The diazo solution is prepared by dissolving p-aminophenol or its hydrochloric in a little dilute hydrochloric acid, cooling in ice and carefully diazotising in the cold till a slight excess of nitrous acid is present.
Cinnolin derivatives are obtained from oxycinnolin carboxylic acid, which is formed by digesting orthophenyl propiolic acid diazo chloride with water.
Somewhat later, they found that it could be prepared from diazobenzene imide, provided a nitro group were present in the ortho or para position to the diazo group.
If before the diazo solution is used a quantity of acetate of soda be added to it, the free hydrochloric acid liberates acetic acid from the acetate, and the chloride of the diazo body changes into its acetate.
It has been found by experience that the colour is developed much brighter upon the fibre when the diazo solution contains acetic acid and no free mineral acid.
Now the diazo compounds are rather unstable bodies, but they have a great affinity for other compounds, such as naphthol, phenylene diamine, phenol, and combine easily with them when brought into contact with them.
The diazo compounds formed on the fibre are not very stable bodies.
As the cotton yarn is being passed through the developing bath, the latter is freshened up from time to time by suitable additions of the diazo and acetate liquors in the proportions given above.
The developing bath is made by taking 4 gallons of the diazo liquor and 1 gallon of the acetate liquor and mixing together, and in this bath the prepared yarn, 2 lb.
Those most in use are beta-naphthol for red from Primuline, and for bluish blacks from Diamine blacks, Diazo blacks, Zambesi blacks, etc.
By the action of nitrous acid upon the salts of the primary organic amines the so-called diazo compounds are formed.
A diazo salt is formed, and is then made to react in solution with a hydroxy compound or an amino compound, &c.
Diazo salts are crystalline compounds soluble in water, sparingly soluble in alcohol, and are unstable, decomposing explosively if struck or suddenly heated.
Diazo salts are valuable in the synthesis of different classes of compounds, as the - N:N - group reacts readily with other groups.
The diazo group may also be exchanged for the hydroxyl group by warming the solution with water, or for the cyanogen group by warming with a solution of potassium cyanide, e.
Diazo compounds are therefore important intermediate substances in the manufacture of azo dyes.
To subject to such reactions or processes that diazo compounds, or their derivatives, shall be produced by chemical exchange or substitution.
Diazo compounds are in general unstable, but are of great importance in recent organic chemistry.
Ordinarily the diazo appears a little earlier than the Widal reaction--about the fourth or fifth day--but it may be delayed.
The diazo reaction has been obtained in many forms of the disease.
The most important of these are proteids, sugars, acetone and related substances, bile, hemoglobin, and thediazo substances.
The dyed colour here plays the part of a phenol or amine, and reacts with the diazo compound to produce a new colour.
The necessary diazo compound is prepared by allowing a solution containing nitrous acid to act upon a solution of a primary aromatic amine.
It is usually desirable to keep the solutions cool with ice, owing to the very unstable nature of the diazo compounds produced.
These are certain Direct Colours, dyed on cotton in the ordinary manner, which are then developed by passing into a diazo solution--e.
The colour obtained varies according to the particular diazo compound, as well as the amine or phenol employed, [beta]-naphthol being the most useful among the latter.
The Insoluble Azo Colours are produced as insoluble coloured precipitates by adding a solution of a diazo compound to an alkaline solution of a phenol, or to an acid solution of an amido compound.
The same coloured precipitates are produced upon the cotton fibre if the material is first impregnated with an alkaline solution of the phenol, then dried and passed into a cold solution of the diazo solution.
In general they arediazo and sulphonic acid derivatives of benzene and naphthol.
The potassium salt of the iso-diazo hydroxide yields on methylation a nitrogen ether, R.
These results point to the conclusion that the iso-diazo hydroxide is a tautomeric substance.
According to Hantzsch the isomeric diazo hydroxides are structurally identical, and the differences in behaviour are due to stereo-chemical relations, the isomerism being comparable with that of the oximes (q.
The constitution of thediazo fatty esters is inferred from the fact that the two nitrogen atoms, when split off, are replaced by two monovalent elements or groups, thus leading to the formula N \ .
H On adding the alkaline hydroxide to the solution, this hydrate is supposed to lose water, yielding the syn-diazo hydroxide, which then gives rise to a certain amount of the sodium salt (A.
The constitution of the isomeric diazo hydroxides has given rise to much discussion.
The first aliphatic diazo compound to be isolated was diazoacetic ester, CH.
Defn: A nitrogenous compound, C7H6N2, analogous to indol, and produced from a diazo derivative or cinnamic acid.
Defn: A combining form (also used adjectively), designating any one of a series of double derivatives of the azo and diazo compounds containing four atoms of nitrogen.
According to generally accepted views this should effect the removal of the diazo group and its replacement by hydrogen.
The reaction of HNaSO{3} on the diazo compound may be represented in two stages, the first portion forming an addition product and the second acting as a reducing agent.
Hence it was believed that if the hydrazine compound should be made from diazo compound mentioned above, the corresponding hydrocarbon, i.
By this the diazocompound is made first and isolated.
As many of these diazo compounds contain no oxygen their explosive nature must be ascribed to the peculiar state of union of the nitrogen.
Bichromates, although containing much available oxygen, form but feeble explosive mixtures, but some compounds of chromic acid with diazo compounds and some acetylides are extremely powerful as well as sensitive.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "diazo" in a variety of sentences. We hope that you will now be able to make sentences using this word.
