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Sadanobu Inoue - One of the best experts on this subject based on the ideXlab platform.
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Synergistic Extraction of Lanthanides(III) by Mixtures of N‐p‐Methoxybenzoyl‐N‐phenylhydroxylamine and 1,10‐Phenanthroline
Solvent Extraction and Ion Exchange, 2006Co-Authors: Sadanobu Inoue, Qiangbin Zhang, Masayuki Uto, Hirotsugu MinamiAbstract:Abstract We conducted a study on the equilibrium extraction behavior of the trivalent lanthanide ions (M3+), La, Pr, Eu, Ho, and Yb, from tartrate aqueous solutions into chloroform solutions containing N‐p‐methoxybenzoyl‐N‐phenylhydroxylamine (Methoxy‐BPHA, HL) and 1,10‐phenanthroline (phen). The synergistic species extracted was found to be {ML2(phen) (HL)}+(1/2)Tar2−, where Tar2− is tartrate ion. The extraction constants were calculated. The extraction separation behavior and extractability of lanthanides are discussed in comparison with the self‐adducted chelate, ML3(HL)2, which was extracted in the absence of phen, and synergistic extraction by mixtures of other extractants such as 2‐thenoyltrifluoroacetone, and neutral donors.
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Solvent Extraction of Lanthanides(III) with N‐Cinnamoyl‐N‐phenylhydroxylamine and Its Trifluoromethyl Derivative
Solvent Extraction and Ion Exchange, 2004Co-Authors: Sadanobu Inoue, Qiangbin Zhang, Masayuki Uto, Hirotsugu MinamiAbstract:Abstract N‐m‐Trifluoromethylcinnamoyl‐N‐phenylhydroxylamine (CF3‐CPHA) was synthesized. The acid‐dissociation constant and distribution constant between chloroform and water of CF3‐CPHA and N‐cinnamoyl‐N‐phenylhydroxylamine (CPHA), which was the mother compound of CF3‐CPHA, were determined spectrophotometrically. The extraction behavior of tervalent lanthanides (Ln), Pr, Eu, and Yb into chloroform solution containing CPHA or CF3‐CPHA was studied. They are extracted as self‐adduct chelates, LnL3(HL)3, where L and HL denote the ligand anion and neutral ligand, respectively. The extraction constants and separation factors for the lanthanides with CPHA and CF3‐CPHA were evaluated. The extraction constant with CPHA are smaller than that obtained with CF3‐CPHA. However, it is observed that CPHA possesses higher selectivity than CF3‐CPHA.
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Solvent extraction of lanthanides(III) with N-p-phenylbenzoyl-N-Phenylhydroxylamine
Solvent Extraction and Ion Exchange, 2004Co-Authors: Sadanobu Inoue, Qiangbin Zhang, Masayuki UtoAbstract:Abstract N‐p‐Phenylbenzoyl‐N‐phenylhydroxylamine (phenyl‐BPHA) was newly synthesized. The acid‐dissociation constant and distribution constant between chloroform and 0.1 mol dm−3 potassium chloride solution of phenyl‐BPHA were spectrophotometrically determined. The solvent extraction of lanthanides(III) (Ln) with phenyl‐BPHA was investigated. The representative lanthanides (Yb, Ho, Eu, Pr, and La) were all found to extract with compounds as self‐adducts of the form, LnL3(HL)2, where L and HL denote the ligand anion and neutral ligand, respectively. The extraction constant and separation factor were compared with those of the other derivatives of N‐benzoyl‐N phenylhydroxylamine (BPHA) previously reported. As the results, it was found that the separation factors for lanthanides(III) pairs represented by Pr/Eu, Eu/Yb, and Pr/Yb, with phenyl‐BPHA have moderate values by the comparison of those of other hydroxamic acids and other extractants.
