1. Organic Chemistry

2. Organic Chemistry: Carbon Compound Chemistry Organic chemistry is the chemistry of carbon compounds. Originally these were compounds that were studied from organisms.

3. An Early Perspective on Organic Chemicals In Organic chemistry’s early stages, chemists wondered if chemicals from living things had some special properties or life force associated with them. The compound, urea, was isolated from human urine. To show it was just a regular chemical without special life properties, Wohler (a German chemist) made urea from scratch in a chemical laboratory.

4. Hydrocarbons Hydrocarbons are compounds of just carbon and hydrogen.

5. Hydrocarbons Many hydrocarbons are produced by fractional distillation of crude oil.

6. Alkanes: Single Bonds Hydrocarbons with only single bonds between all carbon atoms are called alkanes.

7. Alkanes: General Formula The general formula for alkanes is C n H 2n+2.

8. Bond Number in Hydrocarbons In any organic compound, every C atoms always has 4 bonds, every H atom always has 1 bond, every O atom always has 2 bonds, every halogen atom (F, Cl, Br, I) always has 1 bond and every N atom always has 3 bonds.

9. Alkane Nomenclature

10. Alkane Boiling Points As the hydrocarbon chains gets longer, the boiling points increase due to increasing London forces between the increasingly longer molecules.

11. Branched Alkanes Alkanes can have many branches coming off a main chain.

12. Side Chain Groups If a hydrogen atom is detached from an alkane chain, it becomes a group that can be attached to another alkane chain. A methyl group is a methane minus a hydrogen atom. An ethyl group is an ethane minus a hydrogen atom.

13. Alkane Nomenclature 1.Number the longest carbon chain so that side groups get the lowest numbers. 2.Use numbers followed by commas and dashes to indicate group locations and names. Below is 3,3,6-trimethylheptane :

14. Alkane Nomenclature 1.Number the longest carbon chain so that side groups get the lowest numbers. 2.Use numbers followed by commas and dashes to indicate group locations and names. The left structure is 1,3-dichlorohexane The right structure is 2,3-dichloropentane

15. Alkane Nomenclature 1.Number the longest carbon chain so that side groups get the lowest numbers. 2.Use numbers followed by commas and dashes to indicate group locations and names. The side groups are listed alphabetically: ethyl before propyl. Below is 3-ethyl-4,5-dipropyloctane.

16. Alkane Nomenclature 1.Number the longest carbon chain so that side groups get the lowest numbers. 2.Use numbers followed by commas and dashes to indicate group locations and names (alphabetic order). Below is 4,6-diethyl-4,6,7-trimethyl-5,5-dipropyldecane Not 5,7-diethyl-4,5,7-trimethyl-6,6-dipropyldecane

17. Isomers Isomers are organic compounds which have the same chemical formula but have different structures and properties. The isomers of C 5 H 12 are shown

18. Isomers Isomers are organic compounds which have the same chemical formula but have different structures and properties. The isomers of C 6 H 14 are shown

19. Cycloalkanes Alkane rings are called cycloalkanes. Their general formula is C n H 2n.

20. Cycloalkanes Cycloalkanes can have groups and are numbered so that the groups get the lowest numbers as with alkane chains.

21. Alkenes Alkenes are hydrocarbons with one or more double bonds. Alkenes are named by the numbers of carbon atoms like alkanes but with an “ene” ending. The last three structures to the right shown require an extra H at the rt. End of the molecule. Alkenes have a general formula, C n H 2n.

22. Alkene Nomenclature Some alkenes can have their double bonds in numerous positions so their naming system accounts for the double bond placement.

23. The Geometry of Alkenes Unlike alkanes in which atoms can freely rotate, in alkenes the double bond rigidly fixes atoms on either side of the double bond.

24. Cis-Trans Isomers In alkenes with groups other than hydrogen, two different molecules are possible with the same formulas. Trans isomers have the groups diagonally opposite while cis isomers have the groups on the same side of a molecular axis.

25. Cis and Trans 2-Pentene The groups on opposite sides of the double bond in 2- pentene are in different positions so these molecules are isomers

26. Alkene Nomenclature Some alkenes can have their double bonds in numerous positions so their naming system accounts for the double bond placement. But-1-ene can be called n-butene or 1- butene.

