Dissolved organic halide

Table 13. Electrochemical carboxylation of organic halides at dissolving metal anodes [174]...

The Matrix TiOa photocatalytic treatment system is a technology that destroys dissolved organic contaminants in water in a continuous-flow process at ambient temperature. The technology uses ultraviolet (UV) light and a titanium dioxide (TiOa) semiconductor catalyst to break hydroxide ions (OH ) and water (H2O) into hydroxyl radicals (OH ). The radicals oxidize the organic contaminants to form carbon dioxide, water, and halide ions (if the contaminant was halogenated). 

Dissolve 37.5 g (0.25 mol) of dry sodium iodide (1) in 250 ml of dry acetone in a 500-ml flask fitted with a reflux condenser protected by a calcium chloride guard-tube, and add 30.2 g (25 ml, 0.2 mol) of l-bromo-3-methylbutane. A precipitate of sodium bromide soon begins to form leave the reaction mixture at room temperature for 30 minutes, and then boil under reflux for 45 minutes to complete the reaction. Allow to cool and filter off the sodium bromide, washing the residue with a little acetone. Remove the acetone from the filtrate on a rotary evaporator, and shake the residual organic halide with 100 ml of water. Separate the lower dark-coloured layer and wash it twice more with 50 ml portions of water incorporate sufficient crystals of sodium thiosulphate into the first portion of wash-water to decolourise the organic phase. Dry the product over anhydrous calcium sulphate, filter and distil, collecting the l-iodo-3-methylbutane at 145-147 °C. The yield is 26 g (66%). 

This simple example may illustrate that in general the reaction of an organic halide salt [cation]X with an excess of a Lewis-acid MXy can result in new catalytic materials even if other Lewis-acids are applied than AICI3. In contrast, the use of other Lewis-acids to form the ionic liquid of type [cation][MXy+i] + excess MXy (the excess of MXy may be dissolved in the neutral ionic liquid or may form acidic anionic species such as e.g. [M2X2y+i]-) gives access to new combinations of properties (e.g. a liquid, less oxophilic, Lewis-acidic catalyst with defined solubility and acidity properties). In Table 2 other examples of ionic liquids are presented which are formed by the reaction of an organic halide salt with different Lewis-acids. All these systems should be in principle useful acidic catalysts for synthetic organic chemistry even if not all displayed examples have been already discribed in the literature for this application. 

Carbon monoxide, when passed over a heated catalyst, such as iron oxide, dissociates to form carbon dioxide and an activated carbon.54,55 Mercury and other metals react with organic halides to produce metallic halides and carbon.56 Stratton and Winkler57 describe a method in which hydrocarbons are burned in chlorine the carbon produced is activated by heating to 1,000° C for an hour. Simons and McArthur58 observed that activated carbon is formed by the action of oxygen on aromatic, alicyclic, and aliphatic compounds dissolved in liquid hydrogen fluoride. 

Reactions of dissolved organic compounds with solid inorganic compounds, particularly metals and metal halides, to metal-organic compounds. 

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