Dodecane solvent

Fig. 6. Reaction rate coefficients for the combination of f-butyl radicals in Aj n-hexa-decane solvent V, n-dodecane solvent , n-decane solvent X, n-octane solvent 8 n-heptane solvent and of allyl radicals in propane ( ) and melhylallyl radicals in isobutane (O) plotted against the Smoluchowski—Stokes—Einstein rate coefficient, eqn. (30). The broken line is of unit slope. The solid line is a comparison of the steady-state (t-> >) Collins and Kimball rate coefficient [eqn. (26)] with the activation rate coefficient, feact = 1011 dm3 mol-1 s 1 and the diffusion-limited rate coefficient 4irRD replaced by eqn. (30). After Schuh and Fischer [40].

Moyer, B.A., Baes Jr. C.F., Case, F.I., Driver, J.L. 2001. Liquid-liquid equilibrium analysis in perspective II. Complete model of water, nitric acid, and uranyl nitrate extraction by di-2-ethylhexyl sulfoxide in dodecane. Solvent Extr. Ion Exch. 19 (5) 757-790. 

Tachimori, S., Sasaki, Y., Suzuki, S. 2002. Modification of TODG A-n-dodecane solvent with a monoamide for high loading of lanthanides(III) and actinides(III). Solvent Extr. Ion Exch. 20 (6) 687-699. 

Apichaibukol, A., Sasaki, Y., Morita, Y. 2004. Effect of DTPA on the extraction of actinides(III) and lanthanides(III) from nitrate solution into TODGA/ra-dodecane. Solvent Extr. IonExeh. 22 (6) 997-1011. 

S. Nave, G. Modolo, C. Madic, and F. Testard. Aggregation properties of n,n,n, n -tetraoctyl-3-oxapentanediamide (TODGA) in n-dodecane. Solvent Extr. Ion Exch., 22 1-25, 2004. 

Kinetic studies A kinetic study of PA transformation was carried out in a batch reactor at 433 K in the presence of sulfolane (very polar) or dodecane (nonpolar) as solvent.[48] The initial reaction rates, the decrease in rate with time and the product distribution depend very much on the solvent polarity. The initial rates are lower in the polar sulfolane than in the nonpolar dodecane solvent. In the latter solvent, but not in sulfolane, there is a rapid decrease in the reaction rates, this decrease affecting preferentially the bimolecular formation of p-AXAP and p-HAP. As a consequence, these products are much more favoured with respect to o-HAP in sulfolane than in dodecane. The (p-AXAP + p-HAP)/o-HAP ratio is equal to 7 with sulfolane and 1 with dodecane. 

As will be shown, the equation rates obtained for o-HAP formation in the case of strong (polar sulfolane) and weak (nonpolar dodecane) solvent adsorption (Figure 2.3) explain the inhibiting effect of sulfolane as well as the differences in reaction order with respect to PA in the polar (order 1) and nonpolar (order 0.5)... 

An initial experiment involving the treatment of small irradiated Pu/Al targets for the production of americium 243 and curium 244 was carried out in France in 1968 (2). The chemical process was based essentially on the use of a system comparable to the Talspeak system. After plutonium extraction by a 0.08 M trilaurylammonium nitrate solution in dodecane containing 3 vol % 2-octanol, the actinides (americium, curium) were coextracted with a fraction of the lanthanides by a 0.25 M HDEHP -dodecane solvent from an aqueous solution previously neutralized by A1(N0 ) x(0H)x and adjusted to 0.04 M DTPA. The actinides were selectively stripped by placing the organic phase in contact with an aqueous solution of the composition 3 M LiN0 -0.05 M DTPA. While this experiment achieved the recovery of 150 mg of americium 243 and 15 mg of curium 244 with good yields, the process presented a drawback due to the slow extraction of Al(III) which saturates the HDEHP. This process was therefore abandoned. 

