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Disordered materials with resilient and soft-templated functional units bear the potential to fill the pipeline of robust catalysts for renewable energy storage. However, for novel materials lacking long-range order, the ability to discern local structure with atomic resolution still pushes the boundaries of current analytical and modeling approaches. We introduce a two-pillar strategy to monitor the formation and unravel the structure of the first disordered onedimensional cobalt coordination polymer catalyst, Co-dppeO2. This target material excels through proven high performance in commercial alkaline electrolyzers and organic transformations. We demonstrate that the key architecture behind this activity is the unconventional embedding of hydrated {H2O-Co2(OH)2-OH2} edge-site motifs, nested into a flexible organic matrix of highly oxidized and bridging hydrophobic dppeO2 ligands. Our combination of in situ spectroscopy and computational modeling of X-ray scattering and absorption spectra, backed with complementary experimental techniques, holds the key to understanding the atomic-range structure of important disordered materials.

Disordered materials with resilient and soft-templated functional units bear the potential to fill the pipeline of robust catalysts for renewable energy storage. However, for novel materials lacking long-range order, the ability to discern local structure with atomic resolution still pushes the boundaries of current analytical and modeling approaches. We introduce a two-pillar strategy to monitor the formation and unravel the structure of the first disordered onedimensional cobalt coordination polymer catalyst, Co-dppeO2. This target material excels through proven high performance in commercial alkaline electrolyzers and organic transformations. We demonstrate that the key architecture behind this activity is the unconventional embedding of hydrated {H2O-Co2(OH)2-OH2} edge-site motifs, nested into a flexible organic matrix of highly oxidized and bridging hydrophobic dppeO2 ligands. Our combination of in situ spectroscopy and computational modeling of X-ray scattering and absorption spectra, backed with complementary experimental techniques, holds the key to understanding the atomic-range structure of important disordered materials.

Disordered materials with resilient and soft-templated functional units bear the potential to fill the pipeline of robust catalysts for renewable energy storage. However, for novel materials lacking long-range order, the ability to discern local structure with atomic resolution still pushes the boundaries of current analytical and modeling approaches. We introduce a two-pillar strategy to monitor the formation and unravel the structure of the first disordered onedimensional cobalt coordination polymer catalyst, Co-dppeO2. This target material excels through proven high performance in commercial alkaline electrolyzers and organic transformations. We demonstrate that the key architecture behind this activity is the unconventional embedding of hydrated {H2O-Co2(OH)2-OH2} edge-site motifs, nested into a flexible organic matrix of highly oxidized and bridging hydrophobic dppeO2 ligands. Our combination of in situ spectroscopy and computational modeling of X-ray scattering and absorption spectra, backed with complementary experimental techniques, holds the key to understanding the atomic-range structure of important disordered materials.

Hazra S., Hoshimoto Y., Ogoshi S.. N-Phosphine Oxide-Substituted Imidazolylidenes (PoxIms): Multifunctional Multipurpose Carbenes. Chemistry - A European Journal 23, 15238 (2017); https://doi.org/10.1002/chem.201703644., This article discusses the concept of N-heterocyclic carbenes (NHCs) equipped with more than one functional moiety, which allows using these NHCs for multiple purposes. A pioneering example for such NHCs is N-phosphine oxide-substituted imidazolylidenes (PoxIms), and their synthesis and strategic use are highlighted. The utility of PoxIms by far exceeds the conventional use as multidentate ligands for metal complexes on account of the synergetic functions of the carbene and the N-phosphine oxide group(s).

The geometries, energies, and nuclear magnetic resonance (NMR) chemical shifts of 3 bases (trimethylphosphine, trimethylamine, and trimethylphosphine oxide), their 3 protonated cations, and 15 hydrogen-bonded complexes (corresponding to the HF, HNC, HCN, HCCH, HO, and CHOH Brønsted acids) have been calculated at the B3LYP/6-311++G(d,p) level. The determination of hydrogen bond acidities by NMR is classically performed using the P chemical shifts MePO. This method is more reliable than the use of the N NMR chemical shifts of MeN. This work shows that the P NMR chemical shifts of MeP cannot be used. The raison of the difference between MeP on one hand and MePO and MeN on the other will be discussed.

A series of new imidophosphanes and phosphine oxides containing 3,3,4,4-tetramethylsuccinimidyl group were synthesized and characterized by 1H, 13C{1H} and 31P NMR spectroscopy, IR and MS. PhmPCln (m = 3 n, n = 3, 2, 1) reacted with 3,3,4,4-tetramethylsuccinimide (TH) and potassium 3,3,4,4-tetra methylsuccinimidate 1 to give corresponding PhmPTn. Molecular structures of products were established by single-crystal X-ray diffraction experiments. Attempts to prepare new imidophosphoranes by reactions of 1 with PhmPCln (m = 5 n, n = 4, 3, 2) resulted in phosphine oxides. In these reactions the phosphoryl group was formed and we characterized a by-product of this type of reaction.

