Diatomic alcohols

Glycol.—Of diatomic alcohols only glycol seems to have been the subject of investigation. Renard3 observed in the... 

Practically, the fixation of the mono- or diatomic alcohols or of the diol is achieved by heating silica with an excess of alcohol, either in an autoclave at 150°C, for low boiling point alcohols, or directly using alcohols having boiling points over 150 C [lOj. 

There is as yet only one alcohol known containing a trivalent radical This is glycerin, whose relation to the mouoatomic and diatomic alcohols is shown by the following formulse ... 

The acids possibly derivable from benzene by the substitution of (COOH), or of (COOH) and (OH), for atoms of hydrogen, would form, were they, all known, a great number of series there are, however, comparatively few of them which have been as yet obtained, although the number of acid series known is greater than that of corresponding alcohols. Each series of mono- and diatomic alcohols furnishes a corresponding series of acids, thus ... 

Terpin—CioH, ,2HaO—is formed by the dehydration of terpin hydrate (q.v.). It is crystalline, fusing at 103° (217°.4 F.), capable of sublimation, and boils at about 250° (482° P.). It absorbs HjO eagerly to form terpin hydrate. It behaves like a diatomic alcohol, and is converted intoterebenthene dichlorhydrate, by gaseous HCl, or by PC1 . It is dehydrated by PjO , and converted into terebene and colophene. 

Alcohols which contain two hydroxyl groups are named in a similar way. The number of hydroxyl groups is indicated by prefixing the syllables di, tri, etc., to the termination ol. Thus, the diatomic alcohol CH3.CHOH.CH2OH is called 1, 2-propanediol. 

As a result of the reaction the hydrogen in the hydroxyl group in alcohol is replaced by the acetyl group. If a diatomic alcohol is used two acetyl groups are introduced. The reaction is of great analytical value as by means of its use the number of hydroxyl groups present in a substance of unknown structure can be determined. 

On the basis of the obtained results it is possible to make the following conclusion. The kinetics of ozone consumption in the reaction with the PVA described by the second order reaction law (the first - on ozone and the first - on substrate). Similar pattern, as noted above, is typical for ozone oxidation of mono- and diatomic alcohols in the field of small concentrations of the substrate and it is not typical for the oxidation of alcohols with higher atomicity (with the number of OH-groups n > 3) - glycerine, ethriole, pentaerythritol and mannitol. Obviously, here is implemented the following ratio k + k3[S] K (see the scheme at the beginning of the article). Thus, all the obtained complexes S—O3 ([S—O3] [O3]) are transformed into products and, consequently, the rate of ozone consumption is determined by the rate of the reaction (1) ... 

In summary, the interaction of ozone with molecules of substrate (reaction 1) is the limited step of the process of ozone oxidation of PVA as well as for mono- and diatomic alcohols. 

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