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AnnouncementsAnnouncements & Agenda& Agenda (03/02/07)(03/02/07)Welcome Visitors! Please make yourselves Welcome Visitors! Please make yourselves comfortable; we will start with a quiz comfortable; we will start with a quiz Mid-term grades are only based on lectureMid-term grades are only based on lecture I will give you detailed grade sheets on MondayI will give you detailed grade sheets on Monday Note: most of MT grade was based on Exam 1Note: most of MT grade was based on Exam 1

You should read Ch 11/12 this weekend!You should read Ch 11/12 this weekend!TodayToday 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)

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Last Time: Organic CompoundsLast Time: Organic Compounds

Typical organic compoundsTypical 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 are soluble in nonpolar solvents.solvents.

• are usually not soluble in are usually not soluble in water.water.

oil (organic) and water (inorganic)

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Last Time: Alkanes (CLast Time: Alkanes (CnnHH2n+22n+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 not a lot of interestinginteresting

chemistry!chemistry!

• ……but they burn!but they burn!

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Last Time: Intermolecular Forces- Last Time: Intermolecular Forces- BP Increases w/ Increasing Size BP Increases w/ Increasing Size

Melting (blue) and boiling (pink) points of the first 14 n-alkanes in °C.

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Last Time: 4 Ways to Represent Structures Last Time: 4 Ways to Represent Structures of Organic Compounds (Know These!)of Organic Compounds (Know These!)

4. Line Structures- See next slide

1.

2.

3.

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Last Time: Naming AlkanesLast Time: Naming Alkanes

Give the name of CHGive the name of CH3 3 CHCH33

CHCH33─CH─CH─CH─CH─CH─CH33

STEP 1 STEP 1 Name the longest continuous chain.Name the longest continuous chain.

CHCH3 3 CHCH33

CHCH33─CH─CH─CH─CH─CH─CH33

butanebutane

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Last Time: Naming AlkanesLast Time: Naming AlkanesGive the name of CHGive the name of CH3 3 CHCH33

CHCH33─CH─CH─CH─CH─CH─CH33

STEP 2 STEP 2 Number chain.Number chain. CHCH3 3 CHCH33

CHCH33─CH─CH─CH─CH─CH─CH33

1 2 3 41 2 3 4

STEP 3 STEP 3 Locate substituents and name (alphabetically). Locate substituents and name (alphabetically).

2,3-dimethyl2,3-dimethylbutanebutane

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• a a characteristiccharacteristic feature of org. molecules feature of org. molecules that behave in a predictable way. 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 groups that replace a hydrogen atom in the corresponding alkane.the corresponding alkane.

• a way to classify families of organic a way to classify families of organic compounds.compounds.

Functional Groups (Beyond Single Functional Groups (Beyond Single Bonds and Only C & H)Bonds and Only C & H)

Key Point: Functional Groups Give the Key Point: Functional Groups Give the Molecule their Chemical PersonalityMolecule their Chemical Personality

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• a a characteristiccharacteristic feature of org. molecules feature of org. molecules that behave in a predictable way. 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 groups that replace a hydrogen atom in the corresponding alkane.the corresponding alkane.

• a way to classify families of organic a way to classify families of organic compounds.compounds.

Functional Groups (Beyond Single Functional Groups (Beyond Single Bonds and Only C & H)Bonds and Only C & H)

Key Point: Differences typically depend Key Point: Differences typically depend on polarity!!!on polarity!!!

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Alkenes and AlkynesAlkenes and Alkynes

AlkenesAlkenes contain a contain a double bond double bond between adjacent between adjacent carbon atoms.carbon atoms.

AlkynesAlkynes contain a contain a triple bond.triple bond.

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Alcohols and EthersAlcohols and Ethers

An An alcoholalcohol contains contains the the hydroxyl (-OH)hydroxyl (-OH) functional group.functional group.

In anIn an etherether,, an oxygen an oxygen atom is bonded to two atom is bonded to two carbon atoms. carbon atoms.

––C–O–C– . C–O–C– .

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Aldehydes and KetonesAldehydes and Ketones

An An aldehydealdehyde contains a contains a carbonyl groupcarbonyl group (C=O), which (C=O), which is a carbon atom with a is a carbon atom with a double bond to an oxygen double bond to an oxygen atom.atom.

In a In a ketoneketone, , the carbon of the carbon of the the carbonyl groupcarbonyl group is is attached to two other carbon attached to two other carbon atoms.atoms.

