Solubility 1-chloronaphthalene

In contrast to 1, the related pure host 7 may be obtained in crystalline form 68). The crystal structure of 7 is built via helical chains of alternating intra- and inter-molecular H-bonding through the carboxyl functions. This structure supplies the information that the carboxyl groups are therefore already positioned in an appropriate way to facilitate analogous H-bonding in the known inclusions of 7. As discussed later (Sect. 4.2.2), these are exclusively salt-type associates and as such, intimately interact with the carboxyl groups. Hence one may infer that displacement of the carboxyl functions from position 2 in 1 to position 8 in 7 reduces the ability of inclusion formation. Similar reasons such as the solid-solubility differences observed in the classical naphthalene/chloronaphthalene systems (alpha- vs. beta-substituted derivatives, cf. Ref. 28 may also be applied here. 

There are many dyes which fulfill the above requirements, few of which have been used until now. The first dyes used with a ruby laser were phthalocyanines the free base as well as chloro-aluminum- and vanadium-phthalocyanine in 1-chloronaphthalene or nitrobenzene 22>. While these dyes show little residual absorption 14> and good photochemical stability, the solubility is relatively low and the solvents are not well suited to operation in a laser resonator. 

The formation of a,a -dihalo- >-xylenes as intermediates in the polymerization has been demonstrated, when the electrolysis was conducted at low temperature, as —10° C, and at —0.70 V of the cathode potential in a solution of tetrahydrofuran using a lead or mercury cathode. The polymerization of xylylenes took place immediately above room temperature. Only poly-2-chloro-/>-xylylene prepared from a,a -debromo-2-chloro -xylene and a,a -2-trichloro-/>-xylene were soluble of six polymers of xylene derivatives, and the reduced viscosity of an 0.2 percent solution in chloronaphthalene at 170° C was 0.68 to 0.78. This compared with a reduced viscosity of 0.65 of the same polymer prepared by the reaction of a,a -2-dichloro-/>-xylene with potassium butoxide. 

Poly(chloro-p-xylylenes) containing (in theory) about 5, 10, and 20% butyl-p-xylylene were prepared in this way (see illustration on p. 650). The crystalline melting points of the products (XVII) were in the range 220°-250°C. compared with 290°C. for pure poly (chloro-p-xylylene). Solubility characteristics of the products and a sample of poly (chloro-p-xylylene) were studied by heating in a-chloronaphthalene. The solution temperature is the minimum temperature required to dissolve the product with slow heating. The gel temperature is that at which the solution of the product in a-chloronaphthalene sets to a gel on gradual cooling. Results were as follows ... 

Phthalocyaninato(2-)] iron(II) is a dark blue, thermally stable solid that can be sublimed in vacuo at 300°. It is very soluble in pyridine, giving deep blue solutions of the bis(pyridine) adducts. It also forms an unstable purple hexaaniline adduct when dissolved in aniline. It is soluble in concentrated sulfuric add and dimethyl sulfoxide (slightly) but is insoluble in most other organic solvents. The iron(II) complex, unlike the corresponding iron(II) porphines, is relatively stable toward oxidation to the iron (III) state. The electronic spectrum shows the following absorption bands (1-chloronaphthalene solution) 595 (e = 16,000), 630 (e = 17,000), 658 (e = 63,000) (pyridine solution) 333 (e = 45,000), 415 (e = 15,000), 395 (e = 2000), 658 nm (e = 8000). 

Vacuum treatment df the dihydroxides (63) (66) (R = OH) at 573-730K led to the polyoxides (67) (Eq. 26) The water elimination is detected by thermal analy-sigi08-iu) heatir the less soluble monomers in a heterogenous phase of high boUing solvents like 1-chloronaphthalene or quinoline is successful. With Si(OH)2Pc (65) the corresponding polymer [Si(0)Pc]n (67) was prepared by heating in nitrobenzene with ZnCla Solvent and temperature must be considered, otherwise decomposition may occur. 

