A POSSIBLE USE OF PHOTO-REACTION IN LIQUID-LIQUID EXTRACTION OF SUBSTITUTION-INERT METAL COMPLEXES. EXTRACTION OF CHROMIUM(III) AND COBALT(III) COMPLEXES.

A liquid-liquid extraction of chromium(III) ion was achieved by a cooperative action of light (photoreduction) and conventional extractants on chromium(VI) species. The extraction of chromium spcies was studied by both molecular and atomic absorption spectrophotometry measurements. Trioctylphosphine oxide (TOPO) was the most effective among the extractants studied (TOPO, dibutylsulfoxide, tributyl phosphate, 2-ethyhexyl hydrogen 2-ethylhexylphosphonate, di (2,4,4-trimethylpentyl)-phosphinic acid). A back-extraction of chromium(III) species to aqueous solution was also promoted by photo-irradiation. The nature of the extraction system was studied under various operational conditions such as wavelength of illuminating light, coordinating ah ionic species in aqueous solution, and coexisting metal ions. A liquid- liquid (back-) extraction of some     

气-液-液喷射反应萃取制备过氧化氢的过程

引　言过氧化氢 (H2 O2 )是一种性能优良的氧化剂 ,因其以水为还原产物而备受绿色化学与化工研究领域广泛关注 .以过氧化氢为氧化剂的氧化过程具有反应条件温和、选择性高、无污染等优点 ,因此被广泛地用于纺织品和造纸的无氯漂白、化学合成、污水处理等领域 ,应用前景十分广阔 ,市场潜力非常大 .蒽醌衍生物自动氧化法 (AO )是过氧化氢的主要生产方法 ,基本原理是[1] :烷基取代的蒽醌 (主要是 2 乙基蒽醌 )和四氢蒽醌 (主要是四　氢 2 乙基蒽醌 )溶解在适当的溶剂中配制成工作液 ,循环交替氢化和氧化工作液 ,即工作液中的蒽醌与氢气反应…     

SYNERGISTIC EXTRACTION OF EUROPIUM(III) WITH BENZOIC ACID AND THENOYLTRIFLUOROACETONE

ABSTRACT

The solvent extraction of europium(III) into solutions of thenoyltrifluoroacetone and benzoic acid in cyclohexane, carbon tetrachloride, benzene, chloroform, pentachloroethane, and tetrachloroethane has been measured at 25°C. It has been found that the extracted species involve two types of adducts, EuA₃· HB and EuA₃· 2HB where A denotes the TTA anion and HB the benzoic acid monomer. The magnitude of the adduct formation constants in different solvents has been correlated with the dimerization constants of benzoic acid in the solvents.     

A STUDY OF COMPLEXES YIELDED BY HNO3 Fe(III)AND Eu(III) EXTRACTION FROM NITRATE MEDIA WITH ACIDIC Zr(IV) AND Hf( IV) DI-2-ETHILHEXYLPHOSPHATES

Possible reasons for significant enhancement of solvent extraction of some metals with dialkylphos-phoric acids in the presence of Zr(IV) and Hf(IV) are critically discussed, taking into consideration both the literature and the autors'data on the structure of acidic salts formed by these acids with Zr(IV) and Hf(IV). The chemistry of extraction of nitric acid, FeUII) and Eu ( I I I ) with Zr(IV) and Hf(IV) salts of di-2-ethy1hexy1 phosphoric acid (HX) has been studied using IR and ³¹P NMR spectroscopy. Nitric acid is extracted by these salts due to interaction with their acceptor sites that results in the formation of a new polymeric extractant with bidentate anions of two types, (X-H-X)- and (X-H-N0₃)_. Protons of these groups can be exchanged with metal cations extracted, e.g., with Fe(III) or Eu(I 11 ), heteropolynuc1 ear complexes with non-equivalent (chelating and bridge) N0₃ anions being formed during the extraction. The composition and structure of coordination polyhedrons formed around Zr(IV), Hf(IV), Fe(III) and Eu(III) have been determined. The reasons for a higher extraction ability of the salts studied for Fe(III) and Eu(III) versus D2EHPA itself are described.     