Very efficient enantioseparation of racemic DNB-leucine 23 exploiting an extraction with a mechanistically designed quinine 1-adamantylcarbamate 24 bearing a highly hydrophobic side arm has been reported by Lindner and coworkers. The most efficient extraction was achieved with aqueous ammonium acetate buffer/dodecane solvent system. After back-extraction of the organic phase with 1 M H3PO4 solution, the preferentially complexed S-enantiomer of 23... 

Mice chronically administered a 10% pyrene solution throughout their lifetimes did not develop skin tumors (Wynder and Hoffmann 1959a). However, prolonged dermal exposure of mice to 0.5% pyrene in decalin/n-dodecane solvent produced a slightly elevated (15%) skin carcinoma incidence the level of statistical significance was not provided (Horton and Christian 1974). 

Figure 1 Transformation of the phenol-phenyl acetate mixture over 500 mg of H-BEA-10. Yield in HAP (%) as a function of time (h) in sulfolane and in dodecane solvents...

Union Carbide Corp. tetraethyl-ene glycol (TETRA) the solvent is free of water a dodecane re-flux is used which is later recovered by distillation 100 reciprocating-plate extractor the extract leaving the primary ex-tractor is essen-tially free of feed ahphatics, and no further purification is necessary two-stage extraction uses dodecane as a displacement sol-vent in the second stage... 

An improved solvent extraction process, PUREX, utilizes an organic mixture of tributyl phosphate solvent dissolved in a hydrocarbon diluent, typically dodecane. This was used at Savannah River, Georgia, ca 1955 and Hanford, Washington, ca 1956. Waste volumes were reduced by using recoverable nitric acid as the salting agent. A hybrid REDOX/PUREX process was developed in Idaho Falls, Idaho, ca 1956 to reprocess high bum-up, fuUy enriched (97% u) uranium fuel from naval reactors. Other separations processes have been developed. The desirable features are compared in Table 1. 

Chemistry. Chemical separation is achieved by countercurrent Hquid— Hquid extraction and involves the mass transfer of solutes between an aqueous phase and an immiscible organic phase. In the PUREX process, the organic phase is typically a mixture of 30% by volume tri- -butyl phosphate (solvent) and a normal paraffin hydrocarbon (diluent). The latter is typically dodecane or a high grade kerosene (20). A number of other solvent or diluent systems have been investigated, but none has proved to be a substantial improvement (21). 

Figure 1.13 Temperature dependence of A U /Alc values for /-butyl radicals with dodecane (—) or 3-methyl-3-pentanol (---------------) as solvent.

An example for a partially known ternary phase diagram is the sodium octane 1 -sulfonate/ 1-decanol/water system [61]. Figure 34 shows the isotropic areas L, and L2 for the water-rich surfactant phase with solubilized alcohol and for the solvent-rich surfactant phase with solubilized water, respectively. Furthermore, the lamellar neat phase D and the anisotropic hexagonal middle phase E are indicated (for systematics, cf. Ref. 62). For the quaternary sodium octane 1-sulfonate (A)/l-butanol (B)/n-tetradecane (0)/water (W) system, the tricritical point which characterizes the transition of three coexisting phases into one liquid phase is at 40.1°C A, 0.042 (mass parts) B, 0.958 (A + B = 56 wt %) O, 0.54 W, 0.46 [63]. For both the binary phase equilibrium dodecane... 

Initiator 1 (fasti solvent A solvent B Temp.°C (benzene) (n-decane) solvent C (dodecane) model fit Yl = 0.6346... 

These are oxidised by both Fe(III) and Cu(II) octanoates (denoted Oct) in nonpolar solvents at moderate temperatures . 80-90 % yields of the corresponding disulphide are obtained with Fe(III) and this oxidant was selected for kinetic study, the pattern of products with Cu(II) being more complex. The radical nature of the reaction was confirmed by trapping of the thiyi radicals with added olefins. Simple second-order kinetics were observed, for example, with l-dodecane thiol oxidation by Fe(Oct)3 in xylene at 55 °C (fcj = 0.24 l.mole . sec ). Reaction proceeds much more rapidly in more polar solvents such as dimethylformamide. The course of the oxidation is almost certainly... 

