Ch. 11: Carbon Ch. 11: Carbon A Multifarious ElementA Multifarious Element

Why Carbon?Why Carbon?

• VersatilityVersatility

• Single, double, triple bondsSingle, double, triple bonds

• Structural diversityStructural diversity

Short-hand for expressing Short-hand for expressing carbon-based compoundscarbon-based compounds

• CC44HH1010: butane: butane

• Structural formulaStructural formula

• Condensed structural formulaCondensed structural formula

• Carbon skeleton formulaCarbon skeleton formula

• CC44HH88

• CC44HH66

IsomersIsomers

• Isomers – same composition, diff. Isomers – same composition, diff. structuresstructures

• Structural isomers: same # atoms, Structural isomers: same # atoms, diff. structuresdiff. structures

Ethanol (CEthanol (C22HH66O) vs. dimethylether O) vs. dimethylether (C(C22HH66O)O)

Problems Problems

•Draw all isomers of C3H8O. There are 3.

•Draw all isomers of C4H8Br2. There are 9.

StereoisomersStereoisomers

• Same formula, diff. orientationSame formula, diff. orientation

• Two types:Two types:

• 1) geometric1) geometric

• 2) optical isomers2) optical isomers

Geometric isomersGeometric isomers

• Require double bond!Require double bond!

•CisCis vs. vs. transtrans

Optical isomersOptical isomers

• Nonsuperimposable mirror imagesNonsuperimposable mirror images

• Called chiral molecules (chirality)Called chiral molecules (chirality)

• Pairs of chiral molecules = Pairs of chiral molecules = enantiomersenantiomers

Classes of Carbon-Containing Classes of Carbon-Containing CmpdsCmpds

• HydrocarbonsHydrocarbons

• Only C & HOnly C & H

• Alkane: CAlkane: CnnHH2n+22n+2

• (Saturated every C-C bond single)(Saturated every C-C bond single)

• Alkene: CAlkene: CnnHH2n 2n (at least one double (at least one double bond btwn C’s)bond btwn C’s)

• (Unsaturated (Unsaturated double, triple bonds) double, triple bonds)

Classes of Carbon-Containing Classes of Carbon-Containing CmpdsCmpds

• Alkyne: CAlkyne: CnnHH2n-22n-2 (at least one triple (at least one triple bond btwn C’s)bond btwn C’s)

• Cyclohydrocarbons: rings of carbonCyclohydrocarbons: rings of carbon

• Aromatic: rings w/pi-bondingAromatic: rings w/pi-bonding– benzenebenzene

Naming AlkanesNaming Alkanes

• Suffix: -aneSuffix: -ane• Count out longest carbon chainCount out longest carbon chain• Prefixes:Prefixes:

• 1C meth-1C meth-• 2C eth-2C eth-• 3C prop-3C prop-• 4C but-4C but-• 5C pent-5C pent-• 6C hex-6C hex-• 7C hept-7C hept-• 8C oct-8C oct-• 9C non-9C non-• 10C dec-10C dec-

Naming AlkanesNaming Alkanes

• Hydrocarbon substitution = alkyl groupsHydrocarbon substitution = alkyl groups• Meth Meth methyl, etc. methyl, etc.

• Use number, followed by “-”, to designate placement of substituentUse number, followed by “-”, to designate placement of substituent– 2-methylpentane2-methylpentane

• If 2 or more of same subs. If 2 or more of same subs. di, tri, tetra, etc. di, tri, tetra, etc.– 2,3-dimethylpentane2,3-dimethylpentane

• If more than one different alkyl group, use alphabetic orderingIf more than one different alkyl group, use alphabetic ordering– Butyl precede ethyl precedes methylButyl precede ethyl precedes methyl

• 4-ethyl-3-methylheptane4-ethyl-3-methylheptane

• In naming hydrocarbons always go with longest carbon-In naming hydrocarbons always go with longest carbon-chainchain

Draw out the following alkanes Draw out the following alkanes and rename them, if neededand rename them, if needed

• HexaneHexane

• 2-methylhexane2-methylhexane

• 2,2-diethylpropane2,2-diethylpropane

• 4-ethyl-2-methylnonane4-ethyl-2-methylnonane

• Now, I’ll draw some and you name Now, I’ll draw some and you name themthem

Naming Alkenes, alkynesNaming Alkenes, alkynes

• Start counting carbon chain from lowest Start counting carbon chain from lowest carbon containing double/triple bondcarbon containing double/triple bond

