Organic ChemistryOrganic Chemistry

Topic 10 Topic 10

Uniqueness of carbonUniqueness of carbon

Up to 4 bonds with other atomsUp to 4 bonds with other atoms Single, double and triple bondsSingle, double and triple bonds Stable covalent bonds C-C or C-HStable covalent bonds C-C or C-H Can form chains and ringsCan form chains and rings Octet cannot expand so not as Octet cannot expand so not as

reactivereactive

Describe the features of an Describe the features of an homologous serieshomologous series

Organic means carbon based Organic means carbon based compoundscompounds

Alkanes C, H all single bondsAlkanes C, H all single bonds CCnnHH2n+22n+2

Alcohols have OH group bonded to CAlcohols have OH group bonded to C CCnnHH2n+12n+1OHOH

Features of an homologous seriesFeatures of an homologous series

Same functional groupSame functional group Same general formulaSame general formula Successive members add CHSuccessive members add CH22

Gradation of physical propertiesGradation of physical properties Similar chemical propertiesSimilar chemical properties Question 1 and 2Question 1 and 2

Longer chains are stickier and Longer chains are stickier and have higher boiling points (bp)have higher boiling points (bp)

Question 3Question 3

FormulasFormulas

ethaneethane Empirical CHEmpirical CH33

Molecular CMolecular C22HH66

Structural full and condensedStructural full and condensed

animationanimation

Try ethanoic acidTry ethanoic acid

Try glucose empirical formula CHTry glucose empirical formula CH22O O M Mrr = 180 = 180

conventionsconventions

R or RR or R‘ used for hydrocarbon part‘ used for hydrocarbon part ROHROH Benzene ringBenzene ring

4 single bonds is tetrahedral 109.54 single bonds is tetrahedral 109.5oo not 90not 90oo, tetrahedral, tetrahedral

3 bonds no lone pairs form 1203 bonds no lone pairs form 120oo, , triangular planertriangular planer

Sterochemical formula wedge = Sterochemical formula wedge = forward of a page, dotted line = forward of a page, dotted line = behindbehind

nomenclaturenomenclature

Learn names of 1-6 carbonsLearn names of 1-6 carbons Page 370 in your bookPage 370 in your book

Rule #1 Name the longest chainRule #1 Name the longest chain Build pentane and show how it Build pentane and show how it

rotates around a single bondrotates around a single bond

`̀

#2 Use the functional group ending #2 Use the functional group ending as the suffix of the name page 371 in as the suffix of the name page 371 in the bookthe book

-ane, -ene, -anol,-anone, -anoic acid-ane, -ene, -anol,-anone, -anoic acid

Name the side chainName the side chain Methyl, ethyl, propylMethyl, ethyl, propyl Build 2-methyl butaneBuild 2-methyl butane This is an isomer of pentaneThis is an isomer of pentane Use the lowest # possible to number Use the lowest # possible to number

the carbon it is onthe carbon it is on What is 4-methyl pentane?What is 4-methyl pentane?

Use prefixes di-, tri-,tetra- to Use prefixes di-, tri-,tetra- to represent more than one side chain represent more than one side chain in alphabetical orderin alphabetical order

1,2 dichloropropane1,2 dichloropropane

1-chloro-2-methylpropane (notice 1-chloro-2-methylpropane (notice alphabetical order)alphabetical order)

Propan-2-olPropan-2-ol

But-1-eneBut-1-ene

If a functional group can only be in If a functional group can only be in one place leave off the numberone place leave off the number

Like propeneLike propene

Butanoic acidButanoic acid

PropanonePropanone

Name the following a) CHName the following a) CH33CHCH22CHCH22COOH COOH

b) CHClb) CHCl22CHCH22CHCH33

c) CHc) CH33CHCH22COCHCOCH33

Draw the structural formulas of the Draw the structural formulas of the following molecules a) hexanoic following molecules a) hexanoic acid acid

b) butanalb) butanal

Do questions 4-6Do questions 4-6

Handout on nomenclatureHandout on nomenclature

Do questions 1-4 pages 374-5Do questions 1-4 pages 374-5

Aromatic groupsAromatic groups Para dichloro benzenePara dichloro benzene

Structural isomersStructural isomers

Same molecular formula, different Same molecular formula, different arrangement of atomsarrangement of atoms