A series of new imidophosphanes and phosphine oxides containing 3,3,4,4-tetramethylsuccinimidyl group were synthesized and characterized by 1H, 13C{1H} and 31P NMR spectroscopy, IR and MS. PhmPCln (m = 3 n, n = 3, 2, 1) reacted with 3,3,4,4-tetramethylsuccinimide (TH) and potassium 3,3,4,4-tetra methylsuccinimidate 1 to give corresponding PhmPTn. Molecular structures of products were established by single-crystal X-ray diffraction experiments. Attempts to prepare new imidophosphoranes by reactions of 1 with PhmPCln (m = 5 n, n = 4, 3, 2) resulted in phosphine oxides. In these reactions the phosphoryl group was formed and we characterized a by-product of this type of reaction.

The main constituent in the speiss formed during copper drossing in lead bullion refining, when the copper:sulphur ratio exceeds 3.5:1, is copper arsenide. Oxidative acid leaching of the speiss gives a solution from which copper can be recovered by electrowinning, if the arsenic is first removed. Solvent extraction was investigated as a technique for arsenic removal in a series of shakeout tests using Cyanex 923. Various extraction isotherms were determined. A positive correlation was found between arsenic recovery and acidity and extractant concentration. Copper was not co-extracted with arsenic., The main constituent in the speiss formed during copper drossing in lead bullion refining, when the copper:sulphur ratio exceeds 3.5:1, is copper arsenide. Oxidative acid leaching of the speiss gives a solution from which copper can be recovered by electrowinning, if the arsenic is first removed. Solvent extraction was investigated as a technique for arsenic removal in a series of shakeout tests using Cyanex 923. Various extraction isotherms were determined. A positive correlation was found between arsenic recovery and acidity and extractant concentration. Copper was not co-extracted with arsenic.

The copper solvent extraction-electrowinning process used at the Mount Gordon mine, North Queensland, produces a concentrated sulphuric acid tankhouse bleed. A solvent extraction process has been developed to recover sulphuric acid selectively using a branched long-chain aliphatic tertiary amine, tris(2-ethylhexyl)amine (TEHA), as extractant, Shellsol 2046 as diluent and octanol as modifier. Up to 90% of the sulphuric acid was recovered as a pure aqueous acid stream at a concentration of up to 130 g/l, which can be recycled to the tankhouse circuit. The raffinate's acid concentration was cut from 180 g/l to 18 g/l, reducing the environmental impact of waste disposal. Equilibrium data and simulation results were compared using an alternative extractant, CYANEX 923, a phosphine oxide; both extractants cold be used in the acid recovery process. Pilot scale investigations in a pulsed plate column with TEHA were used to scale the process for industrial application., The copper solvent extraction-electrowinning process used at the Mount Gordon mine, North Queensland, produces a concentrated sulphuric acid tankhouse bleed. A solvent extraction process has been developed to recover sulphuric acid selectively using a branched long-chain aliphatic tertiary amine, tris(2-ethylhexyl)amine (TEHA), as extractant, Shellsol 2046 as diluent and octanol as modifier. Up to 90% of the sulphuric acid was recovered as a pure aqueous acid stream at a concentration of up to 130 g/l, which can be recycled to the tankhouse circuit. The raffinate's acid concentration was cut from 180 g/l to 18 g/l, reducing the environmental impact of waste disposal. Equilibrium data and simulation results were compared using an alternative extractant, CYANEX 923, a phosphine oxide; both extractants cold be used in the acid recovery process. Pilot scale investigations in a pulsed plate column with TEHA were used to scale the process for industrial application.

Dedicated to Prof. Hans Hartl on the occassion of his 60th birthday The cationic thorium(IV) complexes [Th{Ph2P(O)CH2CH2P(O)Ph2}2(NO3)3]NO3 and [Th{Ph2P(O)NP(O)Ph2}3(dmso)2]NO3 have been synthesized by reactions of Th(NO3)4 · 5H2O with bis(diphenylphosphino)ethane dioxide, Ph2P(O)CH2CH2P(O)Ph2 (L1), or ammonium bis-(diphenylphosphoryl)amide, (NH4)[Ph2P(O)NP(O)Ph2] (NH4L2), and subsequent recrystallization from dimethyl sulfoxide. The products have been studied spectroscopically and by X-ray crystallography. The thorium atom is ten-co-ordinate in the [Th(L1)2(NO3)3]+ cation with a co-ordination sphere which does not meet one of the idealized polyhedra for ten-co-ordination. Th-O bonds have been found in the range between 2.342(3) (phosphine oxide) and 2.599(4) Å (nitrate). An eight-co-ordinate thorium atom is found in the [Th(L2)3(dmso)2]+ cation. The almost ideal square-antiprismatic environment of the metal is occupied by oxygen atoms with Th-O bond lengths between 2.363(6) and 2.392(11) Å.

