1. Ch. 23 Functional Groups

2. 23.1 Introduction to Functional Groups
Most organic chemistry involves substituents that contain oxygen, nitrogen, sulfur, and/or phosphorus
Functional Groups
chemically functional part of the molecule
a specific arrangement of atoms in a compound that is capable of characteristic chemical reactions

4. Halocarbons
Contains at least one fluorine (F), chlorine (Cl), bromine (Br), or iodine (I) atom
Naming based on IUPAC rules for the name of the parent hydrocarbon

6. Substitution Reactions
One atom or group of atoms replaces another atom or group of atoms
Important method for introducing a new functional group to an organic molecule
Ex. In general for a halogen substitution (halogenation) reaction
Ex. Reaction of methane with chlorine

7. Substitution Reactions
Halocarbons can be used to prepare alcohols
Fluorine is more difficult to displace (generally not used for this purpose)

8. 23.2 Alcohols, Ethers, and Amines
Alcohols: organic compounds with an –OH group (hydroxyl group)
IUPAC naming: drop the –e ending from the parent hydrocarbon and add –ol
Specify which C the –OH group is on with a number before the name
If multiple –OH groups, add number prefix to the –ol ending (ex. Butanol, butanediol, butanetriol)

10. Properties of Alcohols
Capable of hydrogen bonding (intermolecular)
Somewhat soluble in water
Up to 4C alcohols are completely soluble in water
Longer hydrocarbon chains are not soluble because they are mostly nonpolar

11. Uses of Alcohols 2-propanol 1,2,3-propanetriol 1,2-ethanediol Ethanol
Antiseptic
Base for perfumes, creams, lotions, other cosmetics
1,2,3-propanetriol
Absorbs water from surroundings, used as a moistening agent in cosmetics, food, and pharmaceuticals
1,2-ethanediol
antifreeze
Ethanol
Industrial uses (methanol added to “denature”)

12. Fermentation Production of ethanol from sugars by yeast or bacteria
Used to produce ethanol for alcoholic beverages *depressant, fatal in large doses

13. Addition Reactions A substance is added at a double or triple bond
Important method for introducing a new functional group to an organic molecule
Convert alkenes to alkanes

14. Hydration Reactions Water is added to an alkene (H + OH)
Forms an alcohol
Occurs under heat (100⁰C)

15. Halogenation Reactions
Adds 1 or 2 halogens to an alkene or alkyne
Ex. Bromine has an orange color, but most unsaturated compounds form colorless halogenated compounds, so bromine is used to test whether a substance is saturated or not

16. Hydrogenation Reactions

17. Ethers General formula: ROR
Naming: identify the two R groups (hydrocarbons), put in alphabetical order, and add ether to the end

18. Ethers Diethyl ether was the first reliable general anesthetic
Highly flammable and often causes nausea
Diphenyl ether is used in soaps and perfumes (geranium smell)
Boiling points between those of alcohols and hydrocarbons
Less soluble in water than alcohols
fewer hydrogen bonds

19. Amines Contain nitrogen (N) bonded to a carbon group
Similar to ammonia (NH3)
General formulas: RNH2, R2NH, or R3N
IUPAC naming: drop –e ending of parent hydrocarbon and add –amine
Hydrogen bonding is weaker than that of alcohols (N is less electronegative than O)

20. Amines
Used in some dyes such as methyl orange (also used as an indicator)

21. 23.3 Carbonyl Compounds Carbonyl group: general structure C=O
Aldehyde: carbon of the carbonyl group is bonded to at least one hydrogen
Ketone: carbon of the carbonyl group is attached to two other carbons

22. Aldehydes
IUPAC naming: identify and name the longest carbon chain that includes the carbonyl group (C=O), replace the –e ending of the parent hydrocarbon with –al
Most commonly used: methanal (formaldehyde)
making synthetic resins
Preserving biological specimens
Aromatic aldehydes produce scents/flavors ex. almond, vanilla, cinnamon

24. Ketones
IUPAC naming: identify and name the longest carbon chain that includes the carbonyl group, change –e ending to –one, designate the carbonyl carbon with the lowest possible number
Most commonly used: propanone (acetone)
Solvent for resins, plastics, varnishes
Nail-polish remover

26. Properties of Aldehydes and Ketones
No hydrogen bonding between aldehyde or ketone molecules (but weak H-bonds with water)
Weak polar attractions between carbonyl groups
Soluble in non-polar solvents
Smaller compounds are soluble in water

27. Carboxylic Acids
Carboxyl group: carbonyl group bonded to a hydroxyl group (-COOH)
Carboxylic acid: organic compound with a carboxyl group
General formula: RCOOH
Weak acid (see below)
IUPAC naming: replace –e of parent hydrocarbon with –oic acid
Parent hydrocarbon number includes the carbon of the carboxyl group

29. Carboxylic Acids Abundant in nature
Citric acid = 2-hydroxypropane-1,2,3-tricarboxylic acid
Vinegar = acetic acid (acetum is Latin for vinegar)
Fatty acids: first isolated from fats

30. Esters
Contain a carbonyl group and an ether link to the carbonyl carbon
General formula: RCOOR
Contribute characteristic odors to many fruits and perfumes
Neutral substances, cannot form H-bonds with other esters
Can be prepared from a carboxylic acid and an alcohol

31. Esters heated in water do very little, but in presence of acid or base the ester breaks down rapidly

32. 23.4 Polymers
Polymer: a large molecule of repeating smaller molecules covalently bonded together
Monomer: smaller molecules that join to form a polymer

33. Addition Polymers
Form when unsaturated monomers react to form a polymer
Require monomers with double bonds
Often requires a catalyst to get the reaction started
Length of carbon chains can change properties

35. Addition Polymer Examples
Polypropylene: stiffer plastic used for utensils and drink containers
Polystyrene: good insulator

36. Addition Polymer Examples
Polyvinyl chloride (PVC): pipes to upholstery covering
Polytetrafluoroethene (PTFE): heat and corrosion resistant, nonstick, aka Teflon
Polyisoprene: rubber

37. Condensation Polymers
Formed by the joining of monomers with the loss of a small molecule such as water
Polyesters: monomers of dicarboxylic acids and dihydroxy alcohols joined by ester bonds
Must have two functional groups on each monomer

38. Condensation Polymer Examples
Polyamides: carboxylic acid and an amine
Kevlar: bullet-proof vests

39. Condensation Polymer Examples
Nylon: fishing line, hosiery, zippers

40. Condensation Polymer Examples
Nomex: flame-resistant clothing and electrical fixtures
Proteins