Octylphosphinic acid

Figure 11-10. Comparison of organic phosphates, phosphonates and phos-phinates as lubricant additives. Four-ball test 60 minutes, 15 kg load, 1500 rpm. 4 mmoles of additive per 100 gm of white oil solution. Neutral esters o. Acids or acid esters A. 1 n-Butyl di-n-butylphosphinate. 1 Di-n-hexylphosphinic acid, la Di-n-octylphosphinic acid. 2 Di-n-butyl n-hexylphosphonate. 3 Di-n-butyl phenylphosphonate. 4 Tri-n-butyl phosphate. 4 Di-n-butyl phosphate. 5 Diethyl benzyIphosphonate. 6 Diethyl o-nitrophenylphosphonate. 7 Di(2-ethylhexyl) phosphate. 8 Dilauryl phosphate. 9 Tricresyl phosphate. From data by Forbes and Silver [40] and by Forbes and Battersby [46].

Tri-n-octylphosphine oxide [78-50-2] M 386.7, m 59.5-60°, pK jt <0. Mason, McCarty and Peppard [J Inorg Nuclear Chem 24 967 7962] stirred an O.IM solution in benzene with an equal volume of 6M HCl at 40° in a sealed flask for 48h, then washed the benzene solution successively with water (twice), 5% aq Na2C03 (three times) and water (six times). The benzene and water were then evaporated under reduced pressure at room temperature. Zingaro and White [J Inorg Nucl Chem 12 315 7960] treated a pet ether solution with aqueous KMn04 (to oxidise any phosphinous acids to phosphinic acids), then with sodium oxalate, H2SO4 and HCl (to remove any manganese compounds). The pet ether solution was slurried with activated alumina (to remove phosphinic acids) and recrystd from pet ether or cyclohexane at -20°. It can also be crystd from EtOH. 

Kopping JT, Patten TE (2008) Identification of acidic phosphorus-containing ligands involved in the surface chemistry of CdSe nanoparticles prepared in tri-n-octylphosphine oxide solvents. J Am Chem Soc 130 5689-5698... 

Figure 10.3 shows a Co nanoparticle deposition prior to SiNW growth. The average size of the nanoparticles used in this deposition was 12 nm. The standard deviation was 5 nm. As shown in Fig. 10.3, no individual nanoparticles were detected by SEM. The nanoparticles were embedded in large amounts of organic solvents or hydrocarbons such as oleic acid (OA) and tri-octylphosphine oxide (TOPO). 

Liquid membrane enrichment coupled on-line with ion chromatography. Low molecular mass carboxylic acids in low concentrations in air or soil samples can be determined by ion chromatography coupled on-line to a selective enrichment system consisting of a supported liquid membrane, impregnated with tri- -octylphosphine oxide in di-n-hexyl ether [97-98]. The system allows the determination of these carboxylic acids at micromolar levels in the presence of interfering ions such as nitrite, chloride, sulfate, iron, and aluminum. 

To a solution of Fmoc-Thr(Ac3GalN3)-OAll 26 (4.0 g, 5.8 mmol) in dry THF (50 mL) is added at 0°C acetic acid (1 mL) and, subsequently, a solution of tri-n-octylphosphine (3.4 mL, 7.4 mmol) in THF (10 mL). After 2 h, the mixture is concentrated in vacuo. To complete the / /-acetylation, the remainder is stirred with acetic anhydride (2 mL)-pyridine (10 mL) for 6 h, concentrated in vacuo. Toluene (3 x 20 mL) is distilled in vacuo from the residue, which is subsequently purified by flash chromatography on silica gel (100 g) in petroleum ether-ethyl acetate —> ethyl acetate. The product is recrystallized from ethyl acetate-petroleum ether yield, 3.9 g (94%) mp 66-68° C [a]D +36.3° (c 1, CHC13) Rf 0.56 (ethyl acetate). 

Petkovic, D.M. Kopecni, M.M. Mltrovic, A.A. Solvent extraction of nitric, hydrochloric and sulfuric acid and their uranyl salts with tri-n-octylphosphine oxide, Solvent Extr. Ion Exch. 10 (1992) 685-696. 

Peng er a/.6 "71 have proposed the use of greener Cd sources such as cadmium oxide, carbonate and acetate instead of the dimethylcadmium. These workers suggest that the size distribution of the nanocrystals is improved by the use of hexadecylamine, a long-chain phosphonic acid or a carboxylic acid. The method can be extended to prepare CdS nanoparticles by the use of tri-n-octylphosphine sulfide (TOP-S) and hexyl or telradecyl phosphonic acid in mixture with TOPO-TOP. Hyeon and coworkers71 have prepared nanocrystals of several metal sulfides such as CdS, ZnS, PbS, and MnS with different shapes and sizes by the thermolysis of metal-oleylamine complexes in the presence of S and oleylamine (Fig. 7). 

Alkyl esters of phosphoric acid and phosphine oxides will extract metais and mineral acids by direct solvation. Tri-n-butyl phosphate (TBP) and tri-w-octylphosphine oxide (TOPO)... 

