Categorize The Following Species As A Strong Or Weak Nucleophile, A ND As A Strong Or Weak Base. 0 NaoH NH CHa0H NaCN IPrOH NaOEt NaNH2 PhNH2 0 L- TBuOK NaSH PhS. H2O CHOH PhS. CH3CH2OH CHİ Strong Nu: Strong Base Weak Nu: Weak Base Summarize Why You Know About Each Of The Following Mechanisms. (Circle All That Apply) SN2 SN1 E2 E1 Bi/Uni Bi/Unimolecular
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I wasn’t able to access the link you provided, but I can still help you categorize the nucleophiles and bases. Let me give you a general explanation about them.
Strong vs Weak Nucleophiles and Bases
Strong Nucleophiles:
- NaCN (Sodium Cyanide): Strong nucleophile due to the negative charge on the cyanide ion (CN⁻), which is highly reactive and can easily donate electrons to form a bond with a carbon.
- NaNH₂ (Sodium Ammonia): Strong nucleophile, as NH₂⁻ (amide ion) is highly reactive and can readily attack electrophiles.
- NaOEt (Sodium Ethoxide): Strong nucleophile, because ethoxide (EtO⁻) has a negatively charged oxygen atom, making it ready to donate electrons.
- NaSH (Sodium Hydrosulfide): Strong nucleophile as SH⁻ is negatively charged and can easily donate its lone pair of electrons.
- NaOH (Sodium Hydroxide): Strong nucleophile due to the hydroxide ion (OH⁻) having a lone pair of electrons available for donation.
- I⁻ (Iodide): Iodide is a weak base but a very good nucleophile due to its large size and polarizability.
Weak Nucleophiles:
- H₂O (Water): Water is a weak nucleophile because it has a lone pair of electrons but is stabilized by hydrogen bonding.
- CH₃CH₂OH (Ethanol): Ethanol is a weak nucleophile since its oxygen atom is less available for electron donation than a stronger nucleophile like NaOEt.
- PhNH₂ (Aniline): Slightly weaker nucleophile compared to alkoxide or amide ions but can still donate electrons due to the lone pair on nitrogen.
- PhS (Phenyl Sulfide): Weak nucleophile because it’s part of a conjugated system and the electron density is spread over the phenyl ring, making it less available for nucleophilic attack.
Strong Bases:
- NaNH₂: Strong base because NH₂⁻ is a very powerful proton acceptor.
- TBuOK (Potassium tert-butoxide): Strong base due to the highly negative charge on the oxygen atom and the steric hindrance from the bulky tert-butyl group.
- NaOEt: Strong base, as ethoxide (EtO⁻) can readily deprotonate substrates.
Weak Bases:
- H₂O: Water is a weak base as the oxygen has a neutral charge and is unlikely to deprotonate other molecules.
- CH₃CH₂OH (Ethanol): Ethanol is also a weak base for the same reasons as water.
Mechanisms
- SN2: A bimolecular nucleophilic substitution mechanism, where the nucleophile and the electrophile simultaneously participate in the rate-determining step. This mechanism favors strong nucleophiles and polar aprotic solvents.
- SN1: A unimolecular nucleophilic substitution mechanism, where the rate-determining step involves the dissociation of the leaving group, forming a carbocation intermediate. This mechanism favors weak nucleophiles and polar protic solvents.
- E2: A bimolecular elimination mechanism, where a strong base abstracts a proton from the β-carbon of a substrate, resulting in the formation of a double bond. This mechanism requires a strong base and often occurs simultaneously with an SN2 reaction.
- E1: A unimolecular elimination mechanism, where the rate-determining step is the loss of a leaving group to form a carbocation, followed by deprotonation to form a double bond. This occurs in the presence of weak bases or under conditions favoring carbocation formation.
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