Aromatic solvents, metalation

Metal-free copper phthalocyanine blue, ie. Pigment Blue 16 [574-93-6] is one of the eadiest forms of phthalocyanine. Environmental concerns about copper in pigments tended to increase the use of metal-free copper phthalocyanine, but certain shortcomings (greenish hue, lack of stabiHty in aromatic solvents) allowed only specialty uses (109). The stabiH2ed a-NC-type is used in certain automotive coatings. 

Dry methylene chloride does not react with the common metals under normal conditions however, a reaction with aluminum can be initiated, sometimes explosively, by the addition of small amounts of other halogenated solvents or an aromatic solvent (7). Iron catalyzes the reaction, and this can be significant in the handling and storage of methylene chloride and in the formulation of products, eg, in aluminum aerosol containers of pigmented paints, where the conditions necessary for the reaction are commonly found. A typical reaction in this process is shown in equation 2. 

An excess of metal is used because aromatic solvents are reduced to some extent and it is easier than weighing out the exact amount. 

Storage stability Extremely unstable in presence of trace metals or other impurities. Traces of iron chloride may cause explosive decomposition. Pure material is stable for only 1 or 2 months. It may be stabilized by nitromethane, chloropicrin, glycine, ethyl acetate, or ether - but only in glass vessels below 20°C. Apparently, it is most stable in aromatic solvents. 

Precious metals Mixed chloride solution (Au, Pt, Pd) 8-Hydroxyquinoline derivatives in aromatic solvent... 

Compound 35 does not form above 30°C when an aromatic solvent is used instead, two alkynes are dimerized to give a titanacyclopentadiene having the structure of l,l-bis(r 5-cyclopentadienyl)-2,3,4,5-tetraphenylzirconole (36) (Fig. 15). It is an important intermediate in alkyne oligomerization reactions on transition metal complexes. 

Although the first bis(iminophosphorano)methanides were reported by Elsevier,15 the first structurally characterised examples were reported by Cavell.16 Solvent-free 1 and 2 were prepared from the reaction between the parent methane and lithium or sodium bis(trimethylsilyl)amides in aromatic solvents. By avoiding Lewis base solvents such as ethers, dimeric complexes were isolated. Treatment with excess quantities of alkali metal amide did not effect a second deprotonation, even under reflux conditions over days, which was attributed to the less basic nature of amides compared to alkyls (see section 3.2 below). In addition to the expected methanide-alkali metal bonds, methine C H — Li interactions were observed in 1 in the solid state but the analogous C-H — Na interactions appeared to be weak in 2. 

All the compounds in Table II are soluble in aromatic solvents. They are all moderately air-sensitive, and the arsine and stibine complexes are thermally unstable, decomposing upon standing in solution—or more slowly in the solid state—to liberate nickel metal. 

The dimeric trihalides form discrete molecules (Fig. 6-2). The halides dissolve readily in aromatic solvents such as benzene, in which they are dimeric. As Fig. 6-2 shows, the configuration of halogen atoms about each metal atom is far from ideally tetrahedral. The formation of such dimers is attributable to the tendency of the metal atoms to complete their octets. 

A very stable type of organocopper compound, a metalated ylide, is obtained from the reaction between copper(I) chloride and trimethyl-methylenephosphorane in an aromatic solvent. The compound is soluble in aromatic and chlorocarbon solvents and can be sublimed 256a). 

The standard method for synthesis of polysilanes follows the original preparation of (Me2Si) by Burkhard. Diorganodichlorosilanes are treated with finely dispersed sodium metal in an inert diluent, usually above the melting point of sodium. Homopolymers are obtained from single dichlorosilanes, while cocondensation of mixtures of dichlorosilanes yields copolymers (equation 33). Toluene is the most commonly used solvent, but other aliphatic or aromatic solvents are also effective. After completion of the reaction, the mixture is quenched with alcohol and/or water to destroy any excess sodium and silyl anion, then filtered and... 

Is an O/W balanced emulsifier for petroleum oils, vegetable oils, and solvents. It functions as an emulsifier for oil based metal lubricants and textile processing aids and is a superior emulsifier component for aliphatic and aromatic solvents in low foaming textile dye carriers. 

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