Anthracene aqueous solubility

Reported aqueous solubilities of anthracene at various temperatures and the reported empirical... 

Dohanyosova, P., Dohnal, V., Fenclova, D. (2003) Temperature dependence of aqueous solubility of anthracenes accurate determination by a new generator column apparatus. Fluid Phase Equil. 214, 151-167. 

As shown in the example below, a similar approach can be used if a suitable value for the aqueous solubility of anthracene is available. Again, Table 8.2 gives both class specific and more general equations for estimating Koc from S. 

Figure 9.4 Physicochemical properties of anthracene and phenanthrene according to the PHYSPROP database [14]. The large discrepancy in MP of both these compounds, AMP = 115°C, explains their differences in aqueous solubility and vapor pressures. The difference in solubility of molecules calculated using GSE (equation 9.3) Alog.S = 0.01 115 = 1.15 approximately corresponds to the experimentally observed value AlogN = 1.42.

The octanol-water partition coefficient — and hence the bioconcentration potential — has also been correlated with the aqueous solubility, although the experimental determination of the latter for poorly water soluble compounds also presents some problems. A dialysis procedure that is applicable to a wide range of water solubilities ranging from cyclohexanol (37.5 g/1) to anthracene (0.0488 mg/1) has been developed (Etzweiler et al. 1995). The following relations have been proposed (Mackay 1982) ... 

Aqueous Solubilities at 25°C. Table IX compares the solubilities determined by DCCLC with some values reported by other investigators. Of the 12 values reported, there are only two cases of gross disagreement with the consensus literature value. Those are the values for anthracene and triphenylene. 

Correlations of Solubility with Molecular Parameters. The aqueous solubility of aromatic hydrocarbons has been shown by Klevens (25) to be related to carbon number, molar volume, and molecular length. These parameters along with the molar solubilities (expressed as — In S) of the compounds studied are presented in Table XIII. Figures 5 through 7 demonstrate the relationship between each of these parameters and solubility. These figures show that there are several compounds whose anomalous behavior makes accurate extrapolations of solubility from these relationships impossible. For example, anthracene and phenanthrene are structural isomers. They, therefore, have identical carbon numbers and very similar molar volumes. However, their aqueous solubilities differ by more than a factor of 20. Phenanthrene, fluoranthene, pyrene, and triphenylene all have very similar molecular lengths but their respective aqueous molar solubilities at 25°C are 5.6 X 10 6, 1.0 X 10"6, 6.8 X 10"7, and 2.8 X 10 8. 

Figure B-4. Temperature dependence of the aqueous solubility of anthracene...

Fig. 2. Contribution of the aromatic rings of two polycylic aromatic hydrocarbons (PAHs) to the quantum-connectivity index CRg(p) (left) and to aqueous solubility expressed as InC ) (right). The compound at the top is benzo[a]pyrene and the one at the bottom is benz[a]anthracene.

Breslow studied the dimerisation of cyclopentadiene and the reaction between substituted maleimides and 9-(hydroxymethyl)anthracene in alcohol-water mixtures. He successfully correlated the rate constant with the solubility of the starting materials for each Diels-Alder reaction. From these relations he estimated the change in solvent accessible surface between initial state and activated complex " . Again, Breslow completely neglects hydrogen bonding interactions, but since he only studied alcohol-water mixtures, the enforced hydrophobic interactions will dominate the behaviour. Recently, also Diels-Alder reactions in dilute salt solutions in aqueous ethanol have been studied and minor rate increases have been observed Lubineau has demonstrated that addition of sugars can induce an extra acceleration of the aqueous Diels-Alder reaction . Also the effect of surfactants on Diels-Alder reactions has been studied. This topic will be extensively reviewed in Chapter 4. 

The theory and development of a solvent-extraction scheme for polynuclear aromatic hydrocarbons (PAHs) is described. The use of y-cyclodextrin (CDx) as an aqueous phase modifier makes this scheme unique since it allows for the extraction of PAHs from ether to the aqueous phase. Generally, the extraction of PAHS into water is not feasible due to the low solubility of these compounds in aqueous media. Water-soluble cyclodextrins, which act as hosts in the formation of inclusion complexes, promote this type of extraction by partitioning PAHs into the aqueous phase through the formation of complexes. The stereoselective nature of CDx inclusion-complex formation enhances the separation of different sized PAH molecules present in a mixture. For example, perylene is extracted into the aqueous phase from an organic phase anthracene-perylene mixture in the presence of CDx modifier. Extraction results for a variety of PAHs are presented, and the potential of this method for separation of more complex mixtures is discussed. 