Different structural formulaDifferent structural formula Butane and 2-methylpropaneButane and 2-methylpropane

Draw and name all the isomers of Draw and name all the isomers of pentanepentane

Start with the straight chain and Start with the straight chain and progressively pull off the endsprogressively pull off the ends

Draw and name all the isomers of Draw and name all the isomers of CC66HH1414

Structural isomers in alkStructural isomers in alkeenesnes

Draw and name the isomers of CDraw and name the isomers of C44HH88

Draw and name the straight chain Draw and name the straight chain isomers of Cisomers of C66HH1212

Classes of compoundsClasses of compounds

Primary, secondary, tertiaryPrimary, secondary, tertiary To how many carbons is the carbon To how many carbons is the carbon

attached to the functional group attached to the functional group attachedattached

EthanolEthanol

Propan-2-olPropan-2-ol

2-methylpropan-2-ol2-methylpropan-2-ol

Trends in physical propertiesTrends in physical properties

Volatility (how easily evaporated)Volatility (how easily evaporated) Smaller less stickySmaller less sticky Branched less stickyBranched less sticky Animation 1Animation 1 Functional polar groups more sticky Functional polar groups more sticky

less volatileless volatile

alkanealkane>halogenoalkane >aldehyde >halogenoalkane >aldehyde >ketone >alcohol >acid>ketone >alcohol >acid

Solubility in waterSolubility in water

More polar more solubleMore polar more soluble Alcohol, aldehyde, ketone and acid Alcohol, aldehyde, ketone and acid

are all solubleare all soluble

Which compound has the Which compound has the lowest boiling point? lowest boiling point? CH3CH2CH(CH3)CH3 CH3CH2CH(CH3)CH3 (CH3)4C CH3CH2CH2CH2CH3 (CH3)4C CH3CH2CH2CH2CH3 CH3CH2OCH2CH3CH3CH2OCH2CH3

Do questions 8 and 9Do questions 5-8 page 382 for HW

10:2 Alkanes10:2 Alkanes

CCnnHH2n+22n+2

SaturatedSaturated HydrocarbonsHydrocarbons Strong bonds – low reactivityStrong bonds – low reactivity However, they burn easily forming However, they burn easily forming

COCO22 and H and H22OO If not enough OIf not enough O22 they form CO or C they form CO or C

(soot)(soot)

Show the equation for burning Show the equation for burning octaneoctane

Halogenation of alkanes page 384 in Halogenation of alkanes page 384 in your bookyour book

UV light and ClUV light and Cl22 yields 2 Cl yields 2 Cl.. Radicals Radicals

Called homolytic fissionCalled homolytic fission

Propagation or chain reactionPropagation or chain reaction

Show termination stepShow termination step

Do this all with molecular Do this all with molecular modelsmodels

Do question set 1 for homeworkDo question set 1 for homework

Ready for a quiz???Ready for a quiz???

10:3 Alkenes10:3 Alkenes

Unsaturated hydrocarbonsUnsaturated hydrocarbons = bond has a weak pi( )= bond has a weak pi( )bond along bond along

with the sigma (with the sigma (σσ))

Addition reactionsAddition reactions

Ni catalyst and HNi catalyst and H22

Used in margarine to make saturated Used in margarine to make saturated fats with higher melting pointsfats with higher melting points

Reaction with halogensReaction with halogens Propene with BrPropene with Br2 2 (test for a = bond) (test for a = bond)

Hydrogen halides Hydrogen halides

Produce halogenoalkanesProduce halogenoalkanes Propene with HClPropene with HCl

HI weaker bonds more reactive than HI weaker bonds more reactive than HBr then HClHBr then HCl

Reaction with waterReaction with water

Called hydrationCalled hydration Alkene to alcoholAlkene to alcohol Use conc. HUse conc. H22SOSO44 as a catalyst and as a catalyst and

steamsteam Ethene to ethanol (industrial use to Ethene to ethanol (industrial use to

get alcohol)get alcohol)

polymerizationpolymerization

PolyethylenePolyethylene Monomer isMonomer is

Polymer isPolymer is

Polyvinylchloride (PVC)Polyvinylchloride (PVC)

Teflon (polytetrafluoroethene) what Teflon (polytetrafluoroethene) what is the starting material?is the starting material?