The cracking of diphenylmethane (DPM) was carried out in a continuous-flow tubular reactor. The liquid feed contained 29.5 wt.% of DPM (Fluka, >99%), 70% of n-dodecane (Aldrich, >99% solvent) and 0.5% of benzothiophene (Aldrich, 95% source of H2S, to keep the catalyst sulfided during the reaction). The temperature was 673 K and the total pressure 50 bar. The liquid feed flow rate was 16.5 ml.h and the H2 flow rate 24 l.h (STP). The catalytic bed consisted of 1.0 g of catalyst diluted with enough carborundum (Prolabo, 0.34 mm) to reach a final volume of 4 cm. The effluent of the reactor was condensed at high pressure. Liquid samples were taken at regular intervals and analyzed by gas chromatography, using an Intersmat IGC 120 FL, equipped with a flame ionization detector and a capillary column (Alltech CP-Sil-SCB). 

Stopped flow mixing of organic and aqueous phases is an excellent way to produce dispersion within a few milliseconds. The specific interfacial area of the dispersion can become as high as 700 cm and the interfacial reaction in the dispersed system can be measured by a photodiode array spectrophotometer. A drawback of this method is the limitation of a measurable time, although it depends on the viscosity. After 200 ms, the dispersion system starts to separate, even in a rather viscous solvent like a dodecane. Therefore, rather fast interfacial reactions such as diffusion-rate-limiting reactions are preferable systems to be measured. 

Using the spectroscopic technique previously described, Didenko et al., investigated the collapse temperature for rare gases in organic solvents (octanol and dodecane) with Cr(CO)6 as the spectroscopic probe [58]. They observed a trend in temperature consistent with that predicted based on differences in thermal... 

As reported by Griengl and coworkers, benzaldehyde, decanal, undecanal, and dodecanal were reacted with HCN in a two-phase solvent system aqueous buffer and ionic liquids 1 -ethyl-3-methylimidazolium tetrafluoroborate, 1 -methyl-3-propylimidazolium tetrafluoroborate, and l-butyl-3-methyl-imidazolium tetrafluoroborate in the presence of the HNLs from Prunus amygdalus and Hevea brasiliensis. When compared with the use of organic solvents as the nonaqueous phase, the reaction rate was significantly increased and the enantioselectivity remained good [51]. 

The systems discussed up to now all showed chiral susceptibilities that were of the same order of magnitude or smaller than the achiral susceptibility components. The system that we discuss in this section has chiral susceptibilities that dominate the nonlinear optical response.53 The material is a chiral helicenebisquinone derivative shown in Figure 9.22. In bulk samples, the nonracemic, but not the racemic, form of the material spontaneously organizes into long fibers clearly visible under an optical microscope. These fibers comprise columnar stacks of helicene molecules.54,55 Similar columnar stacks self-assemble in appropriate solvents, such as n-dodecane, when the concentration exceeds 1 mM. This association can be observed by a large increase in the circular dichroism (CD) of the solutions. 

Figure 2.13 Influence of emulsion solvent on particle morphology (a) hexane, (b) octane, (c) dodecane and (d) cyclohexane. Surfactant is Span 80. All scale bars are 100 pm. (Reproduced from ref. 8, with permission.)... 

Oxygenated (e.g. alcohols, ethers, ketones and esters) Aliphatic hydrocarbons (e.g. cyclohexane, dodecane) Aromatic hydrocarbons (e.g. xylene, mesitylene) Dipolar aprotic (e.g. DMSO, DMF, NMP) Chlorinated solvents (e.g. dichloromethane)... 

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