Different variables which could the affect the solvent extraction systems were investigated: contact time, temperature, aqueous pH and metal and extractant mixture concentrations. It was found that the three mixtures extracted gold from more alkaline pH values better than the amine or the corresponding phosphine oxide individually. Extraction equilibrium was reached quickly (5-10 min) and increasing temperature decreased gold extraction. Evaluation of the change of enthalpy showed that the extraction was exothermic. Gold was extracted preferentially to other metal-cyano complexes and at alkaline pH values, suggesting that these extractant mixtures could be used to purify aurocyanide solutions. Gold could be stripped from loaded organic solutions using low ionic strength aqueous alkaline solutions as stripping media, but better results were obtained using NaCN solutions., Different variables which could the affect the solvent extraction systems were investigated: contact time, temperature, aqueous pH and metal and extractant mixture concentrations. It was found that the three mixtures extracted gold from more alkaline pH values better than the amine or the corresponding phosphine oxide individually. Extraction equilibrium was reached quickly (5-10 min) and increasing temperature decreased gold extraction. Evaluation of the change of enthalpy showed that the extraction was exothermic. Gold was extracted preferentially to other metal-cyano complexes and at alkaline pH values, suggesting that these extractant mixtures could be used to purify aurocyanide solutions. Gold could be stripped from loaded organic solutions using low ionic strength aqueous alkaline solutions as stripping media, but better results were obtained using NaCN solutions.

Partial contents: Fluorhydroxyapatites of Northern Europe and Their Thermal Transformations; Physical Properties of Calcium Phosphates Glasses with Various CaO/P2O5 Mole Ratios; Calcination of Negev Phosphorites and Possible Causes for Technological Problems; New Aspects of Solid State Transformation of Vanadium Phosphates Used as Catalysts for Selective Oxidation or Ammoxidation Reactions; The Solid-State NMR of P-S and P-Se Compounds - An Important Tool for the Structure Investigation; Qualitative and Quantitative Study of Various Forms of Phosphorous in Storm and Runoff waters in Toulouse (31) and Florensac (34), France; Novel Alkenyl Substituted Cyclophosphazenes for the Synthesis of Thermally Stable Polymers; Structural Chemistry of Non-Cyclic Phosphazenes; A Study of Synthesis and Thermal Properties of Cyclotriphosphazene-Containing Polyimides; New Organofunctional Cyclophosphazene Derivatives; Oligomeric Phosphate Esters as Flame Retardants; Flame Retardant Actions of Tris( 1 ,3-Dichloro-2-Propyl) Phosphate in Flexible Urethane Foam; The Novel Tetraaminophosphonium Ion - Structure, Chemical Bonding and Reactions; Enthalpies of Formation of Bond Energies of P(III) and As(III) Commpounds; Cation and Anion Stabilities of Low-Coordinated pi-Bonded Phosphorus Systems. An ab initio Quantum Chemical Investigation. p9 and 10, ADA310262

The study of metal extraction with impregnated resins prepared by adsorption of a bifunctional extractant, O-methyl-dihexyl-phosphine-oxide O'-hexyl-2-ethyl phosphoric acid into polymeric macroporous supports of Amberlite XAD2-type, is described. This is a possible technological alternative to solvent extraction and ion exchange. The application of these resins in the column process allows the efficient extraction of Zn(II), Cu(II) and Cd(II) and their elution with HCL solutions. For the three metal ions, enrichment factors of 10 could be otained in the elution step. The extraction kinetics of Zn(II), Cu(II) and Cd(II) from nitrate solutions was studied., The study of metal extraction with impregnated resins prepared by adsorption of a bifunctional extractant, O-methyl-dihexyl-phosphine-oxide O'-hexyl-2-ethyl phosphoric acid into polymeric macroporous supports of Amberlite XAD2-type, is described. This is a possible technological alternative to solvent extraction and ion exchange. The application of these resins in the column process allows the efficient extraction of Zn(II), Cu(II) and Cd(II) and their elution with HCL solutions. For the three metal ions, enrichment factors of 10 could be otained in the elution step. The extraction kinetics of Zn(II), Cu(II) and Cd(II) from nitrate solutions was studied.

It is concluded that the extraction power of the bifunctional extractant BL, adsorbed on Amberlite XAD 2, is greater than that of DEHPA and much greater than that of DEHPA-TOPO. The benefit is increased affinity for cadmium extraction with some sacrifice in selectivity for copper and zinc., It is concluded that the extraction power of the bifunctional extractant BL, adsorbed on Amberlite XAD 2, is greater than that of DEHPA and much greater than that of DEHPA-TOPO. The benefit is increased affinity for cadmium extraction with some sacrifice in selectivity for copper and zinc.

