Tri-n-octylphosphine oxide TOPO

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... 

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. ... 

Neutral extractants may be used for uncharged metal complexes, ionic salts, and strong acids. Examples include ethers such as diethylether and diisopropylether ketones such as methylisobutyl ketone (MIBK or hexone) and neutral organophosphorous compounds such as tri-n-butylphosphate (TBP), tri-n-octylphosphine oxide (TOPO), triphenylphosphate (TPP), and triphenyphosphine oxide (TPPO). Such neutral extractants have long been used for extracting actinides and lanthanides from nitric acid solutions. 

Surfactants are crucial in the colloidal chemical synthesis of nanocrystals. Popularly used surfactants include tri-n-octylphosphine (TOP), tri-n-octylphosphine oxide (TOPO 6, 14), hexadecylamine (17), fatty acids, and phosphonic acids (18-20). In general, the polar head groups of the surfactants bind to the surface of the nanocrystals, as illustrated in Figure 6.10 (21). The surfactants play crucial roles in the nanocrystal synthesis (14-16). First, the surfactant capping prevents the agglomeration of the nanocrystals, endowing them with a good colloidal stability. Nanocrystals have a... 

Supported liquid membranes (SLMs) consisting of 5% tri-n-octylphosphine oxide (TOPO) dissolved in di-w-hexylether/n-undecane (1 1) have been used in the simultaneous extraction of a mixture of three stUbene compounds (dienestrol, diethylstilbestrol, and hexestrol) in cow s milk, urine, bovine kidney, and liver tissue matrices [183]. The efficiencies obtained after the enrichment of 1 ng/1 stilbenes in a variety of biological matrices of milk, urine, liver, kidney, and water were 60-70, 71-86, 69-80, 63-74, and 72-93%, respectively. A new method to contribute to the discrimination of polyphenols including resveratrol with synthetic pores was proposed [184]. The work [185] evaluated two types of commonly available chiral detectors for their possible use in chiral method development and screening polarimeters and CD detectors. Linearity, precision, and the limit of detection (LOD) of six compounds (trans-stilbene oxide, ethyl chrysanthemate, propranolol, 1-methyl-2-tetralone, naproxen, and methyl methionine) on four common detectors (three polarimeters and one CD detector) were experimentally determined and the limit of quantitation calculated from the experimental LOD. trans-Stilbene oxide worked well across all the detectors, showing good linearity, precision, and low detection limits. However, the other five compounds proved to be more discriminating and showed that the CD detector performed better as a detector for chiral screens than the polarimeters. 

TBP, but not necessarily with the same solvation number for all elements. Tri-n-octylphosphine oxide (TOPO) and tri-n-butylphosphine oxide (TBPO) extract Pu(IV) and Pu(VI) as the di-solvate.The data of Martin andOckenden is ven in Figs. 9 and 10 for extraction of several elements into 0.1 M TOPO in cyclohexane from HNOg and... 

Another SPE procedure for preconcentration of uranium in natural waters used octadecyl silica membrane disks modified by tri-n-octylphosphine oxide (TOPO) (Shamsipur et al. 1999). The high extractive properties of organic phosphorus compounds for uranyl ions are well known (e.g., TBP in the nuclear fuel cycle). 

Tri-n-octylphosphine oxide [TOPO] and di(2-ethylhexyhphosphoric acid Environmental [75]... 

The phosphine oxides are powerful extractants. Tri-n-octylphosphine oxide (TOPO) is the most thoroughly investigated of these compounds, but the properties of tributylphosphine oxide (TBPO) are also fairly well-known [103, 176]. The values of log for the extraction with carbon tetrachloride ... 

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