T. Kawata

Bio: T. Kawata is an academic researcher from Meisei University. The author has contributed to research in topics: Liquid–liquid extraction & Pyrazolone. The author has an hindex of 1, co-authored 1 publications receiving 32 citations.

SYNERGISTIC EXTRACTION OF COPPER (II) AND OTHER DIVALENT METALS WITH 3-PHENYL-4-ACYLISOXAZOL-5-ONES AND 1-PHENYL-3-METHYL-4-ACYLPYRAZOL-5-ONES IN THE PRESENCE OF TRI-n-OCTYLPHOSPHINE OXIDE IN TOLUENE

Abstract: The synergistic extraction of copper (II) from 1M NaN03 aqueous solutions with acidic chelating extractants HL = 3-phenyl-4-acylisoxazol-5-ones (acyl = benzoyl, "HPBI", and p-tert-butylbenzoyl, "HPtbBI") and 1-phenyl-3-methyl-4-acylpyrazol-5-ones (acyl = benzoyl, “HPMBP”, p-tert-butylbenzoyl, “HPMtbBP” and stearoyl, "HPMSP"), in the absence and presence of trx-n-octylphosphine oxide (TOPO) in toluene at 25°0, has been studied. The TOPO-HL interaction, which is one order of magnitude stronger with 4-acylisoxazol-5-ones than with 4-acylpyrazol-5-ones, strongly influences the synergistic extraction efficiency. The extracted species are CuL2 and CuL2(T0P0). Because of their higher acidity, the extractions performed with 4-acylisoxazol-5-ones occur at a lower pH range than with 4-acylpyrazol-5-ones.

Synthesis and Spectral Studies of Octacoordinated Dioxouranium(VI) Complexes with Some Schiff Bases Derived from 4-Acetyl-2,3-Dimethyl-l-(4-Methylphenyl)-3-Pyrazoline-5-One and Aromatic Amines

Abstract: Eight new dioxouranium(VI) complexes with the neutral bidentate Schiff bases, L-L (where L-L is the Schiff base prepared from o-phenetidine, p-phenetidine, m-phenetidine, o-toluidine, m-toluidine, p-toluidine, 2,6-xylidine or 2,4-xylidine and 4-acetyl-2,3-dimethyl-l-(4-methylphenyl)-3-pyrazoline-5-one) have been synthesized by the reaction of ethanol solutions of dioxouranium(VI) nitrate hexahydrate and the Schiff base. The complexes, which have been characterized on the basis of elemental analyses, molar conductances, molecular weight determinations, magnetic measurements and infrared and electronic spectral studies, have the general formula [uo2(L-L)2(NO3)2]. In these complexes, the nitrate groups coordinate in a bidentate fashion and, hence, a coordination number of eight is assigned to the uranyl ion.

Extraction of uranium(vi) and vanadium(v) with 4-adipoyl and 4-sebacoyl derivatives of bis(1-phenyl-3-methyl-pyrazolone-5) and effect of decanol on the distribution behaviour of these metal ions

Abstract: The liquid-liquid extraction of U(VI) and V(V) with 4-adipoylbis(l-phenyl-3-methyl-pyrazolone-5) (H2AdP)′ and 4-sebacoylbis(l-phenyl-3-methyl-pyrazolone-5) (H2SP) was studied in the presence and absence of decanol (DOH). The studies show that in the absence of DOH the extracted species were (U02) 2(AdP) 2 U02(HSP) 2, V02(HAdP) and V02(HSP). Addition of DOH to the organic phase resulted in enhancement of the extraction of V(V) at high HCI concentrations but reduced the extraction of U(VI) due to a change in extraction mechanism. Subsequently, ion-pair complex species VO2(HAdP)DOH2 +)2CI- and V02(HSP)(DOH2 +)2.2CI- were extracted. The extraction constants Kcx and pH1/2 for the various extraction systems were determined and used for explaining the various extraction mechanisms observed.