Ether type solvent

Actinide ions form complex ions with a large number of organic substances (12). Their extractabiUty by these substances varies from element to element and depends markedly on oxidation state. A number of important separation procedures are based on this property. Solvents that behave in this way are thbutyl phosphate, diethyl ether [60-29-7J, ketones such as diisopropyl ketone [565-80-5] or methyl isobutyl ketone [108-10-17, and several glycol ether type solvents such as diethyl CeUosolve [629-14-1] (ethylene glycol diethyl ether) or dibutyl Carbitol [112-73-2] (diethylene glycol dibutyl ether). 

The addition product, C QHgNa, called naphthalenesodium or sodium naphthalene complex, may be regarded as a resonance hybrid. The ether is more than just a solvent that promotes the reaction. StabiUty of the complex depends on the presence of the ether, and sodium can be Hberated by evaporating the ether or by dilution using an indifferent solvent, such as ethyl ether. A number of ether-type solvents are effective in complex preparation, such as methyl ethyl ether, ethylene glycol dimethyl ether, dioxane, and THF. Trimethyl amine also promotes complex formation. This reaction proceeds with all alkah metals. Other aromatic compounds, eg, diphenyl, anthracene, and phenanthrene, also form sodium complexes (16,20). 

Gallium trichloride is a solid (mp 78-79°) which reacts with air. It is soluble in both hydrocarbons and ether-type solvents. Both the solid compound and its solutions can be stored in a waterfree environment for relatively long periods. Gallium trichloride undergoes typical metathetical displacement of one, two, or all three chlorine atoms in reactions with one, two, or three molar equivalents of an alkyllithium compound, respectively 4... 

Dioxane (bp 101°) is another useful ether-type solvent and is particularly suitable for some reactions since it is completely miscible with water and can therefore be easily removed at the completion of the reaction. Commercial dioxane contains water, glycol acetal, and peroxides, all of which should be removed. Three liters of dioxane, 40 ml of concentrated hydrochloric acid, and 300 ml of water are heated to reflux in order to hydrolyze the acetal, and a stream of nitro-... 

An example of the donor-acceptor initiation process is demonstrated by the sodium-naphthalene system devised by Szwarc [13]. The initiation sequence begins with the transfer of an electron from sodium metal to naphthalene. In an ether-type solvent, such as tetrahydrofuran (THF) sodium naphthalide. 

This solid, which is stable in dry air up to 300°, is a less powerful reducing agent than lithium aluminium hydride, from which it differs also by being soluble in hydroxylic solvents and to a lesser extent in ether-type solvents. Sodium borohydride forms a dihydrate melting at 36-37°, and its aqueous solutions decompose slowly unless stabilised to above pH 9 by alkali. (For example, a useful sodium borohydride solution is one that is nearly saturated at 30-40° and containing 0.2% sodium hydroxide.) Its solubility in water is 25, 55 and 88g per lOOmL... 

Ferricinium perchlorate, nitrate, and chloride are readily soluble in water and alcohols, somewhat soluble in hydrocarbons, but insoluble in ether-type solvents. The ferricinium ion is blue, and it may be precipitated from solution as the triiodide, tungstosilicate, picrate, reineckate, etc. Ferricinium salts may be reduced to ferrocene by tin(II) chloride. 

Methyl isobutyl ketone, methyl ethyl ketone, acetone, dimethylformamide, tetrahydrofuran, l-methyl-2-pyrrolidine, acetonitrile and related polar solvents Freon and freon ether type solvents are best for the more heavily (8) fluorinated polymers... 

Alkyl halide, sodium hydride in ether-type solvents 2.6 General preferred over procedures 2.4 and 2.5 when substrates are soluble in ether-type solvents As for procedure 2.4 For the derivatization of highly reactive (unctions, sodium hydride may be replaced with potassium carbonate (see procedure 2.16.3 and Ref 138) 1,2-dimethoxyethane is the preferred solvent... 

Alkylation with alkyl halides and sodium hydride in ether-type solvents... 