A number of hydrometallurgical and chemical processes involve the disposal of highly acidic bleed streams containing such metals as copper, nickel or chromium dissolved in sulphuric or hydrochloric acids. For sulphate solutions in particular, available reagents will not function as metal extractants at such high acidities and conventional solvent extraction cannot be used to recover these metals. An alternative approach is described which involves extracting the acid selectively with a liquid phosphine oxide, recovering the metals from the depleted and less acidic solution with customary reagents and recycling the acid. The concept is illustrated using the treatment of an acidic copper sulphate solution containing nickel impurity., A number of hydrometallurgical and chemical processes involve the disposal of highly acidic bleed streams containing such metals as copper, nickel or chromium dissolved in sulphuric or hydrochloric acids. For sulphate solutions in particular, available reagents will not function as metal extractants at such high acidities and conventional solvent extraction cannot be used to recover these metals. An alternative approach is described which involves extracting the acid selectively with a liquid phosphine oxide, recovering the metals from the depleted and less acidic solution with customary reagents and recycling the acid. The concept is illustrated using the treatment of an acidic copper sulphate solution containing nickel impurity.

Oxidation of macrocyclic phosphine oxide-dithioether 1 produces only the dl form of disulfoxide 2. This selectivity can be rationalized by comparing the crystal structures of starting material and product, and on the basis of VT NMR data, which suggest that the starting macrocycle is conformationally constrained in solution. Molecules containing multiple sulfoxide and/or phosphine oxide groups are of interest as potential hosts for cations and for neutral guests bearing multiple hydrogen bond donors. As part of our exploration of such systems, we have prepared macrocycle 1 and oxidized it to disulfoxide 2. We report here that this oxidation is selective, providing only the dl product; neither of the meso stereoisomers was detected. Structural data for starting material and product suggest that this selectivity results from the conformational preference of eleven-membered ring of 1.

(O)P(CH2CH2CN)3, rhombohedral, R3c, a = 13.501(4)A, c = 10.177(3)A (hexagonal setting), z = 6 Rho sub o = 1.297 g/cc, Rho sub c = 1.30 g/cc. The molecule has three-fold rotational symmetry along the P-O bond axis with a C-P-C angle of 106.43(12) deg. The P=O distance is 1.485(3)A.

Thiokol Chemical Corporation/Wasatch Division uses MAPO in the production of UF-2121 liner. Thiokol changed MAPO vendors and, therefore, qualification of the new source MAPO was required. Thiokol prepared specimens from the new source and also specimens from the original source which are to be used as the control material in the 10 year surveillance testing program. The specimens were transferred to Ogden ALC for testing and reporting of the data obtained. This report includes the test results for the first, second, third, fourth, and fifth time testing of the control and special specimens at Ogden ALC. In all instances, the mean data for the control and special specimens are well above the minimum requirements found in TWR-7857 A, Thiokol specimen data. Therefore, the capability of the liner from the new source material is expected to perform satisfactorily. (Author)

A new combination of bonding agents when employed in hydroxy-terminated polybutadiene propellant compositions yields greatly improved high temperature aging characteristics and greatly improved low temperature physical properties for the compositions. The combination or bonding agent system consists of MT4 (reaction product of 2.0 moles of tris 1(2 methylaziridinyl)phosphine oxide, 0.7 mole adipic acid, and 0.3 mode tartaric acid); HX752 (bis isophthaloyl 1(2 methyl)aziridine); and BIDE (butyliminodiethanol) in a weight percent range of the propellant composition of 0.10% to 0.20%, 0.10% to 0.20% and 0.02% to 0.05% respectively. (Author), Supersedes PAT-APPL-840 927-77.

Thiokol Chemical Corporation/Wasatch Division uses MAPO in the production of UF-2121 liner. Thiokol changed MAPO vendors and, therefore, qualification of the new source MAPO was required. Thiokol prepared specimens from the new source and also specimens from the original source which are to be used as the control material in the 10 year surveillance testing program. The specimens were transferred to Ogden ALC for testing and reporting of the data obtained. This report includes the test results for the first through the eighth time testing of the control and special specimens at Ogden ALC. Statistical analysis of the test data showed that the physical properties of the new source compared closely to the old source of UF-2121 liner specimens. In all instances, the mean data for the control and special specimens are well above the minimum requirements found in TWR-7857 REV A, Thiokol specimen data. Therefore, the capability of the linear from the new source material is expected to perform satisfactorily. (Author)

A new family of fluorocarbon polyether fluids were investigated. The results show that these fluids have potential for advanced lubricant and hydraulic fluid applications. The fluid class is thermally stable at 700 deg F, has good lubricating characteristics, and is nonflammable. A shortcoming of these fluids is their corrosive effect on ferrous and titanium alloys in oxidizing atmospheres above 500 deg F.

The mode of action of resins in preventing microbial degradation of cotton cellulose has been investigated using polymer forming fire retardants. Compounds were selected that either react chemically with cellulose or polymerize within cotton fibers without any appreciable linkage between resin and cellulose. With these compounds it was possible to test whether resins mechanically block cellulolytic enzymes through formation of a polymeric barrier at a supra molecular level or whether chemical linkage between the polymer and cellulose is necessary at the molecular level to block susceptible sites on the cellulose molecule. Using enzyme degradation and soil burial techniques, it was shown that both forms of resins protect cotton cellulose in the form of sateen fabric or as cotton sliver., Microbiological Deterioration no. 12.