EXTRACTION OF EUROPIUM(III) ION WITH TETRAHEXYLMALONAMIDES

ABSTRACT

The extraction of europium(III) nitrate from sodium nitrate with a series of tetrahexylmalonamides has been investigated. The tetrahexylmalonamides considered were N.N.N’N’-tetrahexylmalonamide (THMA), N,N,N’N’-tetra-hexyl-2-methylmalonamide (MeTHMA), and N,N,N’N’-tetrahexyl-2,2-dimethy-lmalonamide (DiMeTHMA). This series allowed for a systematic determination of the effects of alkyl substitution of the methylene carbon. Equilibrium modeling of the extraction data indicates that the malonamide/Eu ratio in the extracted complexes is 3 for all three malonamides investigated. This stoichiometry is different than that determined for isolated complexes. This can be rationalized by the formation of complexes with monodentate-bound diamide ligands in the extracts. The extraction constant for Eu decreases by seven-fold in going from THMA to MeTHMA, and a precipitous drop in the extraction constant occurs upon substitution of a second methyl group on the methylene carbon (i.e., for DiMeTHMA).     

CHARACTERIZATION OF THE LANTHANUM(III) AND EUROPIUM(III) TRICHLOROACETATE COMPLEXES EXTRACTED WITH 18-CROWN-6

ABSTRACT

Extraction of lanthanide(III) ions with 18-crown-6 (18C6) and trichloroacetate (tea) has been studied. The composition, hydration, and structure of the La(III) and Eu(III) complexes extracted into 1,2-dichloroethane were investigated by using several methods such as the liquid-liquid distribution technique, conductimetry, Karl Fisher titration, laser luminescence spectroscopy, and ¹H NMR. The La(III) complex was found to be a monohydrate, La(tca)₃(18C6)(H₂O), while that of Eu(III) was a mixture of a monohydrate and a dihydrate, i.e., Eu(tca)₃(18C6)(H₂0) and Eu(tca)₃(18C6)(H₂0)₂- The origin of the selectivity by 18C6 which gives much higher extractability of La(III) than of Eu(III) is explained by considering the hydration and probable structure of their complexes.     

苯酚过氧化氢羟化过程的UV—Vis及ESR谱研究

运用UV－Vis手段考察了Dawson结构钼磷钒杂多化合物催化苯酚过氧化氢羟化过程中产物的分布,结合ESR波谱研究了羟化活性中心钒的价态变化情况。     

新型有机配合物Ni(diphos)(CO)_2的合成及其对苯的光羰化反应

通过Ｎｉ（ｄｉｐｈｏｓ）Ｃｌ２在ＣＯ气氛下被Ｎａ（Ｈｇ）还原,合成了４种新型Ｎｉ（ｄｉｐｈｏｓ）（ＣＯ）２配合物,其中ｄｉｐｈｏｓ：ｄＣｙｐＰｅ,ｄＣｙｈＰｅ,Ｐｈ（ｔ－Ｂｕ）Ｐｅ,ＰＰ。这４种配合物均通过红外光谱和元素分析等方法确认。利用上述合成的新型Ｎｉ的双羰基双膦配合物在室温和常压下,成功地进行了苯的光羰化反应性能研究,反应产物苯甲醛和苯甲醇均经色－质分析鉴定确认。结果表明,光反应与Ｒｈ（ｄｉｐｈｏｓ）（ＣＯ）Ｃｌ配合物一样都具有较高的选择性。此外,对光羰化反应的机理作了探索。     

EXTRACTION OF COPPER SALTS WITH A MIXED EXTRACTANT (III): AGGREGATION AND MOLECULAR STRUCTURE

A study of the extraction of copper salts from aqueous solutions into an equimolar solution of a long-chain amine and a long-chain carboxylic acid in toluene has shown that a cationic copper aggregate is formed in the organic phase. A mechanism of the extraction process and a model structure of the aggregate are proposed based on UV-visible, and NMR spectra, water solubilization, and computer-aided model design (CAMD).     