27. Alkynes Alkynes have one or more triple bonds. They are named by using the standard alkane root and applying a “yne” ending rather than the “ane” ending.

28. Triple Bond Position Alters an Alkyne’s Name Like alkenes, alkynes need to have their triple bond position notated in their name.

29. General Formula for an Alkyne The general formula for an alkyne is C n H 2n-2.

30. The Geometry of Alkynes The triple bond of an alkyne is very rigid. Parts of alkynes with repeating triple bonds form straight, needle-like molecules.

31. Comparison of Single, Double and Triple Bonds The length of a bond shortens from single to double to triple bonds.

32. Benzene – A Ring Compound Benzene, C 6 H 6, is a common organic molecule.

33. Benzene’s Bond Lengths Although benzene can be constructed with alternating double and single bonds, every bond between the carbons is midway between a single and a double bond.

34. Explaining Benzene’s Intermediate Bond Length A concept called resonance is used to explain the intermediate bond length of benzene’s bonds. Resonance is the idea that the double bonds alternate between the atoms which evens out the sharing of electrons, bonds of intermediate length.

35. Resonance in Benzene Different resonance structures show alternating double bonds.

36. Ways of Representing Benzene

37. Aromatic Compounds Any compound incorporating the benzene ring is called an aromatic compound.

38. Many Aromatic Compounds have Aromas Spearmint smell

39. Steroid Molecules are Aromatics

40. Functional Groups A functional group is a specific group of atoms on a molecule that gives it specific properties.

41. Alcohols All alcohols have one or more hydroxyl groups (-OH) The General Form of an alcohol is R-OH, where R stands for any organic chain or ring.

42. Naming Alcohols The molecule above is 3-methyl-2-pentanol Alcohols take the longest chain name, replacing the regular ending with an –ol ending.

43. Properties of Alcohols Alcohols have an –OH group (polar character) that makes them more soluble in water but they may also have longer hydrocarbon chains (nonpolar character) which make them less soluble in water.

44. Review of Polar Molecules Water is a polar molecule (develops + and – poles) because the oxygen atom attracts shared electrons more than hydrogen does.

45. Polar Water Molecules Attract Polar Substances Water, a polar substance will dissolve other polar substances or substances with charged particles.

46. The “Like Dissolves Like” Rule Nonpolar substances (like gasoline) dissolve and mix with (are soluble in) nonpolar substances while polar substances are soluble with polar substances.

47. Polar and Nonpolar Substances are Immiscible (Do Not Mix)

48. Properties of Alcohols If the –OH group is more prominent than the carbon chain, the alcohol is soluble (methanol, ethanol and propanol). If the chain is more prominent, the alcohol resists dissolving in water (butanol, pentanol etc.)

49. Other Alcohol Properties All alcohols are poisonous Ethanol (in beer, wine and spirits) is less poisonous but slows down the nervous system and shut down the brain and breathing. When drunk persons pass out, they may stop breathing. The liver detoxifies ethanol.

50. The Aldehyde and Ketone Functional Group The carbonyl group converts an organic compound into either an aldehyde or a ketone, depending on whether the group is on an end carbon or a carbon within a chain.

51. A Carbonyl Group on an End Carbon, makes an Aldehyde An aldehyde changes the root name to –al. Methanal (commonly called formaldehyde), ethanal, and propanal are three aldehydes.

52. An Aromatic Aldehyde Benzylaldehyde is formed from benzene and an attached carbon with carbonyl group.

53. Ketones Made by Internal Carbonyl Ketones have a carbonyl group on a carbon not on the end of a molecule. Ketones change the regular chain ending to -one

54. Naming Ketones Besides changing the ending to –one, the position of the carbonyl group must be indicated. 3-pentanone

55. The Organic Acid Group Carboxyl groups (-COOH) attached to an organic molecule give the molecule an acidic character.

56. Naming Organic Acids Organic Acids change the root name ending to –oic acid. (methanoic, ethanoic, propanoic acids)

57. Methanoic Acid (Formic Acid) Ants use formic acid as a defense or stunning chemical against predators or prey.

58. Ethanoic Acid (Acetic Acid) The active ingredient of vinegar is acetic acid, usually present in about 5% by volume. Vinegar is often manufactured from ethyl alcohol in wines or ciders.