The solution of the substrate (preferably in an ether-type solvent) is treated with a solution of the triazene (1.1 equiv per H to be replaced, or a larger excess for groups assumed to be less reactive) and the reaction mixture is stirred for Ih while nitrogen is evolved. When the conversion is complete, as often indicated by ceased efiervescence, excess of the reagent is destroyed by careful addition of 10% hydrochloric acid. The mixture is quantitatively transferred into a separating funnel and washed successively with 10% hydrochloric acid, then wi th a dilute solution of sodium bicarbonate, and finally with water. The organic phase is dried over a suitable desiccant and concentrated. 

Freon and freon ether type solvents are best for the more heavily fluorinated polymers (8)... 

Concerning the polymer, the main problem is the difficulty to find suitable solvents for PACA characterization, especially for the determination of their MW. The strongly polar solvents (nitromethane, acetonitrile and DMF) dissolve the polymers from methyl, ethyl and w-butyl esters (PMCA, PECA, PBCA), but they are suspected to cause degradation. Ether-type solvents are supposed to be inert, thus suitable. THF is indicated only for PBCA, since PMCA is insoluble, and PECA of high MW in THF shows a high viscosity and GPC anomalies. 

Each ether-type solvent has distinct physical and chemical properties as well as specific toxicology characteristics. Specific toxicology information on a ether solvent is available in the solvent s MSDS and from the solvent producer. 

The cardinal rule for proper disposal of any organic solvent applies to the ether-type solvents. Do not dump any solvent into any sewers, on the ground, or into any body of water. 

The first step in the reaction sequence is generally called a hydroboration The addition of diborane is a rapid, quantitative, and general reaction for all alkenes (as weU as alkynes) when carried out in a solvent that can act as a Lewis base. The ether solvation of the diborane, for example, is the key to the success of this reaction. In the absence of a Lewis base, borane (BH3) exists as a dimer (B2H6), which is much less reactive than the monomer (BH3). Borane, however, does exist in coordination with ether type solvents. It is the monomer (BH3) that functions as the active reagent in the reductive addition. 

Just like carbonates, ether-type solvents are not stable in comparison to metal lithium, and are reduced at the negative electrode. However, they cause the formation of a stable passivation layer at the SEI, which ultimately helps to protect the negative electrode. In general, ether-type solvents can be employed in all types of lithium batteries. However, the electrochemical stability of ethers against oxidation is not as good as that of carbonates (<4 V versus LE/LI as opposed to 4.5 V versus Li Li for carbonates), which is why they are very infrequently used. However, this window of stability is perfectly compatible with the Li-S battery (cycled between 1.5 and 3 V). 

In these direct reactions of metals such as lithium, magnesium, sodium, potassium and zinc, using sonochemistry, in which the surface of the metal is activated by irradiation by ultrasonic waves, has recently been performed [22,23]. For example, n-PBr [24], -BuBr [25] or PhBr [25] reacts with lithium metal in an ether type solvent (ethyl ether or THF) at —10 or — 60 C for 90 or 180 min in the absence of ultrasonic waves and the yields of /i-PrLi, /i-BuLi and PhLi are 78, 56 and 92 %, respectively. However, in the reactions under ultrasonic waves used for 10-30min, the yields are 90%, 61 % and 95%, respectively as shown in eq. (3.3) [23]. 

The capability of neutral-carrier-type ion selective electrodes is considered to be dependent on its functional characteristics as an ionophore of the neutral carrier itself and on the compatibility of the carrier into the PVC membrane containing membrane solvent and lipophilic salt. At first, effects of membrane solvents on the sensitivity and selectivity of the Na" " selective electrodes based on six of the calix[4]arene derivatives 1-6, were determined. The membrane solvents tested were NPOE and FPNPE as the phenyl ether type solvents and DOP as the diester type one. Selectivity coefficients for Na" " ion with respect to other alkali and alkaline-earth metal ions, NH4 and H on the electrodes based on derivative 2 are summarized in Table I. 

W. S. Kim, S. Hosono, H. Sasai, M. Shibisaki Heterocycles 1996, 42, 795—perchlorate counter-ions have been proposed to provide higher a-selectivities than triflates owing to their slightly reduced fugacity and ether type solvents at room temperature also serve to promote a-selectivity (see chapter on solvent effects). 

Grignard reagents, organomagnesium halides, are prepared by the reaction of metallic magnesium with a wide range of organic halides (reaction 9.3). Dry ether type solvents are essential. 

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