Chapter 12

1. Chapter 12 Organic Chemistry: Fuels and Materials

2. Peak Oil??? M. King Hubbert predicted the US production would peak in 1970…and he was right!

3. Clausius-Clapeyron Equation Pine Oil The smell of fresh cut pine is due in part to the cyclic alkene pinene, whose structure is shown in Figure P12.47. Use the data in the table to calculate the heat of vaporization, ΔHvap, of pinene.

4. Problem 12.47

5. Clausius-Clapeyron Equation ln(Pvap) = -DHvap/R (1/T) + C This equation suggests that if the vapor pressure is known that the enthalpy of vaporization (DHvap)can be calculated. This equation generally holds true for small values of DT as DHvap values typically change with temperature.

8. Petroleum Refineries use hydrocarbon volatility to separate marketable fractions of crude oil. The more volatile fractions have a greater vapor pressure. Raoult’s Law Ptotal = SciP°I

9. DNA (deoxyribonucleic acid) is the blueprint for all cellular structure and function. All functions of DNA depend on interactions with proteins. Thus the importance of understanding and modeling these interactions can not be understated.

10. Organic Chemistry • Organic chemistry is the study of the compounds of carbon, in which carbon atoms are bound to other carbon atoms, to hydrogen atoms, and to atoms of other elements (esp. N, O, S, P). • Organic chemistry spans many diverse fields from drug discovery, material sciences, biology and the origins of live.

11. Organic Chemistry • Polymers or macromolecules are very large molecules with high molar masses (e.g. latex, nylon or DNA and proteins) • Oligomers are molecules that contain a few monomers; this is the middle ground between small molecules and polymers. • Monomers are small molecules that bond together to form polymers.

12. Alkane R-H Aldehyde Alkene Ketone Alkyne Carboxylic Acid Aromatic Ester Alcohol R-OH Amide Ether R-O-R Amine RNH2, R2NH, R3N Common Orgainic Functional Groups

13. Hydrocarbons • Alkanes are hydrocarbons in which all the bonds are single bonds. • Alkenes are hydrocarbons containing one or more carbon-carbon double bonds. • Alkynes are hydrocarbons containing one or more carbon-carbon triple bonds.

14. Alkanes are saturated hydrocarbons common in gasoline and oils. n-alkanes are straight chains, i.e. each carbon atom is bound to no more than two other carbon atoms. They have the general formula: CH3(CH2)nCH3 Or CnH2n+2 Cycloalkanes are formulated “cuts” of crude oil and are commonly C5 – C12, but have the formula: CnH2n.

15. DHf= -167kJ/mole Hexane Conformations of Cyclohexane DHf= -123 kJ/mole DE= 33 kJ/mole

16. Melting Points and Boiling points for n-alkanes

18. Melting Points of n-alkanes

19. Alkanes having more than three carbons can be formulated into branched alkanes. Iso-octane is used to rate gasoline for combustion or “anti-knock” properties.

20. Alkane Isomerism

22. Rules for naming alkanes • H • H H H H H H-C-H H • | | | | ׀ | ׀ • H-C—C—C—C-H H-C —C —C-H • | | | | | | | • H H H H H H H • 1. Locate the longest carbon chain, or backbone, of the molecule.2. Assign a base name that corresponds to the number of carbon atoms in the longest chain. Thus, the name of the isomer of butane in the left-hand structure shown above should rightly be butane because there are four carbon atoms in its backbone. The isomer depicted in the right-hand structure has only a three-carbon backbone, and so it has the base name propane.

23. 3. The name of a linear, or straight-chain, alkane is simply its base name, though the names of these normal alkanes may be preceded by n- Thus, butane is sometimes referred to as n-butane. 4. The name of an isomer with substituents bonded to one or more middle carbon atoms includes the names of the backbone with a prefix that includes: a) the number(s) of the carbon atom(s) to which the substituents are bonded; b) the number of substituents (if there is more than one) of each type using the appropriate prefix – e.g., di for 2, tri for 3, and tetra for 4; to name the substituents. The substituent names are listed alphabetically. And numbering is done to keep the numbers as low as possible.

24. Structural Isomers of Octane

25. Name these structures

26. Problem Draw the Lewis structures of the following. (a) 2-methylpentane(b) 2,3-dimethylhexane(c) 2,3-dimethylbutane(d) 2-methyl-3-ethylpentane

27. Alkenes and Alkynes • Alkenes and alkynes are unsaturated hydrocarbons. • The reaction of an unsaturated hydrocarbon with hydrogen is called hydrogenation.

28. Examples

29. Terms • A homologous series is a set of related organic compounds that differ from one another by the number of subgroups, such as -CH2-, in their molecular structure. • A methylene group (-CH2-) is a structural unit that can make two bonds. • A methyl group (-CH3) is a structural unit that can make only one bond.

30. Structural Isomers

31. n-Alkanes Formula Structural Formula Name CH4 CH4 Methane C2H6 CH3CH3 Ethane C3H8 CH3CH2CH3 Propane C4H10 CH3CH2CH2CH3 Butane C5H12 CH3CH2CH2CH2CH3 Pentane C6H14 CH3CH2CH2CH2CH2CH3 Hexane C7H16 CH3CH2CH2CH2CH2CH2CH3 Heptane C8H18 CH3CH2CH2CH2CH2CH2CH2CH3 Octane C9H20 CH3CH2CH2CH2CH2CH2CH2CH2CH3 Nonane C10H22 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3 Decane

32. Naming Alkanes • Find the longest continuous chain of carbon atoms to assign the parent name. • Find whatever groups that are not apart of the longest continuous chain. Name these as prefixes. • Assign numbers to the groups by counting from one end of the chain. A chain has two end so start with the end closest to the groups. • If there are two or more identical groups, we use prefixes to designate the number. di - 2, tri - 3, tetra - 4, penta - 5, etc. • If there are two or more different groups, we put all of them into the prefix in alphabetical order.

33. Some Common Alkyl Groups

34. Naming Examples

35. Cycloalkanes Carbon atoms in alkanes have tetrahedral geometry, therefore cycloalkanes are not planar structures.

36. Refineries use Fractional Distillation

37. Simple and Fractional Distillation Graph

38. Raoult’s Law & Fractional Distillation • Raoult’s Law • Ptotal = X1P1 + X2P2 ••• • Raoult’s Law applies to ideal solutions • Ideal solutions have similar strengths of solute-solvent, solvent-solvent, and solute-solute intermolecular interactions.

39. Behavior of Nonideal Solutions

40. Alkenes and Alkynes

42. Isomers • Geometric isomers are structures in which molecules with the same connectivity have atoms in different positions because of restricted rotation. • A cis isomer (or Z isomer) has two like groups on the same side of a line drawn through the double bond. • A trans isomer (or E isomer) has two like groups on opposite sides of a line drawn through the double bond.

43. Example

44. Naming Alkenes and Alkynes • The suffix -ene is used when double bonds are present or -yne when triple bonds are present. • When a chain has 4 or more carbons, the chain is numbered for the position of the multiple bond. The position must be the lowest possible value. • The longest chain must include the multiple bond. • Compounds with two or more double bonds are given the suffixes diene, triene, and so on.

45. Practice Name the following compound. CH3CH=CCH2CH3 CH2CH3

46. Polymers of Alkenes n CH2=CH2 ---> -[CH2CH2]-n

47. Other Polymers

48. Aromatic Compounds

49. Structural Isomers of Aromatic Compounds

50. Polymers Containing Aromatic Rings