The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform
Marius Ueffing - One of the best experts on this subject based on the ideXlab platform.
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improved mass spectrometric identificatIon of gel separated hydrophobic membrane proteins after sodium dodecyl sulfate removal by Ion Pair extractIon
Proteomics, 2004Co-Authors: Hans Zischka, Christian Johannes Gloeckner, Christian Klein, Stefanie Willmann, Magdalena Swiatekde Lange, Marius UeffingAbstract:SeparatIon and identificatIon of hydrophobic membrane proteins is a major challenge in proteomics. IdentificatIon of such sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)-separated proteins by peptide mass fingerprinting (PMF) via matrix-assisted laser desorptIon/IonizatIon-time of flight (MALDI-TOF) is frequently hampered by the insufficient amount of peptides being generated and their low signal intensity. Using the seven helical transmembrane-spanning proton pump bacteriorhodopsin as model protein, we demonstrate here that SDS removal from hydrophobic proteins by Ion-Pair extractIon prior to in-gel tryptic proteolysis leads to a tenfold higher sensitivity in mass spectrometric identificatIon via PMF, with respect to initial protein load on SDS-PAGE. Furthermore, parallel sequencing of the generated peptides by electrospray IonizatIon-mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS) was possible without further sample cleanup. We also show identificatIon of other membrane proteins by this protocol, as proof of general applicability.
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Improved mass spectrometric identificatIon of gel‐separated hydrophobic membrane proteins after sodium dodecyl sulfate removal by Ion‐Pair extractIon
Proteomics, 2004Co-Authors: Hans Zischka, Christian Johannes Gloeckner, Christian Klein, Stefanie Willmann, Magdalena Swiatekde Lange, Marius UeffingAbstract:SeparatIon and identificatIon of hydrophobic membrane proteins is a major challenge in proteomics. IdentificatIon of such sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)-separated proteins by peptide mass fingerprinting (PMF) via matrix-assisted laser desorptIon/IonizatIon-time of flight (MALDI-TOF) is frequently hampered by the insufficient amount of peptides being generated and their low signal intensity. Using the seven helical transmembrane-spanning proton pump bacteriorhodopsin as model protein, we demonstrate here that SDS removal from hydrophobic proteins by Ion-Pair extractIon prior to in-gel tryptic proteolysis leads to a tenfold higher sensitivity in mass spectrometric identificatIon via PMF, with respect to initial protein load on SDS-PAGE. Furthermore, parallel sequencing of the generated peptides by electrospray IonizatIon-mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS) was possible without further sample cleanup. We also show identificatIon of other membrane proteins by this protocol, as proof of general applicability.
Naoki Hirayama - One of the best experts on this subject based on the ideXlab platform.
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Synergistic Ion-Pair ExtractIon of Strontium Ion with Tri-n-octylphosphine Oxide and Dicyclohexano-18-crown-6
Analytical Sciences, 2016Co-Authors: Mami Onizaki, Kotaro Morita, Naoki HirayamaAbstract:: The co-use of two neutral ligands, tri-n-octylphosphine oxide (TOPO) and dicyclohexano-18-crown-6 (DC18C6), for Ion-Pair extractIon of divalent strontium (Sr2+) with bis(trifluoromethanesulfonyl)imide anIon (Tf2N-) showed unique synergistic effect. The extracted species in use of a single ligand is Sr(TOPO)32+·2Tf2N- or Sr(DC18C6)2+·2Tf2N-, whereas the co-use resulted in extractIon enhancement based on additIonal formatIon of Sr(DC18C6)(TOPO)2+·2Tf2N- and Sr(DC18C6)(TOPO)22+·2Tf2N-.
