1. Organic Chemistry 4 th Edition Paula Yurkanis Bruice Chapter 3 Alkenes: Structures, Nomenclature, and an Introduction to Reactivity Thermodynamics and Kinetics Irene Lee Case Western Reserve University Cleveland, OH ©2004, Prentice Hall

2. Hydrocarbons containing double bonds Alkenes

3. Noncyclic alkene: C n H 2n Cyclic alkene: C n H 2n–2 Molecular Formula of Alkene

4. Systematic Nomenclature of Alkenes Longest continuous chain containing the functional group

5. Cite the substituents in alphabetical order Name with the lowest functional group number and then the lowest substituent numbers

6. No numbering of the functional group is needed in a cyclic alkene

7. Special Nomenclatures

8. Structure of Alkene

9. Isomers of Alkene

10. Dipole Moments of Alkene Isomers

11. Conversion of alkene isomers requires breaking of the  bond between the two sp 2 carbons

12. Cis-Trans Interconversion in Vision

13. E and Z isomers

14. Naming by the E,Z System Rule 1: Consider the atomic number of the atoms bonded directly to a specific sp 2 carbon.

15. Rule 2: If there is a tie, consider the atoms attached to the tie.

16. Rule 3: Multiple bonds are treated as attachment of multiple single bonds.

17. Rule 4: Rank the priorities by mass number in isotopes.

18. An alkene is an electron-rich molecule Nucleophile: an electron-rich atom or molecule that shares electrons with electrophiles Examples of Nucleophiles A nucleophile

19. Nucleophiles are attracted to electron-deficient atoms or molecules (electrophiles) Examples of Electrophiles

20. Electrophilic Addition of HBr to Alkene

21. Curved Arrows in Reaction Mechanisms Movement of a pair of electrons Movement of one electron

22. Utilization of Curved Arrows

23. Rules for Use of Curved Arrows

25. A Reaction Coordinate Diagram Transition states have partially formed bonds Intermediates have fully formed bonds

26. Thermodynamics describes the properties of a system at equilibrium

27. Thermodynamic Parameters Gibbs standard free energy change (  G ° ) Enthalpy (  H ° ): the heat given off or absorbed during a reaction Entropy (  S ° ): a measure of freedom of motion  G ° =  H ° – T  S ° If  S ° is small compared to  H °,  G ° ~  H °

28. Exergonic Reaction –G°–G° Endergonic Reaction +G°+G°

29.  H ° can be calculated from bond dissociation energies

30. Solvation: the interaction between a solvent and a molecule (or ion) in solution Solvation can affect  H ° and/or  S °, which ultimately affects  G °

31. Kinetics deals with the rate of chemical reactions and the factors that affect those rates The rate-limiting step controls the overall rate of the reaction Rate of a reaction = number of collisions per unit time fraction with sufficient energy fraction with proper orientation xx

32. The free energy between the transition state and the reactants

33.  G ‡ : (free energy of transition state) – (free energy of reactants)  G ‡ =  H ‡ – T  S ‡  H ‡ : (enthalpy of transition state) – (enthalpy of reactants)  S ‡ : (entropy of transition state) – (entropy of reactants)

34. Rates and Rate Constants First-order reaction AB rate = k[A] Second-order reaction A + B C + D rate = k[A][B]

35. The Arrhenius Equation k = Ae –E a /RT E a =  H ‡ + RT Rate Constants and the Equilibrium Constant k1k1 k –1 K eq = k 1 /k –1 = [B]/[A]

36. Transition State versus Intermediate Transition states have partially formed bonds Intermediates have fully formed bonds intermediate

37. Electrophilic Addition of HBr to 2-Butene The rate-limiting step controls the overall rate of the reaction