Toluene addition compound with

C, which leads to a break in the pressure-composition curve at BF3 Ir = 2 1. The formation of the 1 1 complex in solution is indicated by titrations. Insertion of InCl into the Fe—Fe bond in boiling dioxane yields [T7 -C CO)2Fe]2lnCl in 55% yield. The only group-VIIA compound that forms an addition compound with a group-lIIB halide, namely with BF3, is [(i7 -Cp)2ReH]The formation of (t -Cp),ReH BF3 is established when (T7 -Cp),ReH is titrated tensimetrically in toluene with BF3 at 0°C. 

Many aromatic hydrocarbons, for example, benzene, ethylbenzene, toluene, cymene and tetrahydronaphthalene, yield additive compounds.5 Such are also formed with liquid cyclic hydrocarbons in the absence of moisture and phenols, and use has been made of this fact to remove sulphur dioxide from a dry gas containing it.6 Additive compounds are also formed with methyl alcohol, thus CH30H.S02 and 2CH30H.S02, the existence of which has been demonstrated definitely by means of the freezing-point curve.7 The additive compound with camphor has already been mentioned (p. 109). 

These can be converted to their uranyl nitrate addition compounds. The crude or partially purified ester is saturated with uranyl nitrate solution and the adduct filtered off. It is recrystallised from -hexane, toluene or ethanol. For the more soluble members crystallisation from hexane using low temperatures (-40°) has been successful. The adduct is decomposed by shaking with sodium carbonate solution and water, the solvent is steam distilled (if hexane or toluene is used) and the ester is collected by filtration. Alternatively, after decomposition, the organic layer is separated, dried with CaCl or BaO, filtered, and fractionally distilled under high vacuum. 

Ketones are more stable to oxidation than aldehydes and can be purified from oxidisable impurities by refluxing with potassium permanganate until the colour persists, followed by shaking with sodium carbonate (to remove acidic impurities) and distilling. Traces of water can be removed with type 4A Linde molecular sieves. Ketones which are solids can be purified by crystallisation from alcohol, toluene, or petroleum ether, and are usually sufficiently volatile for sublimation in vacuum. Ketones can be further purified via their bisulfite, semicarbazone or oxime derivatives (vide supra). The bisulfite addition compounds are formed only by aldehydes and methyl ketones but they are readily hydrolysed in dilute acid or alkali. 

Substantially more work has been done on reactions of square-planar nickel, palladium, and platinum alkyl and aryl complexes with isocyanides. A communication by Otsuka et al. (108) described the initial work in this area. These workers carried out oxidative addition reactions with Ni(CNBu )4 and with [Pd(CNBu )2] (. In a reaction of the latter compound with methyl iodide the complex, Pd(CNBu )2(CH3)I, stable as a solid but unstable in solution, was obtained. This complex when dissolved in toluene proceeds through an intermediate believed to be dimeric, which then reacts with an additional ligand L (CNBu or PPh3) to give PdL(CNBu )- C(CH3)=NBu I [Eq. (7)]. 

The vinyl substituent at C-2 can also act as a Michael acceptor and reaction with certain nucleophiles gives rise to 1,4-addition compounds. For example, p-toluene-sulfonic acid catalyzed addition of thiols to 2-vinyl- or 2-isopropenyl-5(47/)-oxazolones 136 gave, almost exclusively, the Michael adducts 137 that were used... 

In the NMR spectrum integrated signals are exactly proportional to the number of contributing nuclei. The Comite Consultatif pour la Quantite de Matiere (CCQM) has started international comparison of quantitative NMR experiments. In the first round the possible reproducibility should be established. The composition of a mixture of organic compounds has been determined by integration of the NMR signals. Already the first experiments (Fig. 9) have shown the problems arising by isomerization (ethyl-4-toluene sulphonate), decomposition (1,3-dimethoxybenzene), purity of standard compound and superimposition of isotopic satellites. Additional experiments with a new composition are necessary. 

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