The mechanism of U02 " extraction by monoalkyl phosphoric acid reagents appears to be a more complex process than for their dialkyl counterparts. This results from the polymerization of the monoalkyl phosphate in the organic phase and the hydration of the extracted uranyl species so that variable stoichiometries arise for the extractant/water/UO complex. The extraction of from sulfuric acid by mono-2,6,8-trimethylnonyl phosphoric acid (H2DDP) and mono-n-butyl phosphoric acid (H2MBP) as 0.05 M solutions in benzene was shown to follow equations (61) and (62) when an excess of extractant was present. When an excess of uranium was present, equations (63) and (64) applied where n, x, y and z were variable numbers which depended upon the extent of extractant polymerization and hydration of the extracted species. Synergistic effects may also be found with the monoalkyl phosphoric acid extractants and in one recent example the use of tri-n-octylphosphine ocxide (TOPO) as a synergist with H2MEHP allowed the extraction of U02 from phosphoric acid solutions. The uranium may be returned to the aqueous phase by contact with concentrated acid, which reverses the extraction process by protonation of the phosphate. 

The Extraction of Uranium (VI) from Sulphuric Acid Solutions by Tri-w-Octylphosphine Oxide... 

We have used tri-n-octylphosphine oxide (TOPO) as a solvent extractant of uranium(VI) and thorium(IV) from nitric and hydrochloric acid solutions (1-3). In contrast, the extraction of uranium(VI) and thorium(IV) from nitric and hydrochloric acid solutions has been investigated by tri-n-butylphosphate (TBP) (4, 5). However, since TBP reveals a poor efficiency for the extraction of metals from sulphuric acid solutions, this paper extends the work to the extraction of uranium(VI) from sulphuric acid solutions by TOPO. 

A similar concept was used for other environmental applications, for example, phenoxy acids, sulfonureas, phenolic compounds, and other environmentally important persistent pollutants [68, 76, 141, 143, 155-166]. Also, in the same manner, several drugs were enriched and determined in body fluids such as urine [144-146, 167-172] or blood [147, 156, 157, 173, 174]. A very advanced apphcation of SLM for analytical purposes, where transport process was based on simple diffusion with pH adjustment of aqueous phase, is the extraction of the basic drug, bambuterol, for pretreatment of plasma samples before analysis with capfflary zone electrophoresis (CZE) [147]. Bambuterol was used as a model substance in a separation system, where either 6-undecanone or a mixture of di- -hexyl ether (DHE) and tri- -octylphosphine oxide (TOPO) was used as membrane phase. It was possible not only to achieve a very low hmit of detection ( 50 nmol/1) but also to ensure the removal of salts from the sample. It helped to obtain the low ionic strength of the blood plasma samples and permitted subsequent sample stacking in the caphlary electrophoresis step. 

Shen, Y., Gronberg, L., Jonsson, J. A. (1994). Experimental studies on the enrichment of carboxylic acids with tri-i -octylphosphine oxide as extractant in a supported liquid membrane. Anal. Chim. Acta, 292, 31-39. 

The reagent has been used successfully for conversion of hydroxy carboxylic acid esters into the corresponding chloro esters.4 Bromo esters are obtained if CBr4 is used. The replacement occurs with inversion. The method is applicable to hindered a-hydroxy esters. Hooz and Gilani5 state that the reaction is more rapid if tri-n-octylphosphine is used in place of triphenylphosphine. 

Forbes and Silver [40] made a systematic comparison of organic phos-phonates, phosphates and phosphinates based on the results of the 60-minute four-ball wear test under a 15 kg load at 1500 rpm. On plotting the wear data for n-butyl di-n-octylphosphinate, di-n-butyl n-hexylphosphonate, di-n-butyl phenylphosphonate, diethyl benzylphos-phonate, diethyl o-nitrophenylphosphonate and tri-n-butyl phosphate against the ionization constants of the corresponding parent acids (expressed as pK ), the solid curve of Fig. 11-10 was obtained. This led them to the hypothesis that the involvement of carbon-phosphorus bonding... 

Liquid-liquid extraction of short-chain organic acids, ketoacids, or dicarboxylic acids result in low and often unreproducible extraction yields due to the hydrophilic character of the analytes. However, some authors report reproducible results for short-chain acids at mg/1 concentrations after liquid-liquid extraction at pH 2, although extraction yields remain low. Note also that organic solvents, namely diethylether, may be contaminated with organic acids. An unusual variation in liquid-liquid extraction is the use of tri-n-octylphosphine oxide (TOPO) in methyl-tert-butylether (MtBE) to enhance extraction yields, e.g., of acrylic acid in marine waters and of organic acids in aqueous solutions obtained from air collection chambers." TOPO s very low solubility in water and its high polarity make it suitable for extraction of polar compounds. The extraction yield for acrylic acid was 40% and its detection limit after derivatization with pentafluorobenzyl bromide was estimated to be 3 nM. ... 

Vairavamurthy, A., Andreae, M. O., and Brooks, J. M., Determination of acrylic acid in aqueous samples by electron capture GC after extraction with tri-n-octylphosphine oxide and derivatisation with pentafiuorobenzyl bromide. Anal. Chem., 58, 2684-2687, 1986. 

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