The present Technical Report No. V, on the work done under the subject contract, covers the quarter June 1 to August 31, 1950. During this period the synthesis and bench scale evaluation of bis-phosphorus compounds have been emphasized in view of the promising leads disclosed during the first year of work. A few preparations have been repeated either because of anomolous early results or because of desire to investigate certain materials further. Attention is now being given to preparative methods amenable to handling in larger scale to provide samples for Motor Laboratory testing and more comprehensive bench scale evaluation. In particular the testing of products not purified by distillation to avoid the need for tedious molecular distillations, is underway. The total numbers of compounds produced this quarter are as follows: phosphine oxides, 1 (total for five quarters, 10); phosphinates, 5 (19); phosphonates, 14 (35, of which 2 are repeats); phosphates 2 (2); miscellaneous (usually as intermediates in preparative procedures), 5 (10); grand total, 27 (76).

The electrochemical reductions and oxidations of organic phosphines, phosphine oxides, and phosphates have been investigated and mechanisms proposed in several cases. It is found that many of the organophosphorous compounds undergo electrode reactions to yield species that are very reactive and hense undergo a cleavage reaction or a following chemical reaction which may be catalytic in nature. Of the compounds investigated bis-(p-nitrophenyl) phosphate and triphenyl-n-butyl phosphonium iodide have shown definite tendency to cleave on reduction, whereas, some others, such as, tris-(pentafluorophenyl) phosphine, diphenyl pentafluorophenyl phosphine, pentafluorobenzene, and decafluorophenyl phosphine oxide undergo reduction with the parent compound regenerated by a following chemical reaction. (Author)

Brief summaries are presented on stereochemical research on the following topics: Synthesis and configuration of phosphine oxides; Hexachlorodisilane: A novel reducing agent for organic oxides and sulfides; Optical purity of phosphines by NMR; Pseudorotation and the stereochemistry of displacement reactions; Stereomutation of phosphine oxides by lithium aluminum hydride; Optical rotatory power; (2,3)-Sigmatropic rearrangements; and Energy barriers in pyramidal inversion process.

Theoretical reasons are advanced for the selection of compounds based on O, N, Si, C, S, and P as coordi ating agents capable of yielding thermally stable chelates. There are no C-to-C bonds in he chelate rings that might be formed by the compounds based on O-S-C-N, O-S-C-S-O, O-Si-C-N, O-Si-O-Si-O, O-Si-C-Si-O, O-Si-C-P-O, O-P-C-N, and O-P-C-P-O patterns selected for investigation. Initial results indicate that the O-P-C-N and O-P-C-P-O patterns are the most promising. T HE AB-type ligands NH2CH2P(O)(OH)R (where R is Me or Ph) and Ph2P(O)CH2P(O)(OH)Ph were synth sized and found to coordinate readily with Zn, yielding chelates with better stability than completely organic AB-type ligands. Other compounds prepared as potential ligands include NH2CH2SO3H, PhCH2SOCH2SOCH2Ph, Me2Si(OH)OSi(OH)Me2, Me2Si(OEt)CH2Si(OEt)Me2, Me2Si(OH)CH2Si(OH)Me2, NH2CH(Ph)P(O)(OH)2, NH2CH2P(O)(OH)2, NH2C(O)P(O)(OH)R (where R is M E OR Ph), and N2CH2P(O)Ph2. (Author)

The preparation of the comple es VO(ClO4)2. 5C5H5NO, VOCl2.2(C6H5)3PO, VO(ClO4)2.4(C6H5)3PO VOCl2.4(C6H5)3 sO, VO ClO4)2.4(C6H5)3 sO, and VOCl2.3(CH3)2SO are reported. Arguments for structural assumptions are based upon measurements of their visible and infrared spec ra, mag etic om s co uc c i pol r solvents. ( u hor)

An infrared method for the rapid screening of candidate catalysts for the polymerization of APO is described. Of the wide variety of chemicals screened, compounds that are acidic under curing conditions are the most effective catalysts. One of these catalysts, diammonium phosphate, combined with APO produces a new durable flame retardant for cellulosic textilium radicals, Ammonhosphoadicals, Phosphates, Imines, Phosphate coat ings, Infrared spectroscopy, Polymers.An infrared method for the rapid screening of candidate catalysts for the polymerization of APO is described. Of the wide variety of chemicals screened, compounds that are acidic under curing conditions are the most effective catalysts. One of these catalysts, diammonium phosphate, combined with APO produces a new durable flame retardant for cellulosic textilium radicals, Ammonium radicals, Phosphates, Imines, Phosphate coat ings, Infrared spectroscopy, Polymers.An infrared method for the rapid screening of candidate catalysts for the polymerization of APO is described. Of the wide variety of chemicals screened, compounds that are acidic under curing conditions are the most effective catalysts. One of these catalysts, diammonium phosphate, combined with APO produces a new durable flame retardant for cellulosic textiles. (Author)

Extractants of the T-I-MHPO and POR types are shown to be promising for the selective extraction of palladium (II) from nitrate solutions containing silver, zinc, copper, iron and antimony nitrates., Extractants of the T-I-MHPO and POR types are shown to be promising for the selective extraction of palladium (II) from nitrate solutions containing silver, zinc, copper, iron and antimony nitrates.