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Carboxylic Acids and EstersCarboxylic Acids and Esters

Carboxylic acidsCarboxylic acids contain the contain the carboxyl groupcarboxyl group, which is a , which is a carbonyl groupcarbonyl group attached to a attached to a hydroxyl grouphydroxyl group. .

OO ║║

—— CC——OHOH

An An esterester contains the contains the carboxyl groupcarboxyl group between between carbon atoms.carbon atoms.

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Amines and AmidesAmines and Amides

In In aminesamines, the functional , the functional group is a nitrogen atom.group is a nitrogen atom.

||

——N —N —

In In amidesamides, the hydroxyl , the hydroxyl group of a carboxylic group of a carboxylic acid is replaced by a acid is replaced by a nitrogen group.nitrogen group.

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Summary Summary

These are some of the most important These are some of the most important biological functional groups!biological functional groups!

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Some functional groups in Some functional groups in consumer productsconsumer products

BENGAYBENGAY Camphor – a ketoneCamphor – a ketone Menthol – an alcoholMenthol – an alcohol Methyl salicylate – an ester and a phenolMethyl salicylate – an ester and a phenolNeopsporin Neopsporin Miconazole – many functional groups (ether, chloro)Miconazole – many functional groups (ether, chloro) Dimethyl ether propellantDimethyl ether propellantHalls coughHalls cough Menthol- an alcoholMenthol- an alcohol

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Some functional groups in spicesSome functional groups in spices

NutmegNutmeg Myristicin – a polyether, an alkene, benzene ringMyristicin – a polyether, an alkene, benzene ring ElemicinElemicin SafroleSafrole

AniseAnise Anethole – an ether, an alkene, benzene ringAnethole – an ether, an alkene, benzene ring

Caraway seedsCaraway seeds d-Carvone – a ketoned-Carvone – a ketone

SpearmintSpearmint l-Carvone – a ketonel-Carvone – a ketone

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Ch. 11 Unsaturated HydrocarbonsCh. 11 Unsaturated Hydrocarbons

Alkenes & AlkynesAlkenes & Alkynes

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15 Good Practice Problems (Ch 11)15 Good Practice Problems (Ch 11)

11 22 33 44 55

11.05, 11.07, 11.11, 11.13, 11.15, 11.05, 11.07, 11.11, 11.13, 11.15, 11.17, 11.19, 11.23, 11.25, 11.27, 11.17, 11.19, 11.23, 11.25, 11.27, 11.29, 11.31, 11.35, 11.37, 11.40 11.29, 11.31, 11.35, 11.37, 11.40

For Ch 10 – Do all odd problems!For Ch 10 – Do all odd problems!

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• have the maximum # of H atoms attached to have the maximum # of H atoms attached to each C atom.each C atom.

• i.e. alkanes with single C-C bonds, Ci.e. alkanes with single C-C bonds, CnnHH2n+22n+2

• Examples: Examples:

propane: CHpropane: CH33—CH—CH22—CH—CH3 3 ((CC33HH88))

2-methyl propane: 2-methyl propane: CHCH33—CH—CH—CH—CH3 3 ((CC44HH1010)) ││ CHCH33

Saturated HydrocarbonsSaturated Hydrocarbons

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• have fewer H atoms have fewer H atoms attached to the C chain attached to the C chain than alkanesthan alkanes

• are are alkenesalkenes with double with double bonds bonds

• If one C=C bond, CIf one C=C bond, CnnHH2n2n

• Monounsaturated = 1 D.B.Monounsaturated = 1 D.B.

are are alkynesalkynes with triple with triple bonds bonds

• If one CIf one C≡≡CC bond, bond, CCnnHH2n-22n-2

Unsaturated HydrocarbonsUnsaturated Hydrocarbons

NOTE: cycloalkanes can also be thought of as unsaturated b/c they have the formula (C(CnnHH2n2n))

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FUN WITH KETCHUPFUN WITH KETCHUP

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Unsaturated compounds are Unsaturated compounds are oxidizedoxidized relative to saturated compoundsrelative to saturated compounds

Oxidation of organic compounds means:Oxidation of organic compounds means:

Replacement of hydrogen atom with a more Replacement of hydrogen atom with a more electronegative atom (oxygen or nitrogen)electronegative atom (oxygen or nitrogen)

OROR

Loss of H atoms & replacement with a double Loss of H atoms & replacement with a double bondbond

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Ethene (EthyleneEthene (Ethylene))

Ethene or ethyleneEthene or ethylene• is an alkene with the formula is an alkene with the formula

CC22HH44..• has two carbon atoms has two carbon atoms

connected by a double bond. connected by a double bond. • has two H atoms bonded to has two H atoms bonded to

each C atom.each C atom.• is flat with all the C and H is flat with all the C and H

atoms in the same plane.atoms in the same plane.• is used to accelerate the is used to accelerate the

ripening of fruits.ripening of fruits.

