Naphthalene solubilization

Mukeijee, P., Cardinal, J.R. Benzene derivatives and naphthalene solubilized in micelles polarity of microenvironments, location and distribution in micelles, and correlation with surface activity in hydrocarbon-water systems. J. Phys. Chem. 1978, 82(14), 1620-1627. 

Beckman, Brennecke, and their research groups were the first to realize that the combination of SCCO2 and an ionic liquid can offer special advantages. They observed that, although SCCO2 is surprisingly soluble in some ionic liquids, the reverse is not the case, with no detectable ionic liquid solubilization in the CO2 phase. On the basis of these results they described a method to remove naphthalene quantitatively from the ionic liquid [BMIM][PFg] by extraction with SCCO2 [5]. Sub-... 

Betzemeier et al. (1998) have used f-BuOOH, in the presence of a Pd(II) catalyst bearing perfluorinated ligands using a biphasic system of benzene and bromo perfluoro octane to convert a variety of olefins, such as styrene, p-substituted styrenes, vinyl naphthalene, 1-decene etc. to the corresponding ketone via a Wacker type process. Xia and Fell (1997) have used the Li salt of triphenylphosphine monosulphonic acid, which can be solubilized with methanol. A hydroformylation reaction is conducted and catalyst recovery is facilitated by removal of methanol when filtration or extraction with water can be practised. The aqueous solution can be evaporated and the solid salt can be dissolved in methanol and recycled. 

The aqueous cores of reverse micelles are of particular interest because of their analogy with the water pockets in bioaggregates and the active sites of enzymes. Moreover, enzymes solubilized in reverse micelles can exhibit an enhanced catalytic efficiency. Figure B4.3.1 shows a reverse micelle of bis(2-ethylhexyl)sulfosuccinate (AOT) in heptane with three naphthalenic fluorescent probes whose excited-state pK values are much lower than the ground-state pK (see Table 4.4) 2-naphthol (NOH), sodium 2-naphthol sulfonate (NSOH), potassium 2-naphthol-6,8-disulfonate (NSOH). The spectra and the rate constants for deprotonation and back-recombination (determined by time-resolved experiments) provide information on the location of the probes and the corresponding ability of their microenvironment to accept a proton , (i) NDSOH is located around the center of the water pool, and at water contents w = [H20]/[A0T] >... 

A combined effect of natural organic matter and surfactants on the apparent solubility of polycyclic aromatic hydrocarbons (PAHs) is reported in the paper of Cho et al. (2002). Kinetic studies were conducted to compare solubilization of hydro-phobic contaminants such as naphthalene, phenanthrene, and pyrene into distilled water and aqueous solutions containing natural organic matter (NOM) and sodium dodecyl sulfate (SDS) surfactant. The results obtained after 72hr equilibration are reproduced in Fig. 8.19. The apparent solubility of the three contaminants was higher in SDS and NOM solutions than the solubility of these compounds in distilled water. When a combined SDS-NOM aqueous solution was used, the apparent solubility of naphthalene, phenanthrene, and pyrene was lower than in the NOM-aqueous solution. 

Li A, Andren AW, Yalkowsky SH (1996) Choosing a cosolvent Solubilization of naphthalene and cosolvent properties. Environ Toxicol Chem 15 2233-2239 Lin ZQ, Schemenauer RS, Cervinka V, Zayed A, Lee A, Terry N (2000) Selenium volatilization from a sod-plant system for the remediation of contaminated water and soil in the San Joaquin Valley. J Environ Quality 29 1048-1056 Lindsay WL (1979) Chemical equilibria in soils. Wiley, New York... 

Below CMC the amount dissolved remains constant, which corresponds to its solubility in pure water. The slope of the plot above CMC corresponds to 14 mole SDS 1 mol naphthalene. It is seen that, at the CMC, the solubility of naphthalene abruptly increases. This is because all micelles can solubilize water-insoluble organic compounds. A more useful analysis can be carried out by considering the thermodynamics of this solubilization process. 

It may be expected that other, highly structured solvents with a tri-dimensional network of strong hydrogen bonds, would also permit micelle formation by surfactants, but little evidence of such occurrences has been reported. On the other hand, surfactants in non-polar solvents, aliphatic or aromatic hydrocarbons and halocarbons tend to form so-called inverted micelles, but these aggregate in a stepwise manner rather than all at once to a definite average size. In these inverted micelles, formed, e.g., by long-chain alkylammonium salts or dinonyl-naphthalene sulfonates, the hydrophilic heads are oriented towards the interior, the alkyl chains, tails, towards the exterior of the micelles (Shinoda 1978). Water and hydrophilic solutes may be solubilized in these inverted micelles in nonpolar solvents, such as hydrocarbons. 

By comparing with corresponding spectra of ion pairs in different solvents one obtains information on the local environment at the micellar surface73. (The polarity was expressed in terms of a so-called effective dielectric constant). Amphiphiles with a benzene ring also show an UV absorption74-76. UV spectra of solubilized species like benzene, naphthalene and pyrene have been extensively studied and compared with spectra of the compound in reference solvents to provide an estimate of the polarity in the vicinity of the solubilizate. 