The redox processes taking place in the organic phase during cobalt extraction with the mixtures of bis(2,4,4-trimethylpentyl)dithiophosphinic acid (HR, CYANEX 301) and trioctyl phosphine oxide (TOPO, CYANEX 921) have been studied. It was shown that CoR2 stabilisation by the phosphine oxide prevents cobalt oxidation with air oxygen as well as with the disulfide of bis(2,4,4-trimethylpentyl)dithiophosphinic acid (R-R). The introduction of TOPO into the extract containing Co(III) dithiophosphinate results in an increase in the rate of cobalt reduction to Co(II). Analysis of the interphase cobalt distribution as well as of the IR and electronic absorption spectra of the extracts showed that cobalt forms a pentacoordinated tetragonal-pyramidal high-spin complex with the dithiophosphinate ions and TOPO with a tetragonal-pyramidal geometry. The base of the pyramid is made up of sulfur atoms while an oxygen atom is on the top. The composition of the complex was found to be CoR2·TOPO. Examples of the possible use of the CYANEX 301 and trialkyl phosphine oxide (TAPO, CYANEX 923) mixtures in cobalt extraction technology are given. (Authors.), The redox processes taking place in the organic phase during cobalt extraction with the mixtures of bis(2,4,4-trimethylpentyl)dithiophosphinic acid (HR, CYANEX 301) and trioctyl phosphine oxide (TOPO, CYANEX 921) have been studied. It was shown that CoR2 stabilisation by the phosphine oxide prevents cobalt oxidation with air oxygen as well as with the disulfide of bis(2,4,4-trimethylpentyl)dithiophosphinic acid (R-R). The introduction of TOPO into the extract containing Co(III) dithiophosphinate results in an increase in the rate of cobalt reduction to Co(II). Analysis of the interphase cobalt distribution as well as of the IR and electronic absorption spectra of the extracts showed that cobalt forms a pentacoordinated tetragonal-pyramidal high-spin complex with the dithiophosphinate ions and TOPO with a tetragonal-pyramidal geometry. The base of the pyramid is made up of sulfur atoms while an oxygen atom is on the top. The composition of the complex was found to be CoR2·TOPO. Examples of the possible use of the CYANEX 301 and trialkyl phosphine oxide (TAPO, CYANEX 923) mixtures in cobalt extraction technology are given. (Authors.)

A mixture of Triton X100 and novel dialkyl(diaryl) 2-hydroxyphenyl alkenyl phosphine oxide and dalkyl(diaryl) (2-methyl-4-oxopent-2-yl) phosphine oxide derivatives has been optimised for the extraction of lanthanide ions La(III), Gd(III) and Lu(III) from rather acidic media at pH 1 with the use of temperature-induced phase separation in mild conditions. Both the extraction efficiency and selectivity have been analysed for the wide range of phosphine oxide derivatives with hydroxyl, methoxyl or carbonyl group of the various structure and hydrophobicity. The obtained results indicate that both the efficiency and selectivity of micellar extraction are greatly affected by the electron donor capacity of P=O group, which in turn is affected by the length of the hydrophobic substituents neighbouring to the P=O group from n-C4H9 to n-C8H17. No effect of the aryl substituents has been found. Though all studied chelating agents exhibit enhanced extractability towards La(III) ions, their extraction selectivity is worst for the most efficient chelating agent and vice versa. It has been found that the high hydrophilicity of phosphine oxides does not restrict their use as chelating agents, though they provide less efficient extraction than their more hydrophobic counterparts. Advantages of the developed extraction procedure over the well-known liquid-liquid extraction technique are the absence of the so-called third phase and high concentration (ten-fold and more) of the extracted lanthanides within the surfactant-rich phase., A mixture of Triton X100 and novel dialkyl(diaryl) 2-hydroxyphenyl alkenyl phosphine oxide and dalkyl(diaryl) (2-methyl-4-oxopent-2-yl) phosphine oxide derivatives has been optimised for the extraction of lanthanide ions La(III), Gd(III) and Lu(III) from rather acidic media at pH 1 with the use of temperature-induced phase separation in mild conditions. Both the extraction efficiency and selectivity have been analysed for the wide range of phosphine oxide derivatives with hydroxyl, methoxyl or carbonyl group of the various structure and hydrophobicity. The obtained results indicate that both the efficiency and selectivity of micellar extraction are greatly affected by the electron donor capacity of P=O group, which in turn is affected by the length of the hydrophobic substituents neighbouring to the P=O group from n-C4H9 to n-C8H17. No effect of the aryl substituents has been found. Though all studied chelating agents exhibit enhanced extractability towards La(III) ions, their extraction selectivity is worst for the most efficient chelating agent and vice versa. It has been found that the high hydrophilicity of phosphine oxides does not restrict their use as chelating agents, though they provide less efficient extraction than their more hydrophobic counterparts. Advantages of the developed extraction procedure over the well-known liquid-liquid extraction technique are the absence of the so-called third phase and high concentration (ten-fold and more) of the extracted lanthanides within the surfactant-rich phase.

