Characteristics of industrial di(alkylphenyl)dithiophosphoric acids

Instrumental and classical methods have been used to characterize some industrial di(alkylphenyl)dithiophosphoric acids. The (31)P-NMR chemical shifts of di(nonylphenyl)dithiophosphoric acid and its derivatives are summarized.     

New approaches to the synthesis of aromatic polyesters

A new method of the synthesis of high molecular polybutylene terephthalate (PBT) is developed with the use of Irganox 1010, tris(nonylphenyl) phosphite and hypophosphite as stabilizers and boron nitride or boron oxide as a catalyst is proposed.     

Preparation of Eu-Doped Y(2)O(3) Luminescent Nanoparticles in Nonionic Reverse Microemulsions

In this study, Y(2)O(3):Eu luminescent nanoparticles were prepared by precipitation of aqueous yttrium nitrate/europium nitrate solution using ammonium hydroxide in the reverse microemulsions based on polyoxyethylene (5) nonylphenyl ether/polyoxyethylene (9) nonylphenyl ether, cyclohexane, and water. With Eu-doped Y(2)O(3) nanoparticles obtained, particle size, shape, chemical composition, crystalline formation rate, crystallinity, and photoluminescence were measured and compared with those of particles formed by a bulk precipitation method. The nanoparticles synthesized in microemulsion showed a narrow size distribution, spherical shape, fast crystalline formation rate, high crystallinity, and strong photoluminescence. This stronger photoluminescence of particles formed in a microemulsion might be attributed to more densely packed particles with very few voids and higher crystallinity at a relatively low temperature than those synthesized through a bulk precipitation method. Copyright 2000 Academic Press.     

Estimation of Distribution Parameters of Organic Solutes in Cloud Point Extraction

Cloud point extraction of aromatic solutes in the system containing nonionic surfactant polyoxyethylene nonylphenyl ether (PONPE 10) was discussed in terms of their hydrogen-bond donating and accepting abilities and hydrophobicity. It was shown that the Abraham model could be used to estimate the distribution ratio and the effect of aromatic solutes on the cloud point. Copyright 2000 Academic Press.     

Dissociation constants of organophosphinic acid compounds

The dissociation equilibria of di(2,4,4-trimethylpentyi) phosphinic acid, mono(2,4,4-trimethylpentyl) phosphinic acid, di(n-octyl)phosphinic acid and mono(n-octyl)phosphinic acid have been studied in ethanol-water mixtures by potentiometric titration at 25 degrees C. These data have been analysed both graphically numerically using the program LETAGROP-ZETA. The obtained pK(a) values have been correlated with the corresponding values in water, determined both indirectly by means of extraction measurements and by estimation using the suitable Hammett equation.     

Identification of an organic compound leached from a membrane filter

An organic compound leached from a Millipore HA filter has been identified as the non-ionic surfactant polyoxyethylene nonylphenyl ether with a degree of polymerization of 4-10 for the ethylene oxide unit. It is suggested that the Millipore HA filter should be used only after several rinses with sample or doubly-distilled water.     

Determination of tris(nonylphenyl) phosphite and nonylphenol in butadiene-styrene copolymers by high-performance liquid chromatography

A polar stationary phase high-performance liquid chromatography method was developed to determine the additives, tris(nonylphenyl) phosphite (TNPP) and the hydrolysis product, nonylphenol, in butadiene-styrene copolymers. Polymers were dissolved in cyclohexane, separated on a μPorasil stationary phase with a heptane/dichloro-methane mobile phase gradient, and detected by ultraviolet absorption at 280 nm. Typical relative standard deviations were 1.2% for TNPP and 2.0% for nonylphenol. Response was linear in the ranges 0–52 μg for TNPP and 0–29μg of nonylphenol.     

Poly（ethylene glycol）-supported Liquid-phase Parallel Synthesis of Di（aryloxyacetyl）thiosemicarbazides

An efficient poly(ethylene glycol) (PEG)-supported liquid-phase parallel approach to di(aryloxyacetyl)thiosemicarbazides is described. PEG-bound phenol reacted with chloroacetic acid to afford PEG-bound phenyloxyacetic acid, which was readily converted into corresponding phenyloxyacetyl chloride. Subsequent nucleophilic substitution with ammonium thiocyanate followed by addition of aryloxyacetic acid hydrazides gave PEG-bound di(aryloxyacetyl)thiosemicarbazides, which were easily cleaved to give the resulting library of 1-aryloxyacetyl-4-(4‘-methoxylcarbonylphenyloxyacetyl)thiosemicarbazides in good to high yield and high purity.     

