Dow's ReactionDow's reaction is a chemical reaction in which an alkene is reacted with carbon monoxide and hydrogen gas in the presence of a catalyst to form an aldehyde. The reaction was discovered by Herbert Henry Dow in 1891.Reaction MechanismThe reaction mechanism for Dow's reaction is as follows:1. Formation of a metal carbonyl complex: The metal catalyst (usually nickel) reacts with carbon monoxide to form a metal carbonyl complex.2. Adsorption of alkene: The alkene is adsorbed onto the surface of the catalyst.3. Formation of a metal-alkene complex: The alkene reacts with the metal carbonyl complex to form a metal-alkene complex.4. Addition of hydrogen: Hydrogen gas is added to the metal-alkene complex, which results in the formation of a metal-alkyl complex.5. Elimination of the metal carbonyl complex: The metal carbonyl complex is eliminated from the metal-alkyl complex, resulting in the formation of an aldehyde.Reaction TypeDow's reaction involves electrophilic addition. The alkene acts as the nucleophile, while the catalyst and carbon monoxide act as the electrophiles. The hydrogen gas acts as a reducing agent.ApplicationsDow's reaction is used in industry to produce aldehydes, which are used in the manufacture of various chemicals, such as plastics, resins, and solvents. It is also used in the synthesis of pharmaceuticals and fragrances.

As chlorine has electrons in excess and is not deficient in any way.. chlorine has negative charge and hence it shows necleophilic substitution....