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1-Methylcyclopropene (1-MCP)1-Methylcyclopropene (1-MCP)

http://www.smartfresh.com/http://www.smartfresh.com/

It inhibits the release of ethylene, thus It inhibits the release of ethylene, thus preventing ripening.preventing ripening.

CH3

1-MCP

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Naming Simple AlkenesNaming Simple Alkenes

• use the corresponding alkane name.use the corresponding alkane name.• change the ending to –change the ending to –eneene

AlkeneAlkene IUPACIUPAC CommonCommon

HH22C=CHC=CH22 ethetheneene ethylethyleneene

HH22C=CHC=CH──CHCH33 proppropeneene propyleneene

cyclohexcyclohexeneene

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Naming Simple AlkynesNaming Simple Alkynes

• use the corresponding alkane name.use the corresponding alkane name.• change the ending to –change the ending to –yneyne..

AlkyneAlkyne IUPACIUPAC CommonCommon

HCHC≡≡CHCH ethethyneyne acetyleneacetylene

HCHC≡≡CC──CHCH33 proppropyneyne

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Bond Angles in Alkenes & AlkynesBond Angles in Alkenes & Alkynes

According to VSEPR theory: According to VSEPR theory: • the 3 groups bonded to C the 3 groups bonded to C

atoms in a double bond are atoms in a double bond are at 120at 120° ° angles.angles.

• alkenes are flat because thealkenes are flat because the atoms in a double bondatoms in a double bond all all lie in the same plane.lie in the same plane.

• the 2 groups bonded to the 2 groups bonded to each carbon in a triple bond each carbon in a triple bond are at 180° angles.are at 180° angles.

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How do you make a double bond?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.

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More Steroisomers: More Steroisomers: CisCis--TransTrans Isomers IsomersIn an alkene, the double bond 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

CHCH33 CHCH33 CH CH33

CH = CHCH = CH CH = CHCH = CH

ciscis transtrans CHCH33

(similar groups on same side) (similar groups on opp. sides)(similar groups on same side) (similar groups on opp. sides)

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Cis-Trans IsomerismCis-Trans Isomerism• Alkenes cannot have cis-trans isomers if a C atom Alkenes cannot have cis-trans isomers if a C atom

in the double bond is attached to in the double bond is attached to identical groupsidentical groups..

IdenticalIdentical Identical Identical

2-bromopropene2-bromopropene 1,1-dibromoethene 1,1-dibromoethene (not cis or trans)(not cis or trans) (not cis or trans) (not cis or trans)

C C

H Br

H CH3

C C

H Br

BrH

H

H

H Br

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Unsaturated Fatty AcidsUnsaturated Fatty Acids

Fatty acids in vegetable oils are omega-6 acids (the Fatty acids in vegetable oils are omega-6 acids (the first double bond occurs at carbon 6 counting from first double bond occurs at carbon 6 counting from the methyl group)the methyl group)

A common omega-6 acid is linoleic acidA common omega-6 acid is linoleic acid

CHCH33CHCH22CHCH22CHCH22CHCH22CH=CHCHCH=CHCH22CH=CH(CHCH=CH(CH22))77COOHCOOH

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linoleic acid, a fatty acid linoleic acid, a fatty acid

an alkene group

a carboxylic acid group

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TransTrans Fats Fats

In vegetable oils, the unsaturated fats usually In vegetable oils, the unsaturated fats usually contain contain ciscis double bonds. double bonds.

• During hydrogenation, some During hydrogenation, some cis cis double bonds are double bonds are converted to converted to trans trans double bonds (more stable) double bonds (more stable) causing a change in the fatty acid structure.causing a change in the fatty acid structure.

• If a label states “partially” or “fully hydrogenated”, If a label states “partially” or “fully hydrogenated”, the fats contain the fats contain transtrans fatty acids. fatty acids.