Citric acid, being tribasic, forms either acid monometallic, acid dimetallic or neutral trimetallic salts; thus, mono-, diand tri-potassium and sodium citrates are known.
Group III.: B, trivalent; Al, trivalent, but possibly also tetra-or penta-valent; Ga, divalent and trivalent; In, mono-, diand tri-valent; Tl, monovalent and trivalent..
The orientation of higher substitution derivatives is determined by considering the diand tri-substitution compounds into which they can be transformed.
The action of chlorine upon diand tri-oxybenzenes has been carefully investigated by Th.
The nitro group has a very important action mainly on account of the readiness with which it can be introduced into the molecule, but its effect is much less than that of the azo group. The colour produced is generally yellow, which, in accordance with a general rule, is intensified with an increase in the number of groups; compare, for example, mono-, diand tri-nitrobenzene.
The reaction proceeds in several stages, mono-, diand finally tri-nitrate being produced, the final stage requiring sulphuric acid as a dehydrator.
Cannizzaro, Ann., 1865, 1 34, p. 128), but diand tri-benzylamines are simultaneously formed.
The diand tri-methyl derivatives are found in the fusel oil obtained by fermentation of beetroot sugar.
With ammonia they yield complex condensation products; acetone forming diand tri acetonamines (W.
Numerous mono-, diand trisulphonic acids of a-naphthol are employed in the preparation of azo dyes.
Hydrobromic acid at 185°-190°C. converts it into diand tri-bromaniline.
It is obtained by condensing benzal chloride with mercury diphenyl (Kekule and Franchimont, Ber., 1872, 5, p. 907); from benzal chloride or benzotrichloride and zinc dust or aluminium chloride; from chloroform or carbon tetrachloride and benzene in the presence of aluminium chloride; and deamidating diand tri-aminotriphenylmethane with nitrous acid and alcohol (0.
On heating it gives the diand penta-chlorides.
Nitrogen), the mono-, diand trioxides being basic in character, the tetraand pentoxides being acidic and also feebly basic. The monoxide, V 2 0, is formed when the metal is oxidized slowly in air.
These acids are obtained by the reduction of the hydrobromides of the diand tetra-hydroterephthalic acids or by the action of ethylene dibromide on disodio-butane tetracarboxylic acid.
A r It is reduced by the action of zinc and ammonia to diand tetra-hydroquinolines.