Ch_322a_6.06

Ch_322a_6.06 - Transition State Theory In the SN2 mechanism...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Transition State Theory In the S N 2 mechanism proposed by Hughes and Ingold, there is only a single step . As the nucleophile begins to bond to the backside of the carbon center, the leaving group is departing the front side. To achieve these bonding changes, the reactants must proceed over an energy barrier called the transition state . HO - + C Cl H H H C Cl HO H H H ! - ! - transition state This state exists only for the duration of a bond vibration, around 10 -12 seconds . HO C H H H + Cl -
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Transition State Theory: Free Energy Diagrams The standard free energy change ( ! G o ) in a chemical reaction may be negative (exergonic, energy released), or positive (endergonic, energy taken on). CH 3 Cl + HO - CH 3 OH + Cl - ! G o = -24 kcal/mol ! H o = -18 kcal/mol Ar 60 o C in water, this reaction is both exergonic and exothermic . Spontaneity of the Reaction Since the standard free energy change is related to the equilibrium constant by ! G o = -2.3RTLog K eq K eq = 5.6 x 10 15 at 60 o C, Such a large value for K
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/22/2009 for the course CHEM 322AL taught by Professor Jung during the Summer '07 term at USC.

Page1 / 6

Ch_322a_6.06 - Transition State Theory In the SN2 mechanism...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online