CHEM 2OA3 Lecture Notes - Solvent Effects, Leaving Group, Electronegativity

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Inversion does not necessarily mean r s. What makes a good l- (a-): ability to accommodate e-pair (charge): e-negativity + resonance, size of the orbital describing the e-pair, indirectly: bond strength c-l (h-a) Iodine is the best leaving group and nucleophile (in the halides: increasing size is more important to good leaving group than increasing electronegativity. Affected by charge, basicity, solvent, polarizability, sterics: charge (for same atom) The more charged, the more nucleophilic: basicity (decreases to the right in pt, so does nu) Nucleophilicity doesn"t always track with basicity (basicity decreases as you go down the. Pt, but nucleophilicity increases: reason: solvent effects and polarizability (deformability of orbitals) have a strong influence. Protic solvent: solvents with hydrogen attached to electronegative atom (e. g. oxygen: polar ; h2o, roh, r2nh. Solvent shell increases size of the nucleophile, so nucleophilicity increases (going down pt: this stuff is always true in protic solvent, but not.