6.7 Kinetics of a nucleophilic substitution reaction An s2 reaction CH3—c!+:OH CH3-OH CI(SN N2 reaction) HO Table 6.3 Rate study of reaction of CH3 CI with oh at 60 No initial [CH3Cl] initial [OH initial rate(mol L-Is- 0.0010 4.9X107 234 0.0020 98X107 0.0010 9.8ⅹ107 0.0020 2.0 19.6ⅹ107 Rate a CH3Cl] [OH] Rate =k I CH3Cl] JOHI Second order reaction(二级反应)---(SN2 reaction)
6.7 Kinetics of a nucleophilic substitution reaction: An SN2 reaction Table 6.3 Rate study of reaction of CH3 Cl with OH at 60 - o No initial [CH3 Cl] initial [OH- ] initial rate (mol L -1 s -1 ) 1 0.0010 1.0 4.9 X 10 -7 2 0.0020 1.0 9.8 X 10 -7 3 0.0010 2.0 9.8 X 10 -7 4 0.0020 2.0 19.6 X 10 -7 CH3 Cl + :OH CH3 OH + Cl - - 60 o H2 O (SN2 reaction) Rate [ CH3 Cl] [OH - ] Rate [ CH3 Cl] [OH - k ] Second order reaction(二 级 反 应 ） ---- (SN2 reaction)
6. 8 a mechanism for the su2 reaction (S2的反应机理) Transition state(过渡态) NuC forms at the same time L-c breaks 2. Inversion of configuration构形翻转)
6.8 A mechanism for the SN2 reaction （SN2的反应机理） N + L Nu C Transition state （过 渡 态 ） + : L Nu--C forms L--- C breaks 1. at the same time 2. Inversion of configuration (构 形 翻 转 ）
S2 Reaction H HO Hy}-c-HO……→-cl|-o H+ c H transition state Generally speaking; Primary alkyl halides is a sn2 reaction R—cH2X 伯卤代烃一般按S历程进行
SN2 Reaction H Cl H H HOH H H HO Cl - - HO H H H transition state + Cl - Generally speaking; Primary alkyl halides is a SN2 reaction X R CH2 X 伯卤代烃一般按SN2历程进行
6.9 Transition state theory: Free energy diagrams(SN2) HO c—XHO cl→H IIlIH HH transition state HO----CH3 E △G Ho +CHCI △G=△H-T△S △ CH3OH+Cr Reaction coordinate(反应进程)
6.9 Transition state theory: Freeenergy diagrams (SN2) H Cl H H HO- HO Cl - - HO H H H transition state + Cl - HO- + CH3Cl CH3OH + Cl - G o G HO CH3 Cl E Reaction coordinate（ 反 应 进 程 ） - - G = H - T S H H H
Fig 6.6 A potential energy diagram for the reaction of methyl chloride with hydroxide ion at 60oC H0----CH AG less than 20 kcal mol, it will take place readily at room temp, if it is greater △G HO CH3CI 245 than 20 kcal mol. heating will be requir △G° 24 kcal mol CHOH +Cl Reaction coordinate(反应进程)
Fig 6.6 A potential energy diagram for the reaction of methyl chloride with hydroxide ion at 60 oC HO- + CH3 Cl CH3 OH + Cl - G o G HO CH3 Cl E Reaction coordinate（ 反 应 进 程 ） - - 24.5 -24 kcal mol -1 # G # less than 20 kcal mol -1 , it will take place readily at room temp, if it is greater than 20 kcal mol -1 , heating will be required