SYNERGISTIC SOLVENT EXTRACTION OF AM(III) AND EU(III) WITH THE SOFT DONOR TRIISOBUTYLPHOSPHINE SULFIDE AND THENOYLTRIFLUOROACETONE

The synergistic solvent extraction of Am(III) and Eu(III) with the neutral soft donor TIBPS and HTTA has been investigated using cyclohexane as the organic solvent and at an ionic strength of 0.1 M (NaCIO₄). The extracted species are [M(TTA)₂)] and [M(TTA)₂ (Clo₄) (TIBPS)] The extraction constants show that the synergistic factor is less than that for the analogous hard donor adducts (e.g., TBP and TOPO) and no preferential extraction of Am(III) over Eu(III) is observed.     

EFFECT OF ANIONS ON THERMODYNAMICS OF EXTRACTION OF Am(III) AND Eu(III) WITH OCTYL(PHENYL)-N,N-DIISOBUTYL-CARBAMOYLMETHYLPHOSPHINE OXIDE

The extraction of Am(III) and Eu(III) by octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in xylene from aqueous media containing 1.0 M NH₄NO₃, NH₄SCN, NH₄ClO₄ or a mixture of 0.3 M NH₄NO₃ + 0.7 M NH₄ClO₄ at pH 2.70 and at the temperatures of 15, 25, 35 and 45±0.1 °C has been studied. At all the temperatures, the species extracted were ML₃ · 3CMPO (M = Am(III) or Eu(III), L = NO₃ ^?, SCN^? or ClO₄ ^?) and M(NO₃)(ClO₄)₂ · 3CMPO. The thermodynamic parameters of the extraction reactions have been evaluated using the temperature coefficient method. The ?ΔG values follow the order SCN^? > NO₃ ^? + ClO₄ ^? > NO₃ ^? ≈ ClO₄ ^?, whereas the ?ΔH values an order NO₃ ^? + ClO₄ ^? > SCN^? > NO₃ ^? ≈ ClO₄ ^?. The effect of these anions on the thermodynamic parameters have been discussed employing compensation effects and also on the basis of the energy associated with the transfer of these anions from aqueous to the extractant phase.     

THERMODYNAMICS OF EXTRACTION OF Am(III) AND Eu(III) FROM NITRATE AND THIOCYANATE MEDIA WITH OCTYL(PHENYL)-N,N-DIISOBUTYLCARBAMOYLMETHYLPHOSPHINE OXIDE

ABSTRACT

The extraction of Am(III) and Eu(III) from 1.0 M NH₄NO₃ and NHS₄SCN at pH 2.60 into octyl(pheriyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in n-dodecane has been studied in the temperature range 15.0 to 45.0°C. Under all conditions, the species ML₃·CMPO is the dominant extracted complex. The extraction equilibrium constants are at least 10₃ higher in the SCN^- systems than in the NO₃ ^- systems. This difference is attributed to the relative energy associated with transfer of the anions from the aqueous to the: extractant phase. Extraction enthalpies and entropies have been calculated in each system from the temperature dependence of K_ex. Enthalpies are considerably more exothermic in the thiocyanate system for both metal ions. Comparison of ΔH_Am ^SCN with ΔH_EU ^SCN gives a possible indication of enhanced Am-SCN bond strength in the extracted complex.     

KINETIC STUDIES OF THE SOLVENT EXTRACTION OF PLATINUM(II) WITH DIPHENYLTHIOUREA

The race of extraction of plaCinum(II) wich diphenylthiourea (DPTU) into chloroform has been evaluated as a function of [DPTU]₀, [Cl] and the solution pH at 25° C. The homogeneous chemical reaction:

PtCl^? ₃ + DPTU → PtC1₃(DPTU)^?

is considered to be the rate determining step with a rate constant of 17.2 M^-1s^-1 The role of tetraheptylammonium chloride (THA^?,C1), thiourea (TU), thiocyanate, and iodide in catalyzing the extraction is examined.     

SEARCH FOH OPTIMUM CONDITIONS OF EXTRACTION OF METAL COMPLEXES WITH ALKYLIMIDAZOLES. III. STRUCTURE - EXTRACTABILITY RELATIONSHIPS FOR 1,4-DIMETHYLIMIDAZOLE COMPLEXES OF Co(II), Ni(II), Cu(II), Zn(II), AND Cd(II)

Stability constants of the 1,4-dimethylimidazole complexes of Co(II),Ni{II),Cu(II),Zn(II), and Cd(II) have been determined in aqueous solution and their structure has been elucidated. Conformational equilibria of the type octahedron-tetrahedron have been found in the case of the Co(II) and Sn(II) complexes. The extraction of all complexes has been shown to be dependent on their'molar contributions, d?n? expressed in per cent. The distribution constants have determined for each complex and the composition of the species extracted with organic solvent has been suggested.The measurements were run at 298?K, at the ionic strength of the aqueous phase of 0.5 maintained by means of KNO?3?.     

