1. 1 Announcements & Agenda (03/02/07) Welcome Visitors! Please make yourselves comfortable; we will start with a quiz Welcome Visitors! Please make yourselves comfortable; we will start with a quiz Mid-term grades are only based on lecture I will give you detailed grade sheets on Monday I will give you detailed grade sheets on Monday Note: most of MT grade was based on Exam 1 Note: most of MT grade was based on Exam 1 You should read Ch 11/12 this weekend! Today Functional groups in organic chemistry (10.5) Functional groups in organic chemistry (10.5) Unsaturated compounds (11.1) Unsaturated compounds (11.1) Cis-trans isomers (11.2) Cis-trans isomers (11.2) Reactivity of unsaturated compounds (11.3) Reactivity of unsaturated compounds (11.3)

2. 2 Last Time: Organic Compounds Typical organic compounds have covalent bonds.have covalent bonds. have low melting points.have low melting points. have low boiling points.have low boiling points. are flammable.are flammable. are soluble in nonpolar solvents.are soluble in nonpolar solvents. are usually not soluble in water.are usually not soluble in water. oil (organic) and water (inorganic)

3. 3 Last Time: Alkanes (C n H 2n+2 ) nonpolar.nonpolar. insoluble in water.insoluble in water. less dense than water.less dense than water. flammable in air.flammable in air. not a lot of interestingnot a lot of interestingchemistry! …but they burn!…but they burn!

4. 4 Last Time: Intermolecular Forces- BP Increases w/ Increasing Size Last Time: Intermolecular Forces- BP Increases w/ Increasing Size Melting (blue) and boiling (pink) points of the first 14 n-alkanes in °C.

5. 5 Last Time: 4 Ways to Represent Structures of Organic Compounds (Know These!) 4.Line Structures - See next slide 1. 2. 3.

6. 6 Last Time: Naming Alkanes Give the name of CH 3 CH 3     CH 3 ─CH─CH─CH 3 CH 3 ─CH─CH─CH 3 STEP 1 Name the longest continuous chain. CH 3 CH 3 CH 3 CH 3     CH 3 ─CH─CH─CH 3 CH 3 ─CH─CH─CH 3butane

7. 7 Last Time: Naming Alkanes Give the name of CH 3 CH 3     CH 3 ─CH─CH─CH 3 CH 3 ─CH─CH─CH 3 STEP 2 Number chain. CH 3 CH 3     CH 3 ─CH─CH─CH 3 CH 3 ─CH─CH─CH 3 1 2 3 4 1 2 3 4 STEP 3 Locate substituents and name (alphabetically). 2,3-dimethylbutane

8. 8 a characteristic feature of org. molecules that behave in a predictable way.a characteristic feature of org. molecules that behave in a predictable way. composed of an atom or group of atoms.composed of an atom or group of atoms. groups that replace a hydrogen atom in the corresponding alkane.groups that replace a hydrogen atom in the corresponding alkane. a way to classify families of organic compounds.a way to classify families of organic compounds. Functional Groups (Beyond Single Bonds and Only C & H) Key Point: Functional Groups Give the Molecule their Chemical Personality

9. 9 a characteristic feature of org. molecules that behave in a predictable way.a characteristic feature of org. molecules that behave in a predictable way. composed of an atom or group of atoms.composed of an atom or group of atoms. groups that replace a hydrogen atom in the corresponding alkane.groups that replace a hydrogen atom in the corresponding alkane. a way to classify families of organic compounds.a way to classify families of organic compounds. Functional Groups (Beyond Single Bonds and Only C & H) Key Point: Differences typically depend on polarity!!!

10. 10 Alkenes and Alkynes Alkenes contain a double bond between adjacent carbon atoms. Alkynes contain a triple bond.

11. 11 Alcohols and Ethers An alcohol contains the hydroxyl (-OH) functional group. In an ether, an oxygen atom is bonded to two carbon atoms. –C–O–C–.

12. 12 Aldehydes and Ketones An aldehyde contains a carbonyl group (C=O), which is a carbon atom with a double bond to an oxygen atom. In a ketone, the carbon of the carbonyl group is attached to two other carbon atoms.

13. 13 Carboxylic Acids and Esters Carboxylic acids contain the carboxyl group, which is a carbonyl group attached to a hydroxyl group. O ║ — C—OH — C—OH An ester contains the carboxyl group between carbon atoms.

14. 14 Amines and Amides In amines, the functional group is a nitrogen atom. | | —N — —N — In amides, the hydroxyl group of a carboxylic acid is replaced by a nitrogen group.

15. 15 Summary Summary These are some of the most important biological functional groups!

16. 16 Some functional groups in consumer products BENGAY Camphor – a ketone Camphor – a ketone Menthol – an alcohol Menthol – an alcohol Methyl salicylate – an ester and a phenol Methyl salicylate – an ester and a phenolNeopsporin Miconazole – many functional groups (ether, chloro) Miconazole – many functional groups (ether, chloro) Dimethyl ether propellant Dimethyl ether propellant Halls cough Menthol- an alcohol Menthol- an alcohol

17. 17 Some functional groups in spices Nutmeg Myristicin – a polyether, an alkene, benzene ring Myristicin – a polyether, an alkene, benzene ring Elemicin Elemicin Safrole SafroleAnise Anethole – an ether, an alkene, benzene ring Anethole – an ether, an alkene, benzene ring Caraway seeds d-Carvone – a ketone d-Carvone – a ketoneSpearmint l-Carvone – a ketone l-Carvone – a ketone

18. 18 Ch. 11 Unsaturated Hydrocarbons Alkenes & Alkynes

19. 19 15 Good Practice Problems (Ch 11) 11.05, 11.07, 11.11, 11.13, 11.15, 11.17, 11.19, 11.23, 11.25, 11.27, 11.29, 11.31, 11.35, 11.37, 11.40 For Ch 10 – Do all odd problems!