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Steric effect of substituents on the extraction of lanthanoids(III) with N-p-(n-, iso- and tert-)butylbenzoyl-N-Phenylhydroxylamine
Talanta, 1997Co-Authors: Sadanobu Inoue, Qiangbin Zhang, Masayuki UtoAbstract:Abstract N-p-(n-, iso- and tert-)Butylbenzoyl-N-Phenylhydroxylamine (HL) was synthesized to evaluate the steric effect of the substituent on the mutual extraction separation of representative lanthanoids(III) (Ln). Lanthanoids(III) were all found to be extracted with compounds as self-adducts of the form LnL3(HL)2. It was found that the structure of the substituents in N-p-butylbenzoyl-substituted N-Phenylhydroxylamine is closely related to the separation factor for the pair of Yb/Eu. The separation factors for a pair of Eu/Yb with these compounds decreased in the order of tert-butyl derivative>iso->n-, with a decreasing Taft's Es value, that is, with an increasing steric effect of the substituent group. The correlation between the separation factor and the stereochemical shape of the substituent was also investigated.
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SOLVENT EXTRACTION OF LANTHANIDES WITH N-m-NITROBENZOYL-AND N-m-CYANOBENZOYL-N-PHENYLHYDROXYLAMTNE
Solvent Extraction and Ion Exchange, 1995Co-Authors: Sadanobu InoueAbstract:ABSTRACT The solvent extraction of lanthanides (Ln) with N-m-nitrobenzoyl- and N-m-cyanobenzoyl-N-Phenylhydroxylamine, was investigated. The representative lanthanides (Yb, Ho, Eu, Pr and La) Here all found to extract with compounds as self-adducts of the form, LnL3(HL) 3, where L and HL denote die ligand anion and neutral ligand, respectively. The extraction constant and separation factor were compared with those of the N-p-octyloxy derivative bof N-benzoyl-N -phenylhydroxylamine previously reported. The correlation between extractability, mutual separability of lanthanides and acidity of the reagent were discussed.
Masayuki Uto - One of the best experts on this subject based on the ideXlab platform.
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Synergistic Extraction of Lanthanides(III) by Mixtures of N‐p‐Methoxybenzoyl‐N‐phenylhydroxylamine and 1,10‐Phenanthroline
Solvent Extraction and Ion Exchange, 2006Co-Authors: Sadanobu Inoue, Qiangbin Zhang, Masayuki Uto, Hirotsugu MinamiAbstract:Abstract We conducted a study on the equilibrium extraction behavior of the trivalent lanthanide ions (M3+), La, Pr, Eu, Ho, and Yb, from tartrate aqueous solutions into chloroform solutions containing N‐p‐methoxybenzoyl‐N‐phenylhydroxylamine (Methoxy‐BPHA, HL) and 1,10‐phenanthroline (phen). The synergistic species extracted was found to be {ML2(phen) (HL)}+(1/2)Tar2−, where Tar2− is tartrate ion. The extraction constants were calculated. The extraction separation behavior and extractability of lanthanides are discussed in comparison with the self‐adducted chelate, ML3(HL)2, which was extracted in the absence of phen, and synergistic extraction by mixtures of other extractants such as 2‐thenoyltrifluoroacetone, and neutral donors.
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Solvent Extraction of Lanthanides(III) with N‐Cinnamoyl‐N‐phenylhydroxylamine and Its Trifluoromethyl Derivative
Solvent Extraction and Ion Exchange, 2004Co-Authors: Sadanobu Inoue, Qiangbin Zhang, Masayuki Uto, Hirotsugu MinamiAbstract:Abstract N‐m‐Trifluoromethylcinnamoyl‐N‐phenylhydroxylamine (CF3‐CPHA) was synthesized. The acid‐dissociation constant and distribution constant between chloroform and water of CF3‐CPHA and N‐cinnamoyl‐N‐phenylhydroxylamine (CPHA), which was the mother compound of CF3‐CPHA, were determined spectrophotometrically. The extraction behavior of tervalent lanthanides (Ln), Pr, Eu, and Yb into chloroform solution containing CPHA or CF3‐CPHA was studied. They are extracted as self‐adduct chelates, LnL3(HL)3, where L and HL denote the ligand anion and neutral ligand, respectively. The extraction constants and separation factors for the lanthanides with CPHA and CF3‐CPHA were evaluated. The extraction constant with CPHA are smaller than that obtained with CF3‐CPHA. However, it is observed that CPHA possesses higher selectivity than CF3‐CPHA.