Source Concentrations in 8 diesel fuels ranged from 0.026 to 40 mg/L with a mean value of 6.275 mg/L (Westerholm and Li, 1994). Lee et al. (1992) reported concentration ranges of 100-300 mg/L and 0.04-2 pg/L in diesel fuel and corresponding aqueous phase (distilled water), respectively. Schauer et al. (1999) reported anthracene in diesel fuel at a concentration of 5 pg/g and in a diesel-powered medium-duty truck exhaust at an emission rate of 12.5 pg/km. Anthracene was detected in a distilled water-soluble fraction of used motor oil at concentrations ranging from 1.1 to 1.3 pg/L (Chen et al., 1994). 

Thomas and Delfino (1991) equilibrated contaminant-free groundwater collected from Cainesville, FL with individual fractions of three individual petroleum products at 24-25 °C for 24 h. The aqueous phase was analyzed for organic compounds via U.S. EPA approved test method 625. Average anthracene concentrations reported in water-soluble fractions of kerosene and diesel fuel were 12 and 25 pg/L, respectively. Anthracene was ND in the water-soluble fraction of unleaded gasoline. 

More extensive studies using somewhat higher wavelengths have been reported by Geacintov et al. (111, 112). These authors used phototendering dyestuffs notably the sodium salt of anthracene 2,7 disulfonic acid as the sensitizer in aqueous solution. For grafting to cellulose acetate and ethyl cellulose 2-methyl anthraquinone which is soluble in organic solvents was used. The mechanism proposed was the removal of a... 

Firstly, it is well known that micellar aggregates in water can solubilize and bind hydrophobic solute molecules that are typically insoluble or only sparingly soluble in bulk water. For example, although the solubility of pyrene and anthracene in water is in the 0.1-0.6 micromolar range, their solubility can easily be increased to the 10 millimolar range in the presence of micelles. The amount of solute solubilized and bound to the micellar aggregate in an aqueous solution is typically proportional to the surfactant concentration up to the limiting value. 

Noncovalent functional strategies to modify the outer surface of CNTs in order to preserve the sp2 network of carbon nanotubes are attractive and represent an effective alternative for sidewall functionalization. Some molecules, including small gas molecules [195], anthracene derivatives [196-198] and polymer molecules [118, 199], have been found liable to absorb to or wrap around CNTs. Nanotubes can be transferred to the aqueous phase through noncovalent functionalization of surface-active molecules such as SDS or benzylalkonium chloride for purification [200-202]. With the surfactant Triton X-100 [203], the surfaces of the CNTs were changed from hydrophobic to hydrophilic, thus allowing the hydrophilic surface of the conjugate to interact with the hydrophilic surface of biliverdin reductase to create a water-soluble complex of the immobilized enzyme [203]. 

The application of UNIFAC to the solid-liquid equilibrium of sohds, such as naphthalene and anthracene, in nonaqueous mixed solvents provided quite accurate results [11]. Unfortunately, the accuracy of UNIFAC regarding the solubility of solids in aqueous solutions is low [7-9]. Large deviations from the experimental activity coefficients at infinite dilution and the experimental octanol/water partition coefficients have been reported [8,9] when the classical old version of UNIFAC interaction parameters [4] was used. To improve the prediction of the activity coefficients at infinite dilution and of the octanol/water partition coefficients of environmentally significant substances, special ad hoc sets of parameters were introduced [7-9]. The reason is that the UNIFAC parameters were determined mostly using the equihbrium properties of mixtures composed of low molecular weight molecules. Also, the UNIFAC method cannot be applied to the phase equilibrium in systems containing... 

Much less data is available for the solubilities of HOP in multicomponent aqueous solvents. The literature provides the solubilities of naphthalene and anthracene in ternary, quaternary and quinary aqueous mixed solvents. Detailed information about the experimental data used in our calculations is listed in Table 2. So far there is no method for testing the self-consistency of the experimental data regarding the solubility of a poorly soluble solid in mixed solvents and the accuracy of the data in Table 2 could not be verified. 

For our computational scheme, it is important to have the solubilities of naphthalene and anthracene in binary aqueous mixed solvents, which are subsystems of the ternary, quaternary and quinary aqueous mixed solvents listed in Table 2 and they are available (8, 9). One can therefore compare the predictions from the solubilities in the individual constituents of the solvent to those obtained on the basis of the solubilities in binary mixed solvents. 

Ternary Mixed Solvent. The solubilities of naphthalene and anthracene in the ternary aqueous mixed solvents (see Table 2) were calculated using Equation 23. The prediction... 

TABLE 5. Comparison between the Experimental Solubilities of Naphthalene and Anthracene in Multicomponent (Ternary, Quaternary and Quinary) Aqueous Mixed Solvents and the Solubilities Predicted with Equation 23... 

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