research, Vol. 51 N° 18 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 18 (Mai 2012) . - pp. 6480-6488 Titre : Selective liquid – liquid extraction of natural phenolic compounds using amino acid ionic liquids : A case of α - tocopherol and methyl linoleate separation Type de document : texte imprimé Auteurs : Xiaolei Ni, Auteur ; Huabin Xing, Auteur ; Qiwei Yang, Auteur Année de publication : 2012 Article en page(s) : pp. 6480-6488 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic  liquid  Liquid  liquid  extraction Résumé : Amino acid ironic liquids (AAlLs) with different amino acid anions were investigated in the selective separation of a typical natural phenoliç product, α-tocoperol, from its mixture with methyl linoleate by liquid―liquid extraction. A large separation selectivity, suitable distribution coefficient, and adequate extraction capacity were achieved with the AAIL/N,V-dimethylformamide (DMF) mixture as extractant. The selectivity of α-tocopherol to methyl linoleate reached up to 29 when using [emim]Ala and [emim]Lys as the extractant diluted by DMF with mole ratio of AAIL to DMF 15:85, at least 9 times larger than that using DMF or common ILs as the extractant. The presence of diluents, DMF, can not only reduce the viscosity of IL phase, but could also lead to much larger distribution coefficients. Back extraction of α-tocopherol using hexane and reuse of AAIL were both tested. Solvatochromic and infrared spectra measurements were used to investigate the mechanism of α-tocopherol extraction with ILs. A dose linear relationship can be drawn between the distribution coefficients of α-tocopherol and the hydrogen-bond basicity (β) of the extraction solvents, and also between the selectivites and the β values. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25867299 [article] Selective liquid – liquid extraction of natural phenolic compounds using amino acid ionic liquids : A case of α - tocopherol and methyl linoleate separation [texte imprimé] / Xiaolei Ni, Auteur ; Huabin Xing, Auteur ; Qiwei Yang, Auteur . - 2012 . - pp. 6480-6488. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 18 (Mai 2012) . - pp. 6480-6488 Mots-clés : Ionic  liquid  Liquid  liquid  extraction Résumé : Amino acid ironic liquids (AAlLs) with different amino acid anions were investigated in the selective separation of a typical natural phenoliç product, α-tocoperol, from its mixture with methyl linoleate by liquid―liquid extraction. A large separation selectivity, suitable distribution coefficient, and adequate extraction capacity were achieved with the AAIL/N,V-dimethylformamide (DMF) mixture as extractant. The selectivity of α-tocopherol to methyl linoleate reached up to 29 when using [emim]Ala and [emim]Lys as the extractant diluted by DMF with mole ratio of AAIL to DMF 15:85, at least 9 times larger than that using DMF or common ILs as the extractant. The presence of diluents, DMF, can not only reduce the viscosity of IL phase, but could also lead to much larger distribution coefficients. Back extraction of α-tocopherol using hexane and reuse of AAIL were both tested. Solvatochromic and infrared spectra measurements were used to investigate the mechanism of α-tocopherol extraction with ILs. A dose linear relationship can be drawn between the distribution coefficients of α-tocopherol and the hydrogen-bond basicity (β) of the extraction solvents, and also between the selectivites and the β values. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25867299

Selective separation of tocopherol homologues by liquid-liquid extraction using ionic liquids / Qiwei Yang in Industrial & engineering chemistry research, Vol. 48 N° 13 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6417–6422 Titre : Selective separation of tocopherol homologues by liquid-liquid extraction using ionic liquids Type de document : texte imprimé Auteurs : Qiwei Yang, Auteur ; Huabin Xing, Auteur ; Yifeng Cao, Auteur Année de publication : 2009 Article en page(s) : pp. 6417–6422 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Pocopherol  homologues  Liquid-liquid  extraction  Ionic  liquid Résumé : Selective separation of tocopherol homologues was performed by liquid−liquid extraction, using ionic liquids (ILs) as extractants in the presence of diluent. The distribution coefficients and selectivities of tocopherols in the biphasic system were determined. A selectivity of δ-tocopherol to α-tocopherol up to 21.3 was achieved when using [bmim]Cl as extractant diluted by methanol. Considering the structural differences of tocopherols, the separation mechanism based on the hydrogen-bonding interaction between IL’s anion and the −OH group on the tocopherols was proposed. The separation efficiency of IL was greatly affected by its anion, and followed the order [bmim]BF4 < [bmim]CF3SO3 < [bmim]Cl under the same conditions, which is consistent with the ascending order of IL’s hydrogen-bond basicity strengths. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801847e [article] Selective separation of tocopherol homologues by liquid-liquid extraction using ionic liquids [texte imprimé] / Qiwei Yang, Auteur ; Huabin Xing, Auteur ; Yifeng Cao, Auteur . - 2009 . - pp. 6417–6422. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6417–6422 Mots-clés : Pocopherol  homologues  Liquid-liquid  extraction  Ionic  liquid Résumé : Selective separation of tocopherol homologues was performed by liquid−liquid extraction, using ionic liquids (ILs) as extractants in the presence of diluent. The distribution coefficients and selectivities of tocopherols in the biphasic system were determined. A selectivity of δ-tocopherol to α-tocopherol up to 21.3 was achieved when using [bmim]Cl as extractant diluted by methanol. Considering the structural differences of tocopherols, the separation mechanism based on the hydrogen-bonding interaction between IL’s anion and the −OH group on the tocopherols was proposed. The separation efficiency of IL was greatly affected by its anion, and followed the order [bmim]BF4 < [bmim]CF3SO3 < [bmim]Cl under the same conditions, which is consistent with the ascending order of IL’s hydrogen-bond basicity strengths. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801847e