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Solvent extraction of lanthanides(III) with N-p-phenylbenzoyl-N-Phenylhydroxylamine
Solvent Extraction and Ion Exchange, 2004Co-Authors: Sadanobu Inoue, Qiangbin Zhang, Masayuki UtoAbstract:Abstract N‐p‐Phenylbenzoyl‐N‐phenylhydroxylamine (phenyl‐BPHA) was newly synthesized. The acid‐dissociation constant and distribution constant between chloroform and 0.1 mol dm−3 potassium chloride solution of phenyl‐BPHA were spectrophotometrically determined. The solvent extraction of lanthanides(III) (Ln) with phenyl‐BPHA was investigated. The representative lanthanides (Yb, Ho, Eu, Pr, and La) were all found to extract with compounds as self‐adducts of the form, LnL3(HL)2, where L and HL denote the ligand anion and neutral ligand, respectively. The extraction constant and separation factor were compared with those of the other derivatives of N‐benzoyl‐N phenylhydroxylamine (BPHA) previously reported. As the results, it was found that the separation factors for lanthanides(III) pairs represented by Pr/Eu, Eu/Yb, and Pr/Yb, with phenyl‐BPHA have moderate values by the comparison of those of other hydroxamic acids and other extractants.
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Steric effect of substituents on the extraction of lanthanoids(III) with N-p-(n-, iso- and tert-)butylbenzoyl-N-Phenylhydroxylamine
Talanta, 1997Co-Authors: Sadanobu Inoue, Qiangbin Zhang, Masayuki UtoAbstract:Abstract N-p-(n-, iso- and tert-)Butylbenzoyl-N-Phenylhydroxylamine (HL) was synthesized to evaluate the steric effect of the substituent on the mutual extraction separation of representative lanthanoids(III) (Ln). Lanthanoids(III) were all found to be extracted with compounds as self-adducts of the form LnL3(HL)2. It was found that the structure of the substituents in N-p-butylbenzoyl-substituted N-Phenylhydroxylamine is closely related to the separation factor for the pair of Yb/Eu. The separation factors for a pair of Eu/Yb with these compounds decreased in the order of tert-butyl derivative>iso->n-, with a decreasing Taft's Es value, that is, with an increasing steric effect of the substituent group. The correlation between the separation factor and the stereochemical shape of the substituent was also investigated.
Maxim R Ryzhikov - One of the best experts on this subject based on the ideXlab platform.