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Peculiar ExtractIon Behavior of Nickel (II) Originated in Steric Effect of Schiff Base Ligands in Ion-Pair ExtractIon Systems
Journal of ion exchange, 2007Co-Authors: Syunichi Oshima, Koji Kubono, Hisao Kokusen, Yu Komatsu, Naoki HirayamaAbstract:The Steric effect of two di-Schiff base ligands having phenylene skeleton as extractant on Ion-Pair extractIon of divalent metal catIons into nitorbenzene with picrate anIon was investigated. In these extractIon systems, all of the extractIon except for nickel was equilibrated within 1 h, and ratio of metal: ligand: picrate in the extracted species was 1: 2: 2 or 1: 3: 2. In the extractIon of nickel, 2 or 10 hours needed to be equilibrated and the Steric effect of ligands resulted in the change of the extracted species. Namely, a difference between the favorable extracted species for kinetics and equilibrium appeared by the steric effect. Consequently, nickel was extracted quantitatively and the highly selectivity for nickel was obtained.
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Ion Pair extractIon behavior of divalent metal catIons using neutral di schiff base ligands derived from 1 2 cyclohexanediamine and o phenylenediamine
Talanta, 2003Co-Authors: Syunichi Oshima, Naoki Hirayama, Koji Kubono, Hisao Kokusen, Takaharu HonjoAbstract:Abstract Di-Schiff base ligand, N , N '-bis(2-pyridylmethylidene)- trans -1,2-diiminocyclohexane ( trans -BPIC), having sufficient hydrophobicity acts as neutral bidentate ligand in Ion-Pair extractIon of divalent metal catIons into nitrobenzene with picrate anIon. In present study, the effect of steric restrictIon by chemical structure around imine-N donor atoms in trans -BPIC analogs on their complexatIon with divalent metal catIons in Ion-Pair extractIon was investigated by using N , N '-bis(2-pyridylmethylidene)- cis -1,2-diiminocyclohexane ( cis -BPIC) and N , N '-bis(2-pyridylmethylidene)- o -diiminobenezene (BPIB). The former was used to observe the effect by geometrical restrictIon and the latter was by conjugate restrictIon. In BPIB–NaPic system, the higher extractability was obtained than those in cis - and trans -BPIC systems, and this result seems to be led by the increase of steric distortIon originated from conformatIonal restrictIon. Namely, it is considered that the extractability can be controlled by steric restrictIon on the complexatIon.
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Ion-Pair extractIon behavior of divalent transitIon metal catIons as charged complexes with N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane and its analogues
Analytica Chimica Acta, 2001Co-Authors: Syunichi Oshima, Naoki Hirayama, Koji Kubono, Hisao Kokusen, Takaharu HonjoAbstract:The use of neutral di-Schiff base ligands, N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) and its analogues, N,N′-bis[1-(2-pyridyl)ethylidene]-1,2-diiminoethane (BPEE) and N,N′-bis(2-pyridylmethylidene)-trans-1,2-diiminocyclohexane (BPIC), as complexatIon reagents for Ion-Pair extractIon of divalent transitIon metal catIons into nitrobenzene with picrate anIon was investigated. The results of numerical analysis concerning the extractIon behavior indicated that they act as imine-N bidentate ligands in the extractIon system. Furthermore, the introductIon of the alkyl substituents onto imine-C on BPIE led to the change in the extractIon selectivity by steric distortIon of the catIonic complexes, whereas that onto ethylene-C only caused the enhancement of the extractability.
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Ion Pair extractIon behavior of divalent transitIon metal catIons as charged complexes with n n bis 2 pyridylmethylidene 1 2 diiminoethane and its analogues
Analytica Chimica Acta, 2001Co-Authors: Syunichi Oshima, Naoki Hirayama, Koji Kubono, Hisao Kokusen, Takaharu HonjoAbstract:The use of neutral di-Schiff base ligands, N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) and its analogues, N,N′-bis[1-(2-pyridyl)ethylidene]-1,2-diiminoethane (BPEE) and N,N′-bis(2-pyridylmethylidene)-trans-1,2-diiminocyclohexane (BPIC), as complexatIon reagents for Ion-Pair extractIon of divalent transitIon metal catIons into nitrobenzene with picrate anIon was investigated. The results of numerical analysis concerning the extractIon behavior indicated that they act as imine-N bidentate ligands in the extractIon system. Furthermore, the introductIon of the alkyl substituents onto imine-C on BPIE led to the change in the extractIon selectivity by steric distortIon of the catIonic complexes, whereas that onto ethylene-C only caused the enhancement of the extractability.
Mehmet Akyüz - One of the best experts on this subject based on the ideXlab platform.
