Predict the products of the following S_N2 reactions.
(c)


(d)

Verified step by step guidance

1. Step 1: Identify the type of reaction. Both reactions are SN2 reactions, which involve a single-step mechanism where the nucleophile attacks the electrophilic carbon and displaces the leaving group simultaneously.
2. Step 2: Analyze the reactants in reaction (c). The nucleophile is the phenylthiolate ion (C6H5S⁻), and the electrophile is ethyl bromide (CH3CH2Br). The bromine atom is the leaving group.
3. Step 3: Predict the product for reaction (c). The phenylthiolate ion will attack the electrophilic carbon in ethyl bromide, forming a new bond between the sulfur atom and the ethyl group. Bromine will be displaced as Br⁻.
4. Step 4: Analyze the reactants in reaction (d). The nucleophile is the acetylide ion (Na⁺:C≡CH), and the electrophile is a long-chain alkyl chloride (CH3(CH2)8CH2Cl). The chlorine atom is the leaving group.
5. Step 5: Predict the product for reaction (d). The acetylide ion will attack the electrophilic carbon in the alkyl chloride, forming a new bond between the terminal carbon of the acetylide and the alkyl chain. Chlorine will be displaced as Cl⁻.

Key Concepts

S_N2 Mechanism

The S_N2 mechanism is a type of nucleophilic substitution reaction where a nucleophile attacks an electrophile, resulting in the simultaneous displacement of a leaving group. This reaction occurs in a single concerted step, leading to the inversion of configuration at the carbon center. It is characterized by a bimolecular rate law, meaning the rate depends on the concentration of both the nucleophile and the substrate.

Nucleophiles

Nucleophiles are species that donate an electron pair to form a chemical bond in a reaction. In S_N2 reactions, nucleophiles are typically negatively charged or neutral molecules with lone pairs of electrons. In the given reaction, sodium thiolate (S^-) acts as the nucleophile, attacking the electrophilic carbon in bromoethane (CH₃CH₂Br) to form a new bond.

Leaving Groups

Leaving groups are atoms or groups that can depart from the substrate during a chemical reaction, taking with them the electrons from the bond they formed with the substrate. A good leaving group is typically stable after departure and can be a halide ion (like Br^- in this case). The ability of a leaving group to leave easily is crucial for the success of S_N2 reactions, as it influences the reaction rate and product formation.