TOPO tri-n-octylphosphine

TOP tri-n-octylphosphine TOPO tri-n-octylphosphine oxide HDA hexadecylamine ODE octadecene... 

Uses Solvent antifoam plasticizer Trioctylphosphine oxide CAS 78-50-2 EINECS/ELINCS 201-121-3 Synonyms 1 -(Dioctyl-phosphinoyl)-octane TOPO Tri-n-octylphosphine oxide Tri-n-octylphosphinic oxide... 

Aliquat-336, tricaprylyl-methylammonium chloride. TOPO, tri-n-octylphosphine oxide. 

DPA 2,6-pyridinedicarboxylic acid TTA thenoyltrilluoroacetone TOPO tri-n-octylphosphine oxide. 

Fig. 4. Lewis bases that form adducts with rare-earth tris / -diketonates. Abbreviations bipy = 2,2 -bipyridine phen = 1,10-phenanthroline terpy = 2,2, 6, 2"-terpyridyl bath = bathophenanthroline or 4,7-diphenyl-l,10-phe-nanthroline Hpbm = 2-(2-pyridyl)benziraidazole tppo = triphenylphosphine oxide tbpo = tri-n-butylphosphine oxide topo = tri-n-octylphosphine oxide tbp = tributylphosphate dmso = dimethylsulfoxide.

Highly monodisperse CdSe/CdS core/shell nanoparticles have been prepared by thermolysis in tri-n-octylphosphine oxide (TOPO) using [Cd(Se2CNMe( Hex))2] (250 °C for 30 min) and [Cd(S2CNMe( Hex))2] (250 °C for 30 min) as single-molecule precursors in a one-pot synthesis [118,119]. [Cd(Se2CNMe(Hex))2] (0.8 g) was dissolved in trioctylphos-... 

Tri-n-octylphosphine oxide (TOPO) has been the most popular phosphine oxide to be used as an extractant for the determination of iron, uranium, plutonium, molybdenum, titanium and thorium among other metals.43 44... 

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). 

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 routine synthesis of well-defined semiconductor nanocrystallites was really opened up in a landmark paper by Murray, Norris and Bawendi [34]. They reacted solutions of dimethylcadmium (CH3)2Cd (in tri-n-occtylphosphine TOP) and tri-n-octylphosphine selenide (TOPSe) in hot tri-n-octylphosphine oxide (TOPO) in... 

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. 

Another group of ion-association systems is represented by solvated salts (usually nitrates, but also halides and sulphates). Solutions (1-50%) of tri-n-butyl phosphate (TBP, formula 1.11) in hexane, CCI4, and solutions (1-20 %) of tri-n-octylphosphine oxide (TOPO, formula 1.12) in cyclohexane are most often used as the extractants. Solvation with TBP or TOPO (through the strongly basic oxygen atom of the phosphoryl group) enables metal salts. 

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

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. ... 

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