For the analysis of VOCs, the most common column is a 75 m X 0.53 mm i.d. DB-624 fused silica capillary with 3 pm film thickness. A typical DB-624 permits detection from vinyl chloride (bp= 13.9°C and solubility = 2700 g/L) up to 2-chloronaphthalene (bp = 256°C), being therefore suitable to determine a wide range of compounds of different volatilities and polarities. For specific applications, e.g., control of trihalomethanes in drinking water, a short column of 30 m can be used, and the analysis time is, of course, reduced. 

Fluorophthalonitrile (0.5 g, 3.4 mmol) and dry zinc(II) acetate (0.17 g, 0.94 mmol) in 1-chloronaphthalene (10 mL) were heated under reflux for 20 h. The cold reaction mixture was diluted with methanol (40 mL) and stirred for 1 h. The blue coloured product was isolated, washed at first with methanol and then with DMF followed by precipitation of the partially soluble phthalocya-nine by addition of methanol. Following filtration the product was again washed with methanol and dried at 150 °C i. vac. Yield 0.25 g (45%). The blue-reddish F4PcZn was purified by zone sublimation at 10 -10 mbar (350 °C) and obtained as a mixture of regioisomers. UVA is (thf) X = 660 nm. MS (DCI, negative, NH3) m/z 648 (M ). 

In the Phillips process, polyphenylene sulfide (PPS) is obtained from the polymerization mixture in the form of a fine white powder, which, after purification, is designated Ryton V PPS. Characterization of this polymer is complicated by its extreme insolubility in most solvents. At elevated temperatures, however, Ryton V PPS is soluble to a limited extent in some aromatic and chlorinated aromatic solvents and in certain heterocyclic compounds. The inherent viscosity, measured at 206°C in 1-chloronaphthalene, is generally 0.16, indicating only moderate molecular weight. The polymer is highly crystalline, as shown by x-ray diffraction studies (9). The crystalline melting point determined by differential thermal analysis is about 285°C. 

Purification of the products is best effected by sublimation at 400°C in vacuo. However, not all phthalocyanines will sublime recrystallization from chlorobenzene, quinoline, or chloronaphthalene may then be employed. Certain more soluble phthalocyanines may be Soxhlet-extracted with lower boiling solvents such as acetone or alcohol. 

The halides vary in hydrolytic stability. Thus the fluoride is not hydrolyzed by refluxing aqueous ammonium hydroxide, while the chloride hydrolyzes completely in 45 hours and the iodide in 45 minutes. The complexes increase in solubility in chloronaphthalene in the sequence F < Cl < I, which is interpreted to imply increasing covalent character to the bond, in that sequence (195). The variation in hydrolytic stability has also been interpreted in terms of increasing covalent character. The hydrolytic stability of the fluoride may also be due to its low solubility which renders attack by hydroxyl groups kinetically very slow. 

The polymerization of the gaseous monomer (bp, 13.9°C) can be performed in solutionv in emulsion, and in suspenrion the polymer is obtmned in the form of a fine powder. It is only difficulty soluble, and elevated temperatures and special solvents such as chloronaphthalene, dibutyl phthalate, tricresyl phosphate, and benzyl benzoate must be ployed. In order to achieve better solubility in a larger number of solvents, the polymers are often subjected to finther treatment, which consists in an afterchlorination, a treatment with acids, or milling. Increased solubility of the polymer is also attained by solution polymerization at high pressures and temperatures. Polyvinyl chloride is insoluble in its own monomer. 

The pol5mier has a broad compatibiUty with chemicals and solvents, offering a better chemical resistance than stainless steel. No solvent for PPS is known below 200°C. Above this temperature, 1-chloronaphthalene is a suitable solvent. Molecular mass, characterization e.g., by size exclusion chromatography at moderate temperatures can be done only when derivatives are formed prior to analysis in order to enhance the solubility. The sulfide groups are oxidized, by a mixture of nitric acid and methanesulfonic acid resulting in a poly(p-phenylene sulfoxide) (PPSO) polymer. Actually, methanesulfonic acid is a solvent for PPSO. 

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