1. Organic Compounds containing Oxygen, Halogen, or Sulfur

2. Alcohols, Ethers, Alkyl Halides & Thiols ROH ROR RX RSH All of these compounds contain a carbon atom that is singly bonded to a heteroatom (other than H or C)! Alcohols & ethers can be considered organic derivatives of water Replacing H(s) with one or two alkyl groups HOH; ROH; ROR

3. Alcohols Structural Characteristics R-OH -OH (hydroxyl = functional group) -OH is bonded to a saturated C atom! Classification Primary (1˚) C-C-OH Secondary (2˚) C-C-OH | C Tertiary (3˚) C | C-C-OH | C

4. Alcohol Nomenclature IUPAC 1.Name the longest chain (drop the “e” and add “ol” at the end) to which -OH is attached. 2.# the chain from the end nearest the -OH* (# the position of the -OH group). 3.Name/locate any substituents. 4.For rings, -OH is on C#1.

5. IUPAC naming examples Ex.: CH 3 OH Methanol CH 3 CH 2 CH 2 OH1-propanol CH 3 CHCH 3 | OH 2-propanol 3,4-dimethylcyclohexanol Alcohols with >1 -OH groups Ex.:CH 2 CH 2 | |1,2-ethanediol OH OH l

6. Alcohol Nomenclature Common (name “R” as an alkyl group) Alkyl group name + alcohol Ex.: CH 3 OH Methyl alcohol CH 3 CHCH 3 |Isopropyl alcohol OH Alcohols with >1 -OH groups Ex.:

7. Important Common Alcohols IUPAC Methanol Ethanol 2-propanol 1,2-ethanediol 1,2-propanediol 1,2,3-propanetriol Common Methyl alcohol Ethyl alcohol Isopropyl alcohol Ethylene glycol Propylene glycol Glycerol (glycerin) For survival in northern winters, many fish and insects produce large amounts of glycerol that dissolve in their blood, thereby lowering the freezing point.

8. How does % relate to “proof”?

9. Constitutional Isomerism Positional Ex.: butanol 1-butanol 2-butanol Skeletal Ex.: butanol2-butanol sec-butyl alcohol 2-methyl-2-propanol tert-butyl alcohol

10. Physical Properties of Alcohols Alcohols have both Polar & Nonpolar character!(-OH) (alkyl) Properties are determined by which portion dominates Short chain (<6) - polar end dominates Long chain (6+) - nonpolar end dominates BP increases with increasing # of C atoms Effect of London Dispersion Forces Water solubility Short chain - soluble Long chain - insoluble Alcohols can Hydrogen bond (better with small chain alcohols) affects BP & Solubility in Water Alkanes cannot Hydrogen bond

11. (a) The polar hydroxyl functional group dominates the physical properties of methanol. (b) Conversely, the nonpolar portion of 1- octanol dominates its physical properties.

13. Chemical Reactions of Alcohols Combustion CH 3 OH + O 2 --> CO 2 + H 2 O Two types of Dehydration! Intramolecular Alcohol dehydration Conditions: 180˚C and H 2 SO 4 catalyst Result: formation of alkene (elimination/condensation rxn) Ex.: C-C-OH ----> C=C + H 2 O Ex.: 2-butanol --> Zaitsev’s rule: major product is alkene w/ greatest # of alkyl groups

14. Chemical Reactions of Alcohols Intermolecular Alcohol dehydration Conditions: 140˚C (lower temp!) and H 2 SO 4 catalyst Result: formation of ether (R-O-R) (condensation rxn) Ex.: C-OH + HO-C ----> C-O-C + H 2 O

15. Halogenation Reactions R-C-OH + X 2 ----> R-C-X 2 + H 2 O Not a particularly common reaction, however

16. Oxidation Reactions Oxidation results in an increase in the number of C-O bonds or a decrease in the number of C-H bonds. 1˚ alcohol ---> aldehyde ---> carboxylic acid 2˚ alcohol ---> ketone 3˚ alcohol ---> No Reaction! The oxidation of ethanol is the basis for the “breathalyzer test.”

17. Preparation of Alcohols Alcohols can be prepared in two major ways: Alkene hydration Ex.: CH 2 =CH 2 + H 2 O ----> CH 3 CH 2 OH Addition of H 2 to a carbonyl group (-C=O) Ex.: Aldehyde + H 2 ----> 1˚ alcohol Ketone + H 2 ----> 2˚ alcohol

18. Phenols Structural Characteristics -OH is attached to a C that is part of an aromatic ring. Ar-OH

19. Nomenclature of Phenols Phenol = “phenyl” + “alcohol” IUPAC rules are same as for benzene derivatives. Parent ring is “phenol”. Ex.:

20. Physical & Chemical Properties of Phenols Flammable, like alcohols Phenols cannot be dehydrated. Oxidation occurs only with strong oxidizing agents. Halogenation Weak acids in solution (K a ~10 -10 )

21. Occurance & Uses of Phenols Antiseptics (but phenol derivatives are much safer than phenol itself). Mouthwashes, Lysol, etc. Antioxidant - several phenols are preferentially oxidized Food additives Vit. E Flavoring agents Irritants: poison ivy & poison oak Many commercially baked goods contain the antioxidants BHA and BHT to help prevent spoilage. Nutmeg tree fruit. A phenolic compound, isoeugenol, is responsible for the odor associated with nutmeg.

