Aldehydes and Ketones

1. Aldehydes and Ketones • The functional group in aldehydes and ketones is the carbonyl group.

2. Aldehydes and Ketones • Except for formaldehyde, aldehydes have one H atom and one organic group bonded to a carbonyl group. • Ketones have two organic groups bonded to a carbonyl group.

3. Aldehydes and Ketones • Common names for aldehydes are derived from the name of the acid with the same number of C atoms. • IUPAC names are derived from the parent hydrocarbon name by replacing -e with -al.

4. Aldehydes and Ketones • The IUPAC name for a ketone is the characteristic stem for the parent hydrocarbon plus the suffix -one. • A numeric prefix indicates the position of the carbonyl group in a chain or on a ring.

5. Amines • Amines are derivatives of ammonia in which one or more H atoms have been replaced by organic groups (aliphatic or aromatic or a mixture of both). • There are three classes of amines.

6. Carboxylic acids contain the carboxyl functional group. The general formula for carboxylic acids is: R represents an alkyl or an aryl group Carboxylic Acids • IUPAC names for a carboxylic acid are derived from the name of the parent hydrocarbon. • The final -e is dropped from the name of the parent hydrocarbon • The suffix -oic is added followed by the word acid. • Many organic acids are called by their common (trivial) names which are derived from Greek or Latin.

7. Carboxylic Acids

8. Carboxylic Acids • Positions of substituents on carboxylic acid chains are indicated by numeric prefixes as in other compounds • Begin the counting scheme from the carboxyl group carbon atom. • They are also often indicated by lower case Greek letters. •  = 1st C atom •  = 2nd C atom •  = 3rd C atom, etc.

9. Nomenclature of Carboxylic Acids • Dicarboxylic acids contain two carboxyl groups per molecule.

10. Carboxylic Acids • Aromatic acids are usually called by their common names. • Sometimes, they are named as derivatives of benzoic acid which is considered to be the "parent" aromatic acid.

11. Some Derivatives of Carboxylic Acids

12. When compounds contain more than one functional group, the order of precedence determines which groups are named with prefix or suffix forms. The highest precedence group takes the suffix, with all others taking the prefix form. However, double and triple bonds only take suffix form (-en and -yn) and are used with other suffixes.

14. Isomerism • Isomers have identical composition but different structures • Two forms of isomerism • Constitutional (or structural) • Stereoisomerism • Constitutional • Same empirical formula but different atom-to-atom connections • Stereoisomerism • Same atom-to-atom connections but different arrangement in space.

15. Structural Isomers

16. Cis-2-butene Trans-2-butene Stereoisomers: Geometric Geometric isomers can occur when there is a C=C double bond.

17. Stereoisomers: Optical • Optical isomers are molecules with non-superimposable mirror images. • Such molecules are called CHIRAL • Pairs of chiral molecules are enantiomers. • Chiral molecules in solution can rotate the plane of plane polarized light. • Chirality generally occurs when a C atom has 4 different groups attached. Lactic acid

18. Chirality: Handedness in Nature These molecules are non-superimposable mirror images.

19. Sugars: Related to Alcohols • Sugars are carbohydrates, compounds with the formula Cx(H2O)y. What is the difference between a and b D-glucose?

20. Deoxyribose, the sugar in the DNA backbone. Sucrose and Ribose

21. Fats and Oils R = organic group with NO C=C bonds C12 = Lauric acid C16 = Palmitic acid C18 = Stearic acid What is the functional group in a fat or oil? R = organic group with C=C bonds C18 = oleic acid

22. C=C bond Fats and Oils Fats with C=C bonds are usually LIQUDS Oleic acid: a monounsaturated fatty acid

23. C=C bond Trans Fatty Acids • Oleic acid is a mono–unsaturated cis-fatty acid • Trans fatty acids have deleterious health effects. • Trans fatty acids raise plasma LDL cholesterol and lower HDL levels.

24. Alpha-Amino Acids

25. Peptides and Proteins – H2O Adding more peptide links ---> PROTEIN

26. Polymers • Giant molecules made by joining many small molecules called monomers • Average production is 150 kg per person annually in the U.S.

27. Polymer Classifications • Thermoplastics (polyethylene) soften and flow when heated • Thermosetting plastics — soft initially but set to solid when heated. Cannot be resoftened. • Other classification: plastics, fibers, elastomers, coatings, adhesives

28. Polymer Preparation • Addition polymers — directly adding monomer units together • Condensation polymers — combining monomer units and splitting out a small water (water)

29. Linear, high density PE (HDPE) Types of Polyethylene Branched, low density PE, LDPE Cross-linked PE, CLPE

30. Types of Polyethylene Table 11.12: others are PVC, acrylonitrile, polypropylene, polymethyl methacrylate

31. Bubble Gum!A copolymer Styrene + butadiene

32. Condensation Polymers

33. Polyamides: Nylon • Each monomer has 6 C atoms in its chain. • A polyamide link forms on elmination of HCl • Result = nylon 66 • Proteins are polyamides

34. Polymer Recycling Symbols LDPE = Low density PE = 0.910-0.925 g/cm3 HDPE = High density PE = 0.941-0.965 PP = Polypropylene = 0.90 V = PVC (Vinyl chloride) = 1.30-1.58