Effect of diluents on the extractive capacity of organophosphoric acids in vanadium(V) recovery from sulfuric acid solutions

The extractive capacity of di(2-ethylhexyl)phosphoric and di(2,4,4-trimethylpentyl)phosphinic acids for vanadium(V) in its extraction from individual sulfuric acid solutions with the use of kerosene, a number of aliphatic alcohols, and octanone as diluents was studied. The most effective organic mixtures for extraction of vanadium(V) were determined in relation to the concentration of sulfuric acid.     

共吸附剂修饰TiO2薄膜电极

共吸附剂修饰纳晶TiO₂薄膜电极是目前染料敏化太阳电池研究的一个热点. 本文通过平带电势和电化学阻抗研究了二(3,3-二甲基丁基)次膦酸和鹅脱氧胆酸两种共吸附剂修饰对TiO₂薄膜电极的平带电势和电极表面钝化能力的影响及其在染料敏化太阳电池中的应用. 结果表明, 二(3,3-二甲基丁基)次膦酸能更有效地钝化TiO₂薄膜表面, 并使TiO₂薄膜平带电势负移. 电化学阻抗谱测试结果表明, 在染料敏化太阳电池中, 相对于鹅脱氧胆酸, 二(3,3-二甲基丁基)次膦酸能更显著地提高器件的电子寿命和开路电压.     

Preparation of hemispherical polymer particles via phase separation induced by microsuspension polymerization

Micrometer-sized, hemispherical polystyrene (PS) particles were successfully prepared by microsuspension polymerization of homogeneous styrene/hexadecane (HD) droplets dispersed in polyoxyethylene nonylphenyl ether (Emulgen 931) aqueous solution, followed by rapid removal of HD from formed PS/HD particles with a “Janus” structure. It was important for the formation of the morphology of Janus particles in thermodynamically stable state to carry out the polymerization slowly. The formation of by-product small PS particles by emulsion polymerization was suppressed by the additions of CuCl₂ as a water-soluble inhibitor and NaCl to decrease the solubility of styrene in the aqueous phase.     

Concentration of nonylphenol and its polyethoxylated derivatives by polymer-mediated extraction

Polymer-mediated extraction based on thermoresponsive precipitation of poly(N-isopropylacrylamide) [PNIPAAm] was applied to the concentration of amphiphilic compounds, nonylphenyl polyethoxylates (NPnEOs), in water. Among these nonionic surfactants, NPnEOs possessing the number, n, of ethoxy unit less than 5 were quantitatively recovered in polymer precipitates when a 0.100-g portion of PNIPAAm was used for a 10 ml sample solution. Torelance limit (30 ppm) against a typical industrial anionic surfactant, sodium dodecylsulfate, strongly suggests the potential to use the present method for practical purposes. After preconcentration, trace nonylphenol and mono-ethoxylated nonylphenol (ppb-level) in a river water sample were successfully determined by high-performance liquid chromatography with ultra-violet photometric detection.     

New Quinic Acid Derivatives from Hepatoprotective Inula crithmoides Root Extract

Fractionation directed by hepatoprotective activity of Inula crithmoides L. root resulted in the isolation of two new quinic acid derivatives, 3,5‐di‐O‐caffeoylquinic acid 1‐methyl ether ( I ; caffeoyl=(E)‐3‐(3,4‐dihydroxyphenyl)prop‐2‐enoyl; quinic acid=1,3,4,5‐tetrahydroxycyclohexanecarboxylic acid) and 4,5‐di‐O‐caffeoylquinic acid 1‐methyl ether ( II ), in addition to the well‐known hepatoprotective compound, 1,5‐di‐O‐caffeoylquinic acid ( III ). The hepatoprotective effect was indicated by the significant decrease in the level of four measured serum biochemical parameters (SGOT, SGPT, ALP, and bilirubin) in experimental rats. The structures of the isolated compounds were determined by analyses of 1D‐ and 2D‐NMR spectroscopic data.     

Iron Extraction with Di(2-Ethylhexyl)dithiophosphoric Acid and a Binary Extractant Based on It

Iron(III) extraction with trioctylmethylammonium di(2-ethylhexyl)dithiophosphate and di(2- ethylhexyl)dithiophosphoric acid was studied. It was shown that di(2-ethylhexyl)dithiophosphoric acid extracts iron in the form of the complex FeA₂, regardless of the oxidation state of iron in the initial aqueous solution. It was also shown that the iron(III) extraction with trioctylmethylammonium di(2-ethylhexyl)dithiophosphate over a wide acidity range occurs primarily to produce extractable substance (R₄N)FeCl₄; and at pH > 1, iron(II) dialkyldithiophosphate is also extracted into the organic phase. It was established that, in a system with a binary extractant, iron can be efficiently stripped from the organic phase with water or diluted solutions of mineral acids.     