Do questions 10-12Do questions 10-12

10:4 alcohols10:4 alcohols

CCnnHH2n+12n+1OHOH Nomenclature handout alcoholsNomenclature handout alcohols -OH (hydroxyl group) functional -OH (hydroxyl group) functional

groupgroup Shorter chains soluble in waterShorter chains soluble in water

combustioncombustion

Like alkanesLike alkanes Equation for burning of ethanolEquation for burning of ethanol

Longer chains give off more energyLonger chains give off more energy

oxidationoxidation

Alcohols with orange KAlcohols with orange K22CrCr22OO7 7 reduce it to reduce it to green Crgreen Cr22OO33 (breathalyzer test) (breathalyzer test)

Primary alcohols oxidize to aldehyde Primary alcohols oxidize to aldehyde then to acidsthen to acids

Ethanol with KEthanol with K22CrOCrO7 7

Distill to get ethanal (apple smell)Distill to get ethanal (apple smell)

Reflux to get acidReflux to get acid Lab activity distillation and refluxingLab activity distillation and refluxing

Secondary alcohols make ketonesSecondary alcohols make ketones Propan-2-ol (reflux) Propan-2-ol (reflux)

Tertiary alcohols do not readily Tertiary alcohols do not readily oxidizeoxidize

Do questions 13-14Do questions 13-14 Do question set 2 for homeworkDo question set 2 for homework

10:5 Halogenoalkanes10:5 Halogenoalkanes

CCnnHH2n+12n+1X X = halogenX X = halogen Used as intermediaries in other Used as intermediaries in other

reactionsreactions Polar CPolar Cδδ++ - Cl - Clδδ- - C e- deficientC e- deficient Nucleophiles e- rich lone pairs Nucleophiles e- rich lone pairs

attack the e- deficient areaattack the e- deficient area SSNN substitution nucleophile reactions substitution nucleophile reactions

Examples of nucleophiles HExamples of nucleophiles H22O OHO OH-- NHNH33 CN CN--

SN2 (bimolecular) primary SN2 (bimolecular) primary halogenoalkaneshalogenoalkanes

SSNN1 tertiary halogenoalkanes1 tertiary halogenoalkanes UnimolecularUnimolecular Secondary halogenoalkanes can Secondary halogenoalkanes can

undergo eitherundergo either

Go to page 395 and draw the 2 Go to page 395 and draw the 2 mechanisms showing curly arrowsmechanisms showing curly arrows

AnimationAnimation Do questions 15-17Do questions 15-17

10:6 Reaction pathways 10:6 Reaction pathways

see page 406 in the textbook fill in see page 406 in the textbook fill in the reagents and conditions neededthe reagents and conditions needed

Convert 1-chlorobutane into butanoic Convert 1-chlorobutane into butanoic acid acid

Do proponal from 1-bromopropaneDo proponal from 1-bromopropane

1,2,3 trichlorpropane from propene1,2,3 trichlorpropane from propene

EstersEsters Formed when organic acids react Formed when organic acids react

with alcoholswith alcohols Fragrances and flavorsFragrances and flavors RCOORRCOOR‘‘

Draw methyl methanoate from Draw methyl methanoate from methanol and ethanoic acidmethanol and ethanoic acid

Ester from methanoic acid and propanolEster from methanoic acid and propanol Name and draw the structureName and draw the structure Nomenclature handout estersNomenclature handout esters

Do question 7Do question 7 Ester labEster lab

Do questions 18-20Do questions 18-20 Do questions 1-4,6-9,11 pages 416 Do questions 1-4,6-9,11 pages 416

and 417 in your textbookand 417 in your textbook Do the SL questions (1-11) in your Do the SL questions (1-11) in your

study guide on page 74study guide on page 74 Homework question set 3Homework question set 3 Quiz 10:3-6Quiz 10:3-6