20. 20 have the maximum # of H atoms attached to each C atom.have the maximum # of H atoms attached to each C atom. i.e. alkanes with single C-C bonds, C n H 2n+2i.e. alkanes with single C-C bonds, C n H 2n+2 Examples:Examples: propane: CH 3 —CH 2 —CH 3 (C 3 H 8 ) 2-methyl propane: CH 3 —CH—CH 3 (C 4 H 10 ) │ │ CH 3 CH 3 Saturated Hydrocarbons

21. 21 have fewer H atoms attached to the C chain than alkaneshave fewer H atoms attached to the C chain than alkanes are alkenes with double bondsare alkenes with double bonds If one C=C bond, C n H 2n If one C=C bond, C n H 2n Monounsaturated = 1 D.B. Monounsaturated = 1 D.B. are alkynes with triple bonds If one C ≡ C bond, C n H 2n-2 If one C ≡ C bond, C n H 2n-2 Unsaturated Hydrocarbons (C n H 2n ) NOTE: cycloalkanes can also be thought of as unsaturated b/c they have the formula (C n H 2n )

22. 22 FUN WITH KETCHUP

23. 23 Unsaturated compounds are oxidized relative to saturated compounds Oxidation of organic compounds means: Replacement of hydrogen atom with a more electronegative atom (oxygen or nitrogen) Replacement of hydrogen atom with a more electronegative atom (oxygen or nitrogen)OR Loss of H atoms & replacement with a double bond Loss of H atoms & replacement with a double bond

24. 24 Ethene (Ethylene ) Ethene or ethylene is an alkene with the formula C 2 H 4.is an alkene with the formula C 2 H 4. has two carbon atoms connected by a double bond.has two carbon atoms connected by a double bond. has two H atoms bonded to each C atom.has two H atoms bonded to each C atom. is flat with all the C and H atoms in the same plane.is flat with all the C and H atoms in the same plane. is used to accelerate the ripening of fruits.is used to accelerate the ripening of fruits.

25. 25 1-Methylcyclopropene (1-MCP) http://www.smartfresh.com/ It inhibits the release of ethylene, thus preventing ripening.

26. 26 Naming Simple Alkenes use the corresponding alkane name.use the corresponding alkane name. change the ending to –enechange the ending to –ene AlkeneIUPACCommon H 2 C=CH 2 ethene ethylene H 2 C=CH─CH 3 propene ene H 2 C=CH─CH 3 propene propylene cyclohexene

27. 27 Naming Simple Alkynes use the corresponding alkane name.use the corresponding alkane name. change the ending to –yne.change the ending to –yne. AlkyneIUPACCommon HC ≡ CHethyne acetylene HC ≡ C─CH 3 propyne

28. 28 Bond Angles in Alkenes & Alkynes According to VSEPR theory: the 3 groups bonded to C atoms in a double bond are at 120° angles.the 3 groups bonded to C atoms in a double bond are at 120° angles. alkenes are flat because the atoms in a double bond all lie in the same plane.alkenes are flat because the atoms in a double bond all lie in the same plane. the 2 groups bonded to each carbon in a triple bond are at 180° angles.the 2 groups bonded to each carbon in a triple bond are at 180° angles.

29. 29 How do you make a double bond? The 1st bond is made by “orbitals” overlapping between atoms, and is called a “sigma” (σ) bond. The 2nd bond is made by sideways p orbitals (not directly between the atoms) and is called a “pi” (π) bond. This is why a single bond can rotate. But the π bond part of a double bond can’t rotate – you’d have to break it.

30. 30 More Steroisomers: Cis-Trans Isomers In an alkene, the double bond is rigid, i.e. NO ROTATION around the double bond!is rigid, i.e. NO ROTATION around the double bond! holds attached groups in fixed positions.holds attached groups in fixed positions. makes cis/trans isomers possible.makes cis/trans isomers possible. Important in nature – such as in pheromonesImportant in nature – such as in pheromones CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH = CH CH = CH CH = CH CH = CH cis trans CH 3 cis trans CH 3 (similar groups on same side) (similar groups on opp. sides)

31. 31 Cis-Trans Isomerism Alkenes cannot have cis-trans isomers if a C atom in the double bond is attached to identical groups.Alkenes cannot have cis-trans isomers if a C atom in the double bond is attached to identical groups. Identical Identical 2-bromopropene 1,1-dibromoethene 2-bromopropene 1,1-dibromoethene (not cis or trans) (not cis or trans) (not cis or trans) (not cis or trans) H H H Br

32. 32 Unsaturated Fatty Acids Fatty acids in vegetable oils are omega-6 acids (the first double bond occurs at carbon 6 counting from the methyl group) Fatty acids in vegetable oils are omega-6 acids (the first double bond occurs at carbon 6 counting from the methyl group) A common omega-6 acid is linoleic acid A common omega-6 acid is linoleic acid CH 3 CH 2 CH 2 CH 2 CH 2 CH=CHCH 2 CH=CH(CH 2 ) 7 COOH 6 linoleic acid, a fatty acid an alkene group a carboxylic acid group

33. 33 Trans Fats In vegetable oils, the unsaturated fats usually contain cis double bonds. During hydrogenation, some cis double bonds are converted to trans double bonds (more stable) causing a change in the fatty acid structure.During hydrogenation, some cis double bonds are converted to trans double bonds (more stable) causing a change in the fatty acid structure. If a label states “partially” or “fully hydrogenated”, the fats contain trans fatty acids.If a label states “partially” or “fully hydrogenated”, the fats contain trans fatty acids.