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on the catalytic transfer hydrogenation of nitroarenes by a cubane type mo3s4 cluster hydride disentangling the nature of the reaction mechanism
Physical Chemistry Chemical Physics, 2019Co-Authors: V S Safont, Ivan Sorribes, Juan Andres, Rosa Llusar, Monica Oliva, Maxim R RyzhikovAbstract:Cubane-type Mo3S4 cluster hydrides decorated with phosphine ligands are active catalysts for the transfer hydrogenation of nitroarenes to aniline derivatives in the presence of formic acid (HCOOH) and triethylamine (Et3N). The process is highly selective and most of the cluster species involved in the catalytic cycle have been identified through reaction monitoring. Formation of a dihydrogen cluster intermediate has also been postulated based on previous kinetic and theoretical studies. However, the different steps involved in the transfer hydrogenation from the cluster to the nitroarene to finally produce aniline remain unclear. Herein, we report an in-depth computational investigation into this mechanism. Et3N reduces the activation barrier associated with the formation of Mo–H⋯HOOCH dihydrogen species. The global catalytic process is highly exergonic and occurs in three consecutive steps with nitrosobenzene and N-Phenylhydroxylamine as reaction intermediates. Our computational findings explain how hydrogen is transferred from these Mo–H⋯HOOCH dihydrogen adducts to nitrobenzene with the concomitant formation of nitrosobenzene and the formate substituted cluster. Then, a β-hydride elimination reaction accompanied by CO2 release regenerates the cluster hydride. Two additional steps are needed for hydrogen transfer from the dihydrogen cluster to nitrosobenzene and N-Phenylhydroxylamine to finally produce aniline. Our results show that the three metal centres in the Mo3S4 unit act independently, so the cluster can exist in up to ten different forms that are capable of opening a wide range of reaction paths. This behaviour reveals the outstanding catalytic possibilities of this kind of cluster complexes, which work as highly efficient catalytic machines.
N. D. Pradeep Singh - One of the best experts on this subject based on the ideXlab platform.
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O-Alkyl-N-acyl-N-Phenylhydroxylamines as Photochemical Alkoxy Radical Precursors
Synthesis, 2012Co-Authors: Nilanjana Chowdhury, Anakuthil Anoop, N. D. Pradeep SinghAbstract:A simple and efficient technique for the photolysis of alkoxy radical precursors is developed. Irradiation of O -alkyl- N -acyl- N -phenylhydroxylamines, as representative alkoxy radical precursors, with ultraviolet light (≥254 nm) results in homolytic N–O bond cleavage to generate singlet alkoxy and acylaminyl caged radical pairs. These radicals, depending on the solvent employed, either escape from the cage to form fragmentation products, or undergo in-cage reactions to produce photorearrangement products. The homolytic cleavage of the N–O bond is analyzed using time-dependent density functional theory calculations. The nature of the N -acyl substituent on the O -alkyl- N -acyl- N -phenylhydroxylamines is shown to influence their ability to generate radicals. Furthermore, identification and trapping of the alkoxy radicals is demonstrated.
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N,O-diacyl-4-benzoyl-N-Phenylhydroxylamines as photoinduced DNA cleaving agents.
Bioorganic & medicinal chemistry letters, 2010Co-Authors: Nilanjana Chowdhury, Sansa Dutta, Boda Nishitha, Swagata Dasgupta, N. D. Pradeep SinghAbstract:Abstract Photoinduced homolytic fission of nitrogen–oxygen bond in N , O -diacyl-4-benzoyl- N -phenylhydroxylamines using ⩾310 nm UV light for 10 min produced acylaminyl and acyloxy radicals, which resulted in single strand cleavage of DNA at pH 7.0. Further the DNA cleaving ability of N , O -diacyl-4-benzoyl- N -phenylhydroxylamines found to depend both on its concentration and acyl substituents.
Michael Anthony Forth - One of the best experts on this subject based on the ideXlab platform.
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Organic Syntheses - N-Acetyl-N-Phenylhydroxylamine via Catalytic Transfer Hydrogenation of Nitrobenzene Using Hydrazine and Rhodium on Carbon
Organic Syntheses, 2003Co-Authors: P. W. Oxley, B. M. Adger, M. J. Sasse, Michael Anthony ForthAbstract:N-acetyl-N-Phenylhydroxylamine via catalytic transfer hydrogenation of nitrobenzene using hydrazine and rhodium on carbon solvent: 100 mL of petroleum ether product: N-acetyl-N-Phenylhydroxylamine Keywords: acylation; metal-catalyzed reactions, rhodium; reduction, NO2 NHOH; acetyl chloride, irritant; N-acetyl-N-Phenylhydroxylamine, potential carcinogen; hydrazine, toxicity; nitrobenzene, poison; nitrobenzene, poison; phenylhydroxylamine, carcinogen
