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Figure 4.9 Stabilization of carbocations via the inductive effect

Figure 4.9 Stabilization of carbocations via the inductive effect. Electronic effects transmitted through  bonds are called "inductive effects.". electrons in C—C bonds are more polarizable than those in C—H bonds; therefore, alkyl groups stabilize carbocations better than H. . .

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Figure 4.9 Stabilization of carbocations via the inductive effect

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  1. Figure 4.9 Stabilization of carbocationsvia the inductive effect Electronic effects transmitted through bonds are called "inductive effects." electrons in C—Cbonds are more polarizable than thosein C—H bonds; therefore, alkyl groupsstabilize carbocationsbetter than H.    

  2. Figure 4.10 Stabilization of carbocationsvia hyperconjugation electrons in this bond can be sharedby positively chargedcarbon because thes orbital can overlap with the empty 2porbital of positivelycharged carbon +

  3. Figure 4.10 Stabilization of carbocationsvia hyperconjugation electrons in this bond can be sharedby positively chargedcarbon because thes orbital can overlap with the empty 2porbital of positivelycharged carbon  

  4. Figure 4.10 Stabilization of carbocationsvia hyperconjugation Notice that an occupiedorbital of this type isavailable when sp3hybridized carbon is attached to C+, but is not availabe when His attached to C+. Therefore,alkyl groupsstabilize carbocationsbetter than H does.  

  5. + R R C R Carbocations The more stable a carbocation is, the faster it isformed. Reactions involving tertiary carbocations occurat faster rates than those proceeding via secondarycarbocations. Reactions involving primary carbocations or CH3+ are rare.

  6. + R R C R Carbocations Carbocations are Lewis acids (electron-pairacceptors). Carbocations are electrophiles (electron-seekers). Lewis bases (electron-pair donors) exhibit just theopposite behavior. Lewis bases are nucleophiles(nucleus-seekers).

  7. .. – : : Cl .. .. : Cl (CH3)3C .. Mechanism Step 3: Capture of tert-butyl cation by chloride ion. + + (CH3)3C fast, bimolecular tert-Butyl chloride

  8. .. .. – : Cl : : Cl (CH3)3C .. .. Carbocations + The last step in the mechanism of the reaction oftert-butyl alcohol with hydrogen chloride is the reaction between an electrophile and a nucleophile. tert-Butyl cation is the electrophile. Chloride ionis the nucleophile. + (CH3)3C

  9. + – Fig. 4.11 Combination of tert-butyl cation andchloride ion to give tert-butyl chloride nucleophile (Lewis base) electrophile (Lewis acid)

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