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determinatIon of biogenic amines in licorice glycyrrhiza glabra by Ion Pair extractIon and liquid chromatography tandem mass spectrometry
Journal of the Science of Food and Agriculture, 2017Co-Authors: Mehmet Akyüz, Hasan ÇabukAbstract:BACKGROUND Ion-Pair extractIon combined with liquid chromatography–tandem mass spectrometry method has been proposed for the determinatIon of biogenic amines in licorice samples. RESULTS Limit of detectIon and limit of quantitatIon for the biogenic amines were 1.4–2.7 and 4.7–9.1 ng mL−1, respectively. Relative standard deviatIons based on five replicate extractIon of 100 ng mL−1 of each biogenic amine were <4.7% for intra-day and 7.4% for inter-day precisIon. The method described in this study has been shown to be in accordance with satisfactory accuracy and good reproducibility for the quantitative determinatIon of biogenic amines in licorice samples. Nine biogenic amines (putrescine, cadaverine, histamine, spermine, spermidine, tyramine, tryptamine, agmatine and phenylethylamine) were detected in licorice samples and total biogenic amine concentratIons were determined at 369 ng mL−1 in fresh and 3532 ng mL−1 in non-fresh licorice samples. Putrescine was found at the highest concentratIons to be up to 704 ng mL−1 in all the analyzed samples, followed by tyramine (675 ng mL−1) and tryptamine (282 ng mL−1). Putrescine, tyramine and spermine concentratIons were dramatically increased, whereas agmatine concentratIon was significantly decreased, in non-fresh licorice samples compared to fresh ones. CONCLUSIon The consumptIon of freshly prepared licorice is recommended because of the relatively low concentratIon of total biogenic amines. © 2016 Society of Chemical Industry
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DeterminatIon of biogenic amines in licorice (Glycyrrhiza glabra) by Ion-Pair extractIon and liquid chromatography-tandem mass spectrometry.
Journal of the Science of Food and Agriculture, 2016Co-Authors: Mehmet Akyüz, Hasan ÇabukAbstract:BACKGROUND Ion-Pair extractIon combined with liquid chromatography–tandem mass spectrometry method has been proposed for the determinatIon of biogenic amines in licorice samples. RESULTS Limit of detectIon and limit of quantitatIon for the biogenic amines were 1.4–2.7 and 4.7–9.1 ng mL−1, respectively. Relative standard deviatIons based on five replicate extractIon of 100 ng mL−1 of each biogenic amine were
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determinatIon of aromatic amines in hair dye and henna samples by Ion Pair extractIon and gas chromatography mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2008Co-Authors: Mehmet AkyüzAbstract:Abstract A gas chromatography–mass spectrometry (GC–MS) method has been proposed for the determinatIon of carcinogenic and toxic aromatic amines in hair dye, henna and dyed hair samples. The method includes Ion-Pair extractIon of aromatic amines from aqueous samples with bis-2-ethylhexylphosphate (BEHPA) released after solving the samples in acidic solutIon followed by sonicatIon, derivatisatIon of compounds with isobutyl chloroformate (IBCF) and their GC–MS analysis in both electron impact (EI) and positive and negative Ion chemical IonisatIon (PNICI) mode as their isobutyloxycarbonyl ( iso BOC) derivatives. The obtained recoveries of aromatic amines ranged from 92.2 to 98.4% and the precisIon of this method, as indicated by the relative standard deviatIons (RSDs) was within the range of 0.7–4.2%. The detectIon limits obtained from calculatIons by using GC–MS results based on signal-to-noise ratio (S/N)= 3 were within the range from 0.02 to 0.20 ng/g. In the present study, the commercially available 54 permanent hair dye, 35 modified or natural henna and 15 dyed hair samples were analysed for the aromatic amines by the proposed method and the method was shown to be suitable to determine the aromatic amine ingredients and metabolites of these commercial products.