The difference is ascribed to the smaller micelle cavity of succinimides relative to sulfonates. Mixed micelles of naphthalene-sulfonate-succinimide show weaker solubilization capacity than that of individual additives. The solubilization of water in a micellar system is closely related to the micelle core (Fontana, 1968). Addition of water to this non-polar solution, as engine lubricating oil is, produces a new set of phenomena. For small amounts of water, the micellar aggregates show swelling by uptake of water. The highly bounded water in reversed micelles makes surfactants less effective. 

Hexapus in water solubilizes cholesterol, phenol blue (Kassoc = 1.0 x 104 M 1), naphthalene, and hydrophobic esters. Thus, hexapus seems non-selective in its binding characteristics (just like micelles). Universal binding has the advantage that almost any water-insoluble compound can be collected by the host molecule without regard to subtle structural variations. On the other hand, potential catalysts based on hexapus and other multi-armed systems would not be expected to manifest high specificity. Flexible chains do not lend themselves to a precise fit. 

The photodechlorination of 2,2/,3,3/,6,6/-hexachlorobiphenyl and of three commercial mixtures of polychlorinated biphenyls solubilized in an aqueous solution of poly(sodium styrenesulphonate-co-2-vinylnaphthalene) was studied with the use of solar-simulated radiation426,427. The reaction was found to be photosensitized by the naphthalene antenna units present in the copolymer. Exciplex formation and generation of radical anions lead to dechlorination. 

A second approach has been developed, in part because of difficulties encountered in disposing of scintillation fluids containing naphthalene, which is insoluble in water. In this approach, solubilizer or detergents are added to the standard toluene-based scintillation cocktails. Hyamine hydroxide, NCS, Soluene-100,... 

Because the micellar interior is far from being rigid, a solubilized substrate is relatively mobile. Like micelle formation, solubilization is a dynamic equilibrium process. Representative recent examples are the solubilization of benzene, naphthalene, anthracene, and pyrene in aqueous solution by the addition of 1-dodecanesulfonic acid [391], the solubilization of fullerene Ceo in aqueous solutions of the non-ionic surfactant Triton X-100 [392], and the solubilization of a cholesteryl-group bearing pullulane (a hydrophobized polysaccharide) [393]. 

Thus, there appears to be something unique about the weakly acidic phenolic materials. In addition to phenol itself, 3,5-xylenol, 2-naphthol, phenol-naphthalene (1 1). and cresylic acid all show ability to solubilize the coal. Recently, Darlage and Bailey have studied the phenol catalyzed depolymerization of a Kentucky coal (Pond Creek Seam, Pike County). (16) This coal does not depolymerize efficiently and would compare with the poorest coals tested with data shown in Table II. These authors also show that phenolic solvents in general cause solvation of coal whereas non-phenolic aromatics add to coal but do not solubilize the coal. 

Information concerning solubilization of hydrocarbons in ionic surfactant micelles was obtained from 2H NMR relaxation and H NMR paramagnetic relaxation measurements. The location of the hydrocarbons (benzene naphthalene, triphenylene cyclohexane, cyclododecane and tert-butylcyclohexane) in micelles... 

Micellar Exit Rates. In micellar solubilization, the dominant factors governing the exit and reentry rates of solubilizates are largely unknown. The exit rates for naphthalene, biphenyl, and 1-methylnaphthalene from ionic micelles are >5 X 104 s exit rates for anthracene and pyrene are reported as... 

For comparison with the alternating copolymer we synthesized a randcm polymer of 2-VN and MA containing ca. 10 mol of 2-VN (higher naphthyl contents did not dissolve In basic H O). Solubilization by this copolymer demonstrates 1) a much lower sensitization efficiency than the alternating copolymer, 2) no spectral shift between directly excited and sensitized AnOH, and 3) In the absense of AnOH a clearly discernible exclmer component In the fluorescence (see Fig. 7). While comparison of the alternating and random copolymer Is dangerous because of the different naphthyl contents, these results do Imply that 1) the AnOH Is not preferentially associated with the naphthyl moieties In the random copolymer, and 2) the red-shift observed In the sensitized AnOH fluorescence for P(2VN-alt-MA) is the result of naphthalene - anthryl Interactions. 

Based on the x values solubilized Anth or AnOH is apparently not as Intimately associated with the naphthalene groups as covalently bound anthracene. 

The naphthalene monomer fluorescence lifetime is shortened by the solubilized Anth to an extent in reasonable agreement with the observed v values. Following the general analysis of Fredrickson and Frank , we have argued that x can be estimated from the fluorescence decay from the expression... 

The photolytic removal of chlorine from chlorobenzene, chlorophenols and chlorinated biphenyls and dioxins continues to be examined as a potential solution to the problem of the destruction of these compounds when present as environmental pollutants. Guillet has reported that aqueous solutions of the copolymer of vinyl-naphthalene and styrene sulphonate will solubilize to a small degree 2,2, 3,3, 6,6 -hexachlorobiphenyl, and that illumination of the solution with simulated sunlight leads to the formation of biphenyls with fewer chlorine substituents. It is suggested that the process involves the absorption of light by the naphthalene and exciplex formation with the biphenyl followed by electron transfer to the biphenyl. The chlorinated biphenyl anion radical would then be expected to expel chloride ion. The dechlorination of mixtures of variously chlorinated biphenyls (such as those typically used as... 

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