EXTRACTION AND SEPARATION OF LANTKANIDE METALS WITH 2-(3,5-DIBROMO-2-PYRIDYLAZO)-5-DIETHYLAMINOPHENOL

A study of the equilibrium extraction behavior of a series of representative tervalent lanthanide ions, La, Pr, Eu and Yb, was conducted using a CC1 solution containing either 2-( 3, 5-dibromo-2-pyridyxazo) -5-di-ethyl-aminophenol (DBPADAP or HL) alone or combined with TOPO. With HL,the lanthanides are extracted as simple chelates LnL?. In the presence of both HL and TOPO, the extracted species may be Ln(OH)L₂(TOPO).. Solvent extraction equilibrium constants of the lan-thanide-DBPADAP complexes are reported. the extractant, DBPADAP, displays good selectivity for the lighter lanthanides.     

SOLVENT EXTRACTION OF ZINC(II) ANIONIC g-DIKETONATE COMPLEXES AS ION-PAIRS WITH TETRABUTYLAMMONIUM IONS

Solvent extraction equilibria of zinc(II)with five 6-diketones(HA)in carbon tetrachloride-aqueous 1 mol dm^?3NaN0₃systems are studied in the absence and presence of tetrabutylammonium ions(tba⁺The distribution data of zinc(II)in the absence of tba+ are explained in terms of extractions of uncharged ZnA2 complex from the aqueous phase where the ZnA⁺, ZnA₂and ZnA₃complexes are formed, and those in the presence of tba+ in terms of extraction of the ZnA3~tba+ ion-pairs in addition to the uncharged one. The extraction of the ZnA³-tba⁺species is better with hexafluoroacetylacetone than with trifluoroacetyl-acetone. It is better when the extractant is benzoyltri-fluoroacetone than when it is trifluoroacetylacetone and this is explained in terms of a greater increase in the hydrofobic character by formation of the tris-complex from the bis-complex with the larger ligand. However, the extraction with acetylacetone and benzoylacetone is not affected by though the formation of the tris-chelate with these ligands in the aqueous phase is recognized from the extraction curves. No explanation can be given at the moment for the poor extractability of the most stable tris-complexes among those studied.     

新型有机配合物Rh(diphos)(CO)Cl的合成及其对苯的光羰化反应

利用［Ｒｈ（ＣＯ）２（μＣｌ）］２与ｄｉｐｈｏｓ反应，合成了３种新型Ｒｈ（ｄｉｐｈｏｓ）（ＣＯ）Ｃｌ配合物，其中ｄｉｐｈｏｓ＝ｄ（ｔＢｕ）Ｐｅ，ｄＣｙｈＰｅ，ｄＣｙｐＰｅ。这３种配合物均通过红外光谱和元素分析等方法测定确认。利用上述合成的新型Ｒｈ的羰基双膦配合物在室温和常压下，首次成功地进行了苯的光羰化反应性能的研究，反应产物苯甲醛和苯甲醇均经色质分析鉴定确认。结果表明，光反应都具有较高的选择性。同时对光羰化反应的机理作了合理的解释。     

MECHANISTIC STUDIES ON THE EXTRACTION OF PALLADIUM(II) WITH DIOCTYL SULPIDE

ABSTRACT The equilibrium and kinetics of the extraction of palladiura(II) ion with dioctyl sulfide (R-S) in chloroform have been studied at 25 C and an ionic strength of 1.0 M. The extracted species was found to be pdcl₂ (R₂S) and to have an extraction constant log K_ex. =9.84 The observed rate expression for the extraction:

-d[Pd]_T/dt = k [Pd]_T[R₂S]_o/[cl^-],

supports a mechanism in which the rate-determining step is the reaction of PdCl₃(H₂O) ^- with R₂ S in the aqueous phase.