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Published byBethany Wilson Modified over 9 years ago
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Carbocationic Reaction Intermediates: Factors that influence carbocation formation Nature of the leaving group Structural factors Solvent effects Salt effects Isotope effects
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Factors that influence carbocation formation Nature of the leaving group
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Factors that influence carbocation formation Anionic leaving groups
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Factors that influence carbocation formation Structural factors
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Factors that influence carbocation formation Solvent effects Solvent effects : Any property of a solvent system that can lower the energy of activation for heterolytic bond cleavage will favor carbocation formation.
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The role of solvent in carbocation formation Dielectric constant - a rough measure of the ability of the solvent to separate oppositely charged ions. Dielectric constant - a rough measure of the ability of the solvent to separate oppositely charged ions. Hydrogen-bonding ability Hydrogen-bonding ability Acid-base properties Acid-base properties Nucleophilicity: As the nucleophilicity of a solvent decreases, the likelihood of discrete carbocation formation increases. Nucleophilicity: As the nucleophilicity of a solvent decreases, the likelihood of discrete carbocation formation increases.
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Salt Effects: Ionic Strength As the ionic concentration of a solvent system increases, the overall polarity of the medium increases. Increased solvent polarity favors ionization of neutral molecules.
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Common Ion (Mass Law) Effect
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Special Salt Effect
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Factors that influence carbocation formation Isotope effects
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Nature of some carbocationic intermediates Stability of the intermediate
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Stereochemistry of Carbocations
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Stereochemistry of carbocations
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Kinetics of carbocation formation
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