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DeterminatIon of aromatic amines in hair dye and henna samples by Ion-Pair extractIon and gas chromatography–mass spectrometry
Journal of Pharmaceutical and Biomedical Analysis, 2007Co-Authors: Mehmet AkyüzAbstract:Abstract A gas chromatography–mass spectrometry (GC–MS) method has been proposed for the determinatIon of carcinogenic and toxic aromatic amines in hair dye, henna and dyed hair samples. The method includes Ion-Pair extractIon of aromatic amines from aqueous samples with bis-2-ethylhexylphosphate (BEHPA) released after solving the samples in acidic solutIon followed by sonicatIon, derivatisatIon of compounds with isobutyl chloroformate (IBCF) and their GC–MS analysis in both electron impact (EI) and positive and negative Ion chemical IonisatIon (PNICI) mode as their isobutyloxycarbonyl ( iso BOC) derivatives. The obtained recoveries of aromatic amines ranged from 92.2 to 98.4% and the precisIon of this method, as indicated by the relative standard deviatIons (RSDs) was within the range of 0.7–4.2%. The detectIon limits obtained from calculatIons by using GC–MS results based on signal-to-noise ratio (S/N)= 3 were within the range from 0.02 to 0.20 ng/g. In the present study, the commercially available 54 permanent hair dye, 35 modified or natural henna and 15 dyed hair samples were analysed for the aromatic amines by the proposed method and the method was shown to be suitable to determine the aromatic amine ingredients and metabolites of these commercial products.
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simultaneous determinatIon of aliphatic and aromatic amines in water and sediment samples by Ion Pair extractIon and gas chromatography mass spectrometry
Journal of Chromatography A, 2006Co-Authors: Mehmet AkyüzAbstract:Abstract A gas chromatography–mass spectrometry (GC–MS) method has been proposed for the determinatIon of aliphatic and aromatic amines in a variety of environmental samples including wastewater, river water, sea water and sediment samples. The method includes Ion-Pair extractIon with bis-2-ethylhexylphosphate (BEHPA), derivatisatIon of compounds with isobutyl chloroformate (IBCF) and their GC–MS analysis. Aliphatic and aromatic amines were isolated from aqueous samples using BEHPA as Ion-Pair reagent and derivatised with IBCF for their chromatographic analysis. Solid–liquid extractIon of aliphatic and aromatic amines in sediment samples were performed in Soxhlet apparatus with acidic MeOH and Ion-Pair extractIon with BEHPA were carried out for the isolatIon of amines followed by derivatisatIon with IBCF. Aliphatic and aromatic amines were then analysed with GC–MS in both electron impact (EI) and positive and negative Ion chemical IonisatIon (PNICI) mode as their isobutyloxycarbonyl (isoBOC) derivatives. The obtained recoveries ranged from 81.0 to 98.0% and the precisIon of this method, as indicated by the relative standard deviatIons (RSDs) was within the range of 0.5 and 4.3%. The detectIon limits obtained from calculatIons by using GC–MS results based on S/N = 3 were within the range from 0.07 to 0.50 ng/l.
Takaharu Honjo - One of the best experts on this subject based on the ideXlab platform.
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Ion Pair extractIon behavior of divalent metal catIons using neutral di schiff base ligands derived from 1 2 cyclohexanediamine and o phenylenediamine
Talanta, 2003Co-Authors: Syunichi Oshima, Naoki Hirayama, Koji Kubono, Hisao Kokusen, Takaharu HonjoAbstract:Abstract Di-Schiff base ligand, N , N '-bis(2-pyridylmethylidene)- trans -1,2-diiminocyclohexane ( trans -BPIC), having sufficient hydrophobicity acts as neutral bidentate ligand in Ion-Pair extractIon of divalent metal catIons into nitrobenzene with picrate anIon. In present study, the effect of steric restrictIon by chemical structure around imine-N donor atoms in trans -BPIC analogs on their complexatIon with divalent metal catIons in Ion-Pair extractIon was investigated by using N , N '-bis(2-pyridylmethylidene)- cis -1,2-diiminocyclohexane ( cis -BPIC) and N , N '-bis(2-pyridylmethylidene)- o -diiminobenezene (BPIB). The former was used to observe the effect by geometrical restrictIon and the latter was by conjugate restrictIon. In BPIB–NaPic system, the higher extractability was obtained than those in cis - and trans -BPIC systems, and this result seems to be led by the increase of steric distortIon originated from conformatIonal restrictIon. Namely, it is considered that the extractability can be controlled by steric restrictIon on the complexatIon.