The extraction ability of a number of acetyl-containing phosphine oxides R2P(O)Me2CH2C(O)Me was studied relative to La(III), Nd(III), Ho(III) and Yb(III) in nitric acid. Comparison of extraction properties of acetyl-containing phosphine oxides and carbamoyl phosphine oxides, Ph2P(O)CH2C(O)NBu2, shows that acetyl-containing phosphine oxides extract trivalent lanthanides from 2 mol/l nitric acid much more efficiently than reference ligand diphenyl dibutyl methyl carbamoyl phosphine oxide. The highest selectivity for separation of heavy-light pairs of lanthanides are exhibited by acetyl-containing phosphine oxides with the longest-chain radicals at the P atom. Replacement of alkyl substituents at the P atom on phenyl one leaves the efficiency and selectivity of the extraction virtually unchanged, in contrast to the sharp increase in the efficiency at such a replacement in the case of reagents forming chelate complexes with extracted metals. As a consequence it can be assumed that the investigated acetyl-containing phospine oxides at extraction of lanthanides from 2 mol/l nitric acid act as monodentate extractants. However, unlike the well-known monodentate phosphoryl-containing substances that successfully extract trivalent lanthanides only at high concentrations of nitric acid, 5 mol/l and above, the acetyl-containing phosphine oxides effectively extract lanthanides even from 2 mol/l nitric acid. Increasing the length of the alkyl radical at phosphorus atom (increase of the ligand lipophilicity) increases the selectivity of the extractant for pairs of heavy and light lanthanides., The extraction ability of a number of acetyl-containing phosphine oxides R2P(O)Me2CH2C(O)Me was studied relative to La(III), Nd(III), Ho(III) and Yb(III) in nitric acid. Comparison of extraction properties of acetyl-containing phosphine oxides and carbamoyl phosphine oxides, Ph2P(O)CH2C(O)NBu2, shows that acetyl-containing phosphine oxides extract trivalent lanthanides from 2 mol/l nitric acid much more efficiently than reference ligand diphenyl dibutyl methyl carbamoyl phosphine oxide. The highest selectivity for separation of heavy-light pairs of lanthanides are exhibited by acetyl-containing phosphine oxides with the longest-chain radicals at the P atom. Replacement of alkyl substituents at the P atom on phenyl one leaves the efficiency and selectivity of the extraction virtually unchanged, in contrast to the sharp increase in the efficiency at such a replacement in the case of reagents forming chelate complexes with extracted metals. As a consequence it can be assumed that the investigated acetyl-containing phospine oxides at extraction of lanthanides from 2 mol/l nitric acid act as monodentate extractants. However, unlike the well-known monodentate phosphoryl-containing substances that successfully extract trivalent lanthanides only at high concentrations of nitric acid, 5 mol/l and above, the acetyl-containing phosphine oxides effectively extract lanthanides even from 2 mol/l nitric acid. Increasing the length of the alkyl radical at phosphorus atom (increase of the ligand lipophilicity) increases the selectivity of the extractant for pairs of heavy and light lanthanides.

Cyanex 923 may be used in the extraction of mineral acids from aqueous solutions. The great advantage of this extractant is that it is a liquid and thus its concentration can easily be adapted to any particular acid extraction system. The choice of toluene or dodecane as organic diluent does not seem to affect the extraction, although the use of aliphatic diluents should be avoided with sulphuric acid concentrations higher than 3 M and with perchloric acid due to third phase formation. The extraction mechanism can be related to solvation of the acid and formation the L.HmX species in the organic phase, where L is the extractant and m = 1, 2 or 3. The exception to this rule is nitric acid; IR measurements showed that in this case the extracted species are better represented by the general stoichiometry R3POHONO2; also, and only in the case of nitric acid, the extraction of an additional mole of acid at high initial HNO3 concentrations was detected. Increasing temperature decreases the extraction of the mineral acids except in the case of nitric acid, extraction of which slightly increases with temperature., Cyanex 923 may be used in the extraction of mineral acids from aqueous solutions. The great advantage of this extractant is that it is a liquid and thus its concentration can easily be adapted to any particular acid extraction system. The choice of toluene or dodecane as organic diluent does not seem to affect the extraction, although the use of aliphatic diluents should be avoided with sulphuric acid concentrations higher than 3 M and with perchloric acid due to third phase formation. The extraction mechanism can be related to solvation of the acid and formation the L.HmX species in the organic phase, where L is the extractant and m = 1, 2 or 3. The exception to this rule is nitric acid; IR measurements showed that in this case the extracted species are better represented by the general stoichiometry R3POHONO2; also, and only in the case of nitric acid, the extraction of an additional mole of acid at high initial HNO3 concentrations was detected. Increasing temperature decreases the extraction of the mineral acids except in the case of nitric acid, extraction of which slightly increases with temperature.

