Question

How to determine the strength of neuclophiles and electrophiles in a reaction mechanism.

Answer 1

Nucleophile
Charge: Nucleophilicity increases with increasing electron density (more negative charge)
Electronegativity: Nucleophilicity decreases as electronegativity increases because these atoms are less likely to share electron density
Steric hindrance: Bulkier molecules are less nucleophilic
· Solvent: Protic solvents can inhibit nucleophilicity by protonating the nucleophile or hydrogen bonding

ELECTROPHILE
greater degree of positive charge increases electrophilicity, so a carbocation is more electrophilic than a carbonyl carbon. Additionally, the nature of the leaving group influences electrophilicity in species without empty orbitals; better leaving groups make it more likely that a reaction will happen.