Question

Diazo coupling is useful to prepare_____________

Answer 1

We need to know that the phenol is one of the mono substituent benzene compounds. Each mono-substituent moiety has three named positions in the ring. In the ring a nearby mono substituent group is called ortho position, that means two ortho positions are in the ring, because of the left and right side of the substituent group. The alternatively position of the substituent group in the ring is called meta position, here also two meta positions possible in the left and right side of the substituent group. Para position is nothing but directly opposite to the substituent group in the ring. Electrophilic substitutions are attacked in ortho and para position in the ring.

Complete answer:
As we know that the diazo coupling is useful to prepare some color dyes.
When phenol and aromatic compounds react benzene diazonium salts to give the product of diazo compounds. These diazo compounds will form required for highly reactive aromatic benzene moiety.
The colour of diazo compounds is due to the double bond between the two nitrogen atoms in the molecular formula. Because these double bonds in between the two nitrogen atoms act as the chromophore group. The chromophore groups are the reason for the colour of the compound.
According to the above discussion, we conclude diazo coupling is useful to prepare some color dyes.

Note:
We need to know that the atomic number of nitrogen is $7$ and the total number of electrons is$7$and the symbol of nitrogen is ${\text{N}}$. In these seven electrons, the first two electrons are going to fill in the first energy level $1{s^2}$. The remaining five electrons are going to fill in the second energy level. In these five electrons two electrons are going to fill in$2{s^2}$ and three electrons are filling each electron in $2p_x^12p_y^12p_z^1$. The number of electrons in the atom is equal to the atomic number of the atom. The electron fills in the atomic orbital of the atom. The electron fill in the atomic orbital is followed by the three important principles. There is the Pauli exclusion principle, Aufbau principle and Hund’s rule.