Why direct iodination is not possible?

Direct iodination of alkanes is not possible because the by-products \( HI\) reduced ion alkane back to alkane. Hence, strong oxidizing agents like iodic acid, Nitric acid which destroys \( HI\) and prevent the reversibility of the reaction.

What is benzene iodination?

Iodination of benzene is a two-step electrophilic aromatic substitution reaction in which benzene is treated with iodine, resulting in the formation of new carbon-iodide bond. In this electrophilic aromatic substitution reaction, an electrophile attacks the benzene which results in the substitution of hydrogens.

Is iodination of benzene reversible?

When benzene is reacted with iodine the reaction is reversible in nature. It leads to the formation of reactants back.

How do you chlorinate benzene?

Benzene reacts with chlorine or bromine in the presence of a catalyst, replacing one of the hydrogen atoms on the ring by a chlorine or bromine atom. The reactions happen at room temperature. The catalyst is either aluminum chloride (or aluminum bromide if you are reacting benzene with bromine) or iron.

Why direct fluorination and iodination reaction of alkanes are not possible?

Why is the direct fluorination and iodination of alkanes via a free radical mechanism not possible? – Quora. Fluorination of alkanes is highly exothermic which may explode. Iodination of alkanes is reversible reaction,as HI so produced is stronger reducing agent,it attacks on Alkyl iodides produced.

Why does the iodination of benzene require the presence of strong oxidising agent?

Give reason. The iodination of benzene is a reversible reaction. Therefore, yield of C6H5I is very poor because HI combines with C6H5I and forms back the reactants. In the presence of oxidizing agent like HIO3 or HNO3, the co-product HI is oxidised to iodine and iodination proceeds favourably in the forward direction.

Why is the reaction of benzene with iodine not possible in presence of AlCl3?

This is because the electronegativity of iodine is less than that of chlorine. The iodonium ion acts as an electrophile. We know that benzene is a planar molecule and has a cloud of delocalised electrons above the plane of the ring.

Why is iodination of benzene carried out in the presence of nitric acid or iodic acid?

Is iodination a reversible process?

Iodination of alkanes is reversible.

Why does benzene does not react with bromine?

The six electrons in the π-system above and below the plane of the benzene ring are delocalised over the six carbon atoms, so the electron density is lower. The bromine cannot be polarised sufficiently to react, and the lower electron density does not attract the electrophile so strongly.

Why is direct iodination of benzene not possible?

Direct iodination of benzene is not possible because the reaction is reversible and the HI so produced in the reaction is a very strong reducing agent which reduces iodobenzene back to benzene. Similarly, why benzene does not react with bromine?

What happens when HIO3 is added to benzene?

This is because, I 2 adds to the Benzene reversibly generating HI. HI being a strong reducing agent regenerates I 2 from aryl iodide giving back the aromatic hydrocarbon. However, in the presence of oxidizing agents such as HIO 3, HI is converted back to Iodine thereby increasing the concentration of Iodine in the reaction mixture.

Why is the reaction between benzene and nitric acid carried out?

Hence, this reaction is carried out in the presence of a strong oxidising agent like iodic acid or nitric acid, that oxidises the HI formed in the reaction to iodine, enabling the reaction to proceed in the forward direction. Was this answer helpful? Benzene is resonance stabilised, so it has low tendency to form a – ve ion.

How to reduce iodobenzene with Hihi?

HI reduces produced iodobenzene to benzene again. This problem can be solved by adding strong oxidizing agent (HIO3,HNO3 etc.) to the reaction mixture so that produced HI can be neutralized and consumed, it will not be further available for reduction of iodobenzene. And the proper amount of product is formed.