Extraction was studied as a function of several variables including temperature, diluent aromaticity, ionic strength of various inorganic salts added to the solution, and extractant concentration. Gold(I) stripping was accomplished effectively using low aqueous ionic strength solutions and high temperatures. Results showed that Me+...Au((CN)2)-.3R3PO is extracted into the aqueous phase, where Me+ represents the inorganic salt cation and R3PO is the phosphine oxide. The extracted species is probably solvated by water., Extraction was studied as a function of several variables including temperature, diluent aromaticity, ionic strength of various inorganic salts added to the solution, and extractant concentration. Gold(I) stripping was accomplished effectively using low aqueous ionic strength solutions and high temperatures. Results showed that Me+...Au((CN)2)-.3R3PO is extracted into the aqueous phase, where Me+ represents the inorganic salt cation and R3PO is the phosphine oxide. The extracted species is probably solvated by water.

The effect of several process variables, such as equilibration time, temperature, diluent aromaticity, extractant concentration and ionic strength of the aqueous phase was investigated. An IR spectroscopy study showed that the Au(CN)2 ionic complex and the extractant did not form a discrete compound, indicating that extraction was by a solvation mechanism. Results showed that the phosphine oxide could effectively extract gold(I) cyanide from alkaline solutions. Stripping was accomplished by aqueous solutions of low ionic strength and enhanced by high temperatures., The effect of several process variables, such as equilibration time, temperature, diluent aromaticity, extractant concentration and ionic strength of the aqueous phase was investigated. An IR spectroscopy study showed that the Au(CN)2 ionic complex and the extractant did not form a discrete compound, indicating that extraction was by a solvation mechanism. Results showed that the phosphine oxide could effectively extract gold(I) cyanide from alkaline solutions. Stripping was accomplished by aqueous solutions of low ionic strength and enhanced by high temperatures.

© 2016 Elsevier LtdA new two-step synthesis of phosphonium salts from phosphine oxides using Grignard reagents is reported. This approach involves a cyclization of Z-dialkyl-(diaryl)[2-(5-chloro-2-hydroxyphenyl)-2-phenylvinyl]phosphine oxides under the action of sulfinyl chloride with the formation of 2,2-dialkyl(diaryl)-6-chloro-4-phenyl-2H-1,2-benzoxaphosphinin-2-ium chlorides followed by ring opening under the action of organomagnesium compounds. The method was successfully applied to prepare a series of a new phosphonium salts bearing phenolic moiety with a wide range of substituents at phosphorus atom. Synthesized phosphonium salts shows high antibacterial and antifungal in vitro activity and low toxicity towards human red blood cell.

© 2016 Elsevier LtdA new two-step synthesis of phosphonium salts from phosphine oxides using Grignard reagents is reported. This approach involves a cyclization of Z-dialkyl-(diaryl)[2-(5-chloro-2-hydroxyphenyl)-2-phenylvinyl]phosphine oxides under the action of sulfinyl chloride with the formation of 2,2-dialkyl(diaryl)-6-chloro-4-phenyl-2H-1,2-benzoxaphosphinin-2-ium chlorides followed by ring opening under the action of organomagnesium compounds. The method was successfully applied to prepare a series of a new phosphonium salts bearing phenolic moiety with a wide range of substituents at phosphorus atom. Synthesized phosphonium salts shows high antibacterial and antifungal in vitro activity and low toxicity towards human red blood cell.

This article discusses the concept of N-heterocyclic carbenes (NHCs) equipped with more than one functional moiety, which allows using these NHCs for multiple purposes. A pioneering example for such NHCs is N-phosphine oxide-substituted imidazolylidenes (PoxIms), and their synthesis and strategic use are highlighted. The utility of PoxIms by far exceeds the conventional use as multidentate ligands for metal complexes on account of the synergetic functions of the carbene and the N-phosphine oxide group(s)., Hazra S., Hoshimoto Y., Ogoshi S.. N-Phosphine Oxide-Substituted Imidazolylidenes (PoxIms): Multifunctional Multipurpose Carbenes. Chemistry - A European Journal 23, 15238 (2017); https://doi.org/10.1002/chem.201703644.

Hazra S., Hoshimoto Y., Ogoshi S.. N-Phosphine Oxide-Substituted Imidazolylidenes (PoxIms): Multifunctional Multipurpose Carbenes. Chemistry - A European Journal 23, 15238 (2017); https://doi.org/10.1002/chem.201703644., This article discusses the concept of N-heterocyclic carbenes (NHCs) equipped with more than one functional moiety, which allows using these NHCs for multiple purposes. A pioneering example for such NHCs is N-phosphine oxide-substituted imidazolylidenes (PoxIms), and their synthesis and strategic use are highlighted. The utility of PoxIms by far exceeds the conventional use as multidentate ligands for metal complexes on account of the synergetic functions of the carbene and the N-phosphine oxide group(s).