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Ion-Pair extractIon behavior of divalent transitIon metal catIons as charged complexes with N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane and its analogues
Analytica Chimica Acta, 2001Co-Authors: Syunichi Oshima, Naoki Hirayama, Koji Kubono, Hisao Kokusen, Takaharu HonjoAbstract:The use of neutral di-Schiff base ligands, N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) and its analogues, N,N′-bis[1-(2-pyridyl)ethylidene]-1,2-diiminoethane (BPEE) and N,N′-bis(2-pyridylmethylidene)-trans-1,2-diiminocyclohexane (BPIC), as complexatIon reagents for Ion-Pair extractIon of divalent transitIon metal catIons into nitrobenzene with picrate anIon was investigated. The results of numerical analysis concerning the extractIon behavior indicated that they act as imine-N bidentate ligands in the extractIon system. Furthermore, the introductIon of the alkyl substituents onto imine-C on BPIE led to the change in the extractIon selectivity by steric distortIon of the catIonic complexes, whereas that onto ethylene-C only caused the enhancement of the extractability.
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Ion Pair extractIon behavior of divalent transitIon metal catIons as charged complexes with n n bis 2 pyridylmethylidene 1 2 diiminoethane and its analogues
Analytica Chimica Acta, 2001Co-Authors: Syunichi Oshima, Naoki Hirayama, Koji Kubono, Hisao Kokusen, Takaharu HonjoAbstract:The use of neutral di-Schiff base ligands, N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) and its analogues, N,N′-bis[1-(2-pyridyl)ethylidene]-1,2-diiminoethane (BPEE) and N,N′-bis(2-pyridylmethylidene)-trans-1,2-diiminocyclohexane (BPIC), as complexatIon reagents for Ion-Pair extractIon of divalent transitIon metal catIons into nitrobenzene with picrate anIon was investigated. The results of numerical analysis concerning the extractIon behavior indicated that they act as imine-N bidentate ligands in the extractIon system. Furthermore, the introductIon of the alkyl substituents onto imine-C on BPIE led to the change in the extractIon selectivity by steric distortIon of the catIonic complexes, whereas that onto ethylene-C only caused the enhancement of the extractability.
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Ion-Pair extractIon behavior of transitIon metal(II) catIons as charged complexes with ethylenediamine derivatives having heterocyclic pendant arms
Analytica Chimica Acta, 1997Co-Authors: Naoki Hirayama, Koji Kubono, Hisao Kokusen, Shinji Iimuro, Takaharu HonjoAbstract:Abstract The use of N , N , N ′, N ′-tetrakis(1′-pyrazolylmethyl)-1,2-diaminoethane (tpzen), N , N , N ′, N ′-tetrakis(3′,5′-dimethylpyrazol-1′-ylmethyl)-1, 2-diaminoethane (Me 8 tpzen) and N , N , N ′, N ′-tetrakis(2′-pyridylmethyl)-1,2-diaminoethane (tpen) as complexatIon reagents for Ion-Pair extractIon of metal(II) catIons into nitrobenzene was investigated. The order of extractability of the metals was tpen > Me 8 tpzen > tpen. Although these molecules have four nitrogen-containing heterocyclic pendant arms and act as sexadentate ligands normally in aqueous solutIon, the result of numerical analysis concerning the extractIon behavior indicated that they act as bidentate ligands in the extractIon system. The pendant arms were not concerned in chelate formatIon and the arms acted to raise the hydrophobicity and the extractability of the complexes.
Syunichi Oshima - One of the best experts on this subject based on the ideXlab platform.