Di(adamant-1-yl)- and di(adamant-2-yl)thiophosphoric acids and their triethylammonium salts in alkylation reactions

By reaction of di(adamant-1-yl) and di(adamant-2-yl) phosphites with sulfur in the presence of triethylamine diadamantylthiophosphoric acid triethylammonium salts were obtained. The latter by the action of hydrochloric acid were converted into free thiophosphoric acids and by the reaction of alkylation into the respective triesters which have thionic structure. Applicability in such reactions also of triethylammonium salts of diadamantyldithiophosphoric acids was demonstrated.     

Extraction of acetic acid by binary extractants

Interface distribution of acetic acid has been studied in systems with binary extractants, namely, trioctylmethylammonium di(2-ethylhexyl)phosphate, di(2-ethylhexyl)dithiophosphate, and dinonylnaphthalenesulfonate. It has been determined that, with the increase in the strength of the organic acid involved in a binary extractant, the extraction ability of a monocarboxylic acid decreases and addition reaction with the formation of extracted compound of R₄NA · HX_(o) composition becomes the dominant mechanism of extraction.     

A spectroscopic study of model urethanes

The synthesis, far infrared spectra, temperature-dependent mid-infrared spectra in the carbonyl and NH stretching regions and the Fourier transform Raman spectra are reported for polycrystalline samples of three small diurethanes, 1,3-phenyl di(carbamic acid methyl ester),2,6-toluene di(carbamic acid methyl ester) and 2,4-toluene di(carbamic acid methyl ester). An ab initio geometry optimization is reported for methyl N-phenyl carbamate using STO-3G and 3-21G basis sets, and for the three small diurethanes by molecular mechanics methods using the Dreiding I force field. The results suggest that, in isotropic surroundings, only a very small number of the 256 possible conformers of the urethane groups in the three small diurethanes contribute appreciably to the structure.     

Synthesis of di(adamantylalkyl) tosyloxymethylphosphonates and di(adamantyloxyalkyl) tosyloxymethylphosphonates

A simple method for the synthesis of esters of tosyloxymethylphosphonic acid based on the adamantane series of alcohols and diethyl tosyloxymethyl phosphonate was developed. The di(adamantylalkyl) and di(adamantyloxyalkyl) tosyloxymethylphosphonates are of interest as key compounds in the synthesis of antiviral drugs of the nucleoside phosphonate class.     

Investigation of the micropolarity in reverse micelles of nonionic poly(ethylene oxide) surfactants using 4-nitropyridine-N-oxide as absorption probe

The micropolarities of the reverse micelle (RM) interior of nonionic poly(ethylene oxide) surfactants of the alkyl ether type (poly(ethylene oxide)[4] lauryl ether (C12E4, Brij 30)), alkyl-aryl ethers (poly(ethylene oxide)[4] nonylphenyl ether (C9PhiE4), poly(ethylene oxide)[5] nonylphenyl ether (C9PhiE5), and poly(ethylene oxide)[5] octylphenyl ether (C8PhiE5)), and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers (Pluronics P123, F127) were investigated as a function of the water content by applying the absorption probe technique, using 4-nitropyridine-N-oxide (NP) as a probe. The change in the micellar aggregate micropolarity in different solvents (cyclohexane, decane, n-butanol, and n-butyl acetate) at various water contents has been investigated. The research was focused on the determination of the effects of surfactant structure and solvent type on the hydration degrees of the PEO chains in the region at the core limit, where the NP probe was located. All results regarding the polarities in RM and PEO/water calibration mixtures have been expressed in terms of Kosower's Z values, using the linear dependence of E(NP) on Kosower's Z. The PPO/butanol mixtures have also been used for RM in butanol as a reference system. The data revealed that local polarity in RM is dependent on the surfactant type, block copolymer composition, solvent nature, and water content. At the same water content, the results clearly indicate a lower hydration degree of triblock copolymers, as compared to the surfactants of the alkyl ether and alkyl-aryl ether type, but for P123 and F127 Pluronics in n-butanol the hydration is higher owing to the behavior of butanol as cosurfactant and to its hydration.     

Direct atom-efficient esterification between carboxylic acids and alcohols catalyzed by amphoteric, water-tolerant TiO(acac)2

A diverse array of oxometallic species were examined as catalysts for a test direct condensation of benzoic acid and 2-phenylethanol in 1:1 stoichiometry. Besides group IVB MOCl2-xH2O and TiOX2-xH2O, group VB VOCl2-xTHF and group IVB TiO(acac)2 were found to be the most efficient and water-tolerant catalysts for the test reaction. The new neutral catalytic protocol with the optimal TiO(acac)2 tolerates many stereo/electronic structural variations in both (di)acid (1 degree -3 degrees alkyl and aryl) and (di)alcohol (1 degree, 2 degrees alkyl, and aryl) components with high chemoselectivity.