Ozonisers


Ozone is normally produced by the use of a silent electrical discharge and a number of ozonisers have been produced. Brodie s apparatus is shown in outline in Figure 10.2.  [c.263]

Using a potential of approximately 20(X)0 V the ozonised oxygen produced can contain up to 10% ozone and pure ozone can be obtained by liquifaction of the mixture followed by fractional distillation (O2, b.p. 90 K O3, b.p. 161 K).  [c.263]

VI,14. OXIDATION OF UNSATURATED COMPOUNDS WITH OZONISED OXYGEN (OZONOLYSIS)  [c.888]

For the determination of the structure of unsaturated compounds, oxidation with ozone (as ozonised oxygen) possesses many advantages. Ozonolysis, unlike oxidation with excess of permanganate or chromic acid which, for example, will also oxidise primary and secondary alcohols, is a highly specific process. By passing ozonised oxygen through a solution of an ethylenio compound in an inert solvent, preferably at a low temperature, ozone adds on readily and quantitatively to the double bond to give an ozonide (I)  [c.888]

The general method of ozonisation consists in passing dry ozonised oxygen through a dilute solution of the ethylenic compound In a solvent such as ethyl acetate, glacial acetic acid, chloroform, carbon tetrachloride, hexane or ethyl chloride, cooled in a freezing mixture (preferably at —20° to —30°). A wash bottle charged with potassium Iodide solution and boric acid is attached to the outlet tube of the bottle containing the solution of the substance the completion of the ozonisation is indicated by a sudden extensive separation of iodine. The following procedures may be used for decomposing the resulting ozonides —  [c.889]

A commercial form of ozoniser is illustrated in Fig. VI, 14, 1 this produces about 170 ml. of ozonised oxygen, containing 6-7 per cent, of ozone, per minute. The apparatus consists of ten ozone tubes, each with its own effective annular space, bridged in parallel across an inlet and outlet manifold. The units are suspended in a lead-lined, hardwood tank fitted with a terminal a ten-rod multiple high tension electrode, also fitted with a terminal, dips into the ozone tubes. The two terminals are connected by ozone-proof high tension leads to a transformer at 7,500 volts. The ozone tubes and tank are partially filled with 0 2 per cent, copper sulphate solution. Upon passing the silent high tension discharge across the annular space in the ozone tubes through which oxygen is flowing at a suitable ratef, ozone is formed in 6-7 per cent, yield.  [c.890]

It must be emphasised that on the outlet side of the ozoniser, the use of grease and/or rubber at any joint must be avoided. Unlubricated ground glass joints should be used PVC tubing may be employed for connexions. The ozonolysis is conducted in a wash-bottle of suitable size provided with a ground glass head it should be surrounded by a freezing mixture, preferably solid carbon dioxide and ether, contained in a Dewar vessel. This bottle should be connected to a similar, but smaller, wash bottle charged with acidified potassium iodide solution to indicate when the reaction is complete.  [c.890]

A simple semimicro laboratory ozoniser is illustrated in Fig. VI, 14, 2 this gives reasonably satisfactory results for small quantities of organic  [c.890]

Organic peroxides are highly explosive, hence it is best to carry out the ozonisation in a solvent which dissolves both the original compound and the ozonide.  [c.891]

Dissolve 8 -2 g. of cyclohexene (Section 111,12) in 200 ml. of pure dry ethyl acetate (Section II,47,2S) contained in a 500 ml. glass-stoppered wash bottle, cool the solution to —20° to —30° or below (e.y., with solid carbon dioxide - acetone) and attach the wash bottle through a calcium chloride or cotton wool drying tube to another containing acidified potassium iodide solution. Pass ozonised oxygen until the reaction is complete, i.e., until iodine is abundantly liberated. Then add 0 5 g. of palladium - calcium carbonate catalyst, and hydrogenate the cold solution of the ozonide in the usual manner (compare Fig. Ill, 150, 1) cool the hydrogenation vessel in ice. FUter off the catalyst, remove the solvent (Fig. II, 13, 4 but with a Claisen flask provided with a fractionating side arm) at normal pressure. Distil the residue under reduced pressure and collect the adipic dialdehyde at 92-94°/12 mm. The yield is 7 g. This aldehyde oxidises readily and should be kept in a sealed tube in an atmosphere of nitrogen or carbon dioxide. It may be converted into the dioxime by warming with aqueous hydroxylamine acetate solution after. recrystaUisation from water, the dioxime has m.p. 172°.  [c.892]

Dissolve 7 g. of pure oleic acid in 30 ml. of dry ethyl chloride (chloroform may be used but is less satisfactory), and ozonise at about —30°. Remove the solvent under reduced pressure, dissolve the residue in 50 ml. of dry methyl alcohol and hydrogenate as for adipic dialdehyde in the presence of 0 5 g. of palladium - calcium carbonate. Warm the resulting solution for 30 minutes with a slight excess of semicarbazide acetate and pour into water. Collect the precipitated semicarbazones and dry the  [c.892]

A synthesis of possible biological significance was effected by Spath and Berger, who ozonised eugenol methyl ether to 3 4-dimethoxyphenyl-acetaldehyde (Villa), which was then condensed with 3 4-dimethoxy-phenylethylamine (Vlllb), and the resulting Schiff s base (IX) treated wit hot 19 per cent, hydrochloric acid, whereby it was transformed into  [c.185]

Harries and Comberg have also supplied much evidence, which, taken with the above-mentioned researches, places the chemical isomerism of citronellol and rhodinol practically beyond dispute. By ozonisation experiments decomposition products were obtained, which proved that natural citronellal, obtained from citronella oil, is a mixture of about  [c.120]


See pages that mention the term Ozonisers : [c.889]    [c.890]    [c.891]    [c.141]    [c.141]    [c.141]    [c.144]    [c.191]    [c.258]    [c.347]    [c.348]    [c.356]    [c.357]    [c.359]    [c.360]    [c.367]    [c.368]    [c.370]    [c.407]    [c.409]    [c.436]    [c.474]    [c.580]    [c.590]    [c.624]    [c.121]    [c.330]   
Textbook on organic chemistry (1974) -- [ c.890 , c.891 ]