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Peculiar ExtractIon Behavior of Nickel (II) Originated in Steric Effect of Schiff Base Ligands in Ion-Pair ExtractIon Systems
Journal of ion exchange, 2007Co-Authors: Syunichi Oshima, Koji Kubono, Hisao Kokusen, Yu Komatsu, Naoki HirayamaAbstract:The Steric effect of two di-Schiff base ligands having phenylene skeleton as extractant on Ion-Pair extractIon of divalent metal catIons into nitorbenzene with picrate anIon was investigated. In these extractIon systems, all of the extractIon except for nickel was equilibrated within 1 h, and ratio of metal: ligand: picrate in the extracted species was 1: 2: 2 or 1: 3: 2. In the extractIon of nickel, 2 or 10 hours needed to be equilibrated and the Steric effect of ligands resulted in the change of the extracted species. Namely, a difference between the favorable extracted species for kinetics and equilibrium appeared by the steric effect. Consequently, nickel was extracted quantitatively and the highly selectivity for nickel was obtained.
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Ion Pair extractIon behavior of divalent metal catIons using neutral di schiff base ligands derived from 1 2 cyclohexanediamine and o phenylenediamine
Talanta, 2003Co-Authors: Syunichi Oshima, Naoki Hirayama, Koji Kubono, Hisao Kokusen, Takaharu HonjoAbstract:Abstract Di-Schiff base ligand, N , N '-bis(2-pyridylmethylidene)- trans -1,2-diiminocyclohexane ( trans -BPIC), having sufficient hydrophobicity acts as neutral bidentate ligand in Ion-Pair extractIon of divalent metal catIons into nitrobenzene with picrate anIon. In present study, the effect of steric restrictIon by chemical structure around imine-N donor atoms in trans -BPIC analogs on their complexatIon with divalent metal catIons in Ion-Pair extractIon was investigated by using N , N '-bis(2-pyridylmethylidene)- cis -1,2-diiminocyclohexane ( cis -BPIC) and N , N '-bis(2-pyridylmethylidene)- o -diiminobenezene (BPIB). The former was used to observe the effect by geometrical restrictIon and the latter was by conjugate restrictIon. In BPIB–NaPic system, the higher extractability was obtained than those in cis - and trans -BPIC systems, and this result seems to be led by the increase of steric distortIon originated from conformatIonal restrictIon. Namely, it is considered that the extractability can be controlled by steric restrictIon on the complexatIon.
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Ion-Pair extractIon behavior of divalent transitIon metal catIons as charged complexes with N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane and its analogues
Analytica Chimica Acta, 2001Co-Authors: Syunichi Oshima, Naoki Hirayama, Koji Kubono, Hisao Kokusen, Takaharu HonjoAbstract:The use of neutral di-Schiff base ligands, N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) and its analogues, N,N′-bis[1-(2-pyridyl)ethylidene]-1,2-diiminoethane (BPEE) and N,N′-bis(2-pyridylmethylidene)-trans-1,2-diiminocyclohexane (BPIC), as complexatIon reagents for Ion-Pair extractIon of divalent transitIon metal catIons into nitrobenzene with picrate anIon was investigated. The results of numerical analysis concerning the extractIon behavior indicated that they act as imine-N bidentate ligands in the extractIon system. Furthermore, the introductIon of the alkyl substituents onto imine-C on BPIE led to the change in the extractIon selectivity by steric distortIon of the catIonic complexes, whereas that onto ethylene-C only caused the enhancement of the extractability.
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Ion Pair extractIon behavior of divalent transitIon metal catIons as charged complexes with n n bis 2 pyridylmethylidene 1 2 diiminoethane and its analogues
Analytica Chimica Acta, 2001Co-Authors: Syunichi Oshima, Naoki Hirayama, Koji Kubono, Hisao Kokusen, Takaharu HonjoAbstract:The use of neutral di-Schiff base ligands, N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) and its analogues, N,N′-bis[1-(2-pyridyl)ethylidene]-1,2-diiminoethane (BPEE) and N,N′-bis(2-pyridylmethylidene)-trans-1,2-diiminocyclohexane (BPIC), as complexatIon reagents for Ion-Pair extractIon of divalent transitIon metal catIons into nitrobenzene with picrate anIon was investigated. The results of numerical analysis concerning the extractIon behavior indicated that they act as imine-N bidentate ligands in the extractIon system. Furthermore, the introductIon of the alkyl substituents onto imine-C on BPIE led to the change in the extractIon selectivity by steric distortIon of the catIonic complexes, whereas that onto ethylene-C only caused the enhancement of the extractability.