22. Ethers Structural Characteristics Functional group = -C-O-C- Remember ascorbic acid? R-O-R R-O-R’ R-O-Ar Ar-O-Ar

23. Nomenclature of Ethers IUPAC Select longest C chain = base name. Change -yl ending of other group to -oxy. (ie. Methyl becomes methoxy) Place alkoxy name (w/ locator #) in front of base chain name Ex.: C-C-O-C-C-C-C Common Name the two alkyl groups (alpha order) attached to the O and add the word “ether”.

24. Examples:

25. Isomerism Consitutional Partitioning of C atoms (by O) - positional! Isomers of individual alkyl groups Ex.: C 4 ethers Functional Group Isomers (1st time we encounter this possibility) Consitutional isomers with different functional groups Ex.: C 3 ether and C 3 alcohol

26. Physical & Chemical Properties Physical BP = to alkanes; lower than alcohols No H-bonding w/ self possible Water soluble Can H-bond w/ water NP substances are generally soluble in ethers Act as anesthetics Diethyl ether Chemical Flammable React w/ O 2 to form unstable (explosive) ccompounds Unreactive w/ acids and oxidizing agents Halogenation Prepared by intermolecular dehydration of 1˚ alcohols

27. Alkyl Halides: Incoming halogen atom (orange sphere) replaces a hydrogen atom in the alkane model. Naming: Treat halogen atoms like alkyl groups. F = fluoro; Cl = chloro; Br = bromo; I = iodo Ex.: CH 3 -CHBr-CHBr-CHI-CH 2 -CH 3

28. Halogenation Reactions General equation: RH + X 2 → RX + HX Hydrocarbon + Halogen  Halogenated + acid (diatomic) hydrocarbon Ex.CH 4 + Cl 2 -->CH 3 Cl + HCl Highly exothermic reaction: can lead to an explosion

29. The process can continue to alter the resulting products as long as the halogen remains in sufficient quantities to drive further reactions. (The halogen would be the __________ reactant.)

30. Space-filling models of the four ethyl halides. Do these molecules act as polar or non-polar?

31. Chlorofluorocarbons (CFCs) Developed in the 1930's Very stable compounds composed of C, F, Cl, & H Freon is the tradename: Trichlorofluoromethane Dichlorodifluoromethane Trichloro-trifluoroethane Dichloro-tetrfluoroethane Chloropentafluoroethane

32. Safe, non-toxic, non-flammable alternative to dangerous substances (e.g. ammonia) for aerosol-spray propellants, refrigerants, solvents, and foam-blowing agents

33. CFCs and refrigeration CFCs and propellants

34. UV radiation in the stratosphere

35. The Ozone Layer Chemistry CFCl 3 + U UU UV Light ==> CFCl 2 + Cl Cl + O 3 ==> ClO + O 2 ClO + O ==> Cl + O 2 The chlorine free radical atom is then able to attack another ozone molecule Cl + O 3 ==> ClO + O 2 ClO + O ==> Cl + O 2 and again... Cl + O 3 ==> ClO + O 2 ClO + O ==> Cl + O 2 and again... thousands of times! A catalyst!

36. The ozone destruction process requires conditions cold enough (-80 o C) for stratospheric clouds to form. Once these stratospheric clouds form the process can take place, even in warmer conditions

37. Ozone consumption has been greatly reduced, 1997 ozone hole 2003 ozone hole however CFCs may linger for another 150 years in the atmosphere Ozone layer thickness

38. Thiols = Mercaptans: sulfhydryl group (-SH) bonded to a saturated C atom Alcohol - R-OH C-C-OH (ethanol) (ethyl alcohol) Thiol - R-SH C-C-SH (ethanethiol) (ethyl mercaptan)

39. Properties of Thiols Physical Low BP No H-bonding Strong odor Skunks (3-methyl-1- butanethiol) Methanethiol (additive to natural gas) Morning breath Onions (1-propanethiol) Chemical Oxidation-Reduction 2 thiols Disulfide Important in Protein chemistry

40. Thioethers - replace the “O” with “S” (R-S-R) C-S-C C-S-C-C-C Ar-S-C C=C-S-C C=C-C-S-C C=C-C-S-S-C-C=C Morning Breath = Hydrogen sulfide Methanethiol Dimethyl sulfide… Onions Garlic Disulfides are important in some protein structures.

41. What do you need to know? Structural characteristics (know the functional group) Alcohol Phenol Ether Sulfur Analogs Isomers Nomenclature (the rules for naming the molecules) Common & IUPAC Physical properties (basic/simple) BP; Solubility; Flammability Occurrence and uses (common) Natural (ex.: menthol, skunk, nutmeg, clove, garlic, onion) Synthetic (ex.: antiseptics, racing fuel, de-icers, antioxidants, anesthetics) Preparation (what basic reactions produce the molecules) Alcohols - alkene hydration; Phenols - benzene hydration Ethers - intermolecular alcohol dehydration Characteristic reactions of the molecules Combustion; dehydration; halogenation; oxidation