59. Other Organic Acids with COOH Group(s)

60. The Ether Linkage The oxy group makes ethers of organic compounds.

61. Naming Ethers The shortest hydrocarbon chain prefix is used with oxy followed by the longer chain hydrocarbon name unchanged. Methoxypropane

62. Branched Chain Ethers When naming branched chained ethers, the carbons on the chains are numbered from the oxy group. The formula for 1-methoxy-3,3-dimethylbutane is CH 3 OCH 2 CH 2 C(CH 3 CH 3 )CH 3

63. Properties of Ethers Ethers have low boiling points, evaporating readily. Ethers have anaesthetic properties, rendering higher organisms unconscious, “quieting” lower organisms.

64. The NH 2 Group and Amines An amine is an organic compound containing an NH 2 group. Amines often have “fish-like” odour.

65. Amino Acids Amino acids have an amine group and an acid group.

66. Amino Acids Living things make and use amino acids. There are 20 naturally- occuring amino acids. A

67. Amino Acids Amino acids link together to form long chains that become proteins, very important compounds in living things.

68. Bonding of Amino Acid When amino acids are bonded together, they lose a water molecule, so this type of reaction is called a condensation synthesis

69. Amino Acids The bond between amino acids is called a peptide bond and a chain of amino acids is called a polypeptide

70. Amino Acid Bonding The linkage between amino acids (peptide bond) is generally known as an amide linkage The oxygen in the above structure should have a double bond !

71. Amides Amides have the amide group, CONH 2 Amide chains are numbered from the amide group A

72. The Ester An ester is an organic compound in which a COO group joins two hydrocarbon chains.

73. The Ester Esters often have distinct aromas and flavours.

74. Alcohols and Acids React, Forming Esters In naming an ester, the alcohol chain is given a –yl ending followed by the acid chain name whose ending becomes – ate.

75. Examples of Esters Rum is isobutyl propionatePear is propyl formate Apple is methyl butyrateOrange is octyl acetate Banana is 3-methyl butylacetate

76. Triglycerides (Fats) and the Ester Linkage Fatty acids are linked to glycerol by means of ester linkages.

77. Summary of Functional Groups Groups not represented include esters and ethers A

78. Summary of Functional Groups

79. Organic Reactions: Oxidation and Reduction Organic molecules are oxidized if they have oxygen added to the molecule or if they have hydrogen removed from the molecule Alcohol in wine is oxidized to ethanal and then to acetic acid (Wine in air or acted on by aerobic bacteria turns to vinegar).

80. Substitution Reactions Substitution reactions occur with alkanes. One atom or group on a chain is substituted with another. + Cl-Cl  + H-Cl

81. Multiple Substitutions When chlorine gas is reacted with methane, Cl atoms can substitute up to four hydrogens. + Cl-Cl  + H-Cl chloroform

82. Displacement Reactions One group can take the place of another and this is called a displacement reaction. + NH 3  + H-Cl

83. Addition Reactions In alkenes, a double bond can be opened, leaving two sites for the parts of another substance to bond to. Alkenes are more reactive than alkanes. + H-O-H 

84. Examples of Other Addition Reactions

85. Polymerization Reaction (Forming Plastics) A monomer is a repeating unit found within a larger molecule. A polymer is a molecule made up of similar repeating monomers. Polymerization is the reaction in which monomer link together to form polymers.

86. Addition Polymerization Reactions Addition polymerization involves the bonding of polymers without the elimination of atoms. Molecules with double bonds open one of the bonds which allows them to link together in a long chain. The monomer ethene opens one of its double bonds to form a long polymer, polyethylene. + 

87. Addition Polymerization Reactions Addition polymerization involves the bonding of polymers without the elimination of atoms. Molecules with double bonds open one of the bonds which allows them to link together in a long chain. The monomer ethene opens one of its double bonds to form a long polymer, polyethylene.

88. Teflon Addition Polymer Teflon is a plastic (polymer) used for valves and non-stick surfaces.

89. Saran Addition Polymer

90. Lucite Addition Polymer

91. Plexiglass Addition Polymer A

92. PVC Addition Polymer A

93. Styrofoam Addition Polymer A

94. Condensation Polymerization Reactions Condensation polymerization results in the elimination of atoms, often water molecules.

95. Protein

96. Dacron (A Polyester) :Condensation Polmerization

97. Elastomers A

98. Thermoplastic Plastics A

99. Thermosetting Plastics A

100. A A

101. A A