• 1-propene, not 2-propene1-propene, not 2-propene

• Use number, followed by “-”, to Use number, followed by “-”, to designate placement of double or triple designate placement of double or triple bondbond– 1-butene1-butene– 2-octyne2-octyne

Draw the following and if there Draw the following and if there is isomerism draw both is isomerism draw both structures and name themstructures and name them• 1-hexene1-hexene

• 2-hexene2-hexene

• 3-heptyne3-heptyne

• 2-methyl-3-heptyne2-methyl-3-heptyne

• Now, I’ll draw some and you name Now, I’ll draw some and you name themthem

Naming HalohydrocarbonsNaming Halohydrocarbons

• Same rules applySame rules apply– In alphabetical orderIn alphabetical order– Bromine Bromine bromo bromo– chlorine chlorine chloro chloro– fluorine fluorine fluoro fluoro– iodine iodine iodo iodo

• Ex: 2-chlorobutaneEx: 2-chlorobutane

• Practice (fix if necessary):Practice (fix if necessary):• 3-bromo-2-chloropentane3-bromo-2-chloropentane• 3,3-diiodobutane3,3-diiodobutane• Now, I’ll draw some and you name themNow, I’ll draw some and you name them

Naming Aromatic CmpdsNaming Aromatic Cmpds

• Monosubstitution:Monosubstitution:– Methylbenzene Methylbenzene toluene toluene– PhenolPhenol– Aniline Aniline

• Disubstitution:Disubstitution:• oo- = ortho- = ortho•mm- = meta- = meta•pp- = para- = para

Practice Practice

• Chlorobenzene (does it make a Chlorobenzene (does it make a difference where you put the Cl?)difference where you put the Cl?)

• Draw all isomers (and name them) of Draw all isomers (and name them) of a benzene that has 1 bromine and a benzene that has 1 bromine and one fluorineone fluorine– Which combinations are disallowed and Which combinations are disallowed and

why?why?

Other functional groupsOther functional groups

• Functional group = characteristic Functional group = characteristic grouping or arrangement of atomsgrouping or arrangement of atoms

• Alcohols = R-OHAlcohols = R-OH

• MethanMethanolol, ethan, ethanolol, propan, propanolol, etc., etc.

• Structural isomers of alcoholsStructural isomers of alcohols

• 1,2-ethanediol = ethylene glycol1,2-ethanediol = ethylene glycol

Practice: rename if Practice: rename if necessarynecessary

• 1-propanol1-propanol

• 2-propanol2-propanol

• 3-propanol 3-propanol

• Now, I’ll draw some and you name Now, I’ll draw some and you name themthem

Other functional groupsOther functional groups

• Ether: ROR’Ether: ROR’1) Select the longest carbon chain and 1) Select the longest carbon chain and

name it as the correct alkane.name it as the correct alkane.2) Change the “-yl” ending of the other 2) Change the “-yl” ending of the other

(shorter) hydrocarbon group to “-oxy” (shorter) hydrocarbon group to “-oxy” to to

obtain the alkoxy group name.obtain the alkoxy group name.3) Combine the two names giving the 3) Combine the two names giving the

alkoxy group name first.alkoxy group name first.

Practice Practice

• DimethyletherDimethylether

• ButoxyhexaneButoxyhexane

• methoxyethanemethoxyethane

• Now, I’ll draw some and you name Now, I’ll draw some and you name themthem

Other functional groupsOther functional groups

• AminesAmines

• RNHRNH22

• Putrescine = 1,4-butanediaminePutrescine = 1,4-butanediamine

• Cadaverine = 1,5-pentanediamineCadaverine = 1,5-pentanediamine

Practice Practice

• TriethylamineTriethylamine

• TriisopropylamineTriisopropylamine

• Now, I’ll draw some and you name Now, I’ll draw some and you name themthem

Other functional groupsOther functional groups

• AldehydesAldehydes• RCOHRCOH• Start counting the carbon-chain from the C=OStart counting the carbon-chain from the C=O• MethanMethanalal, butan, butanalal, hexan, hexanalal

• KetonesKetones• RCOR’RCOR’• Start counting the carbon-chain from the C=OStart counting the carbon-chain from the C=O• 2-propan2-propanoneone, 3-heptan, 3-heptanoneone

Practice Practice

• MethanalMethanal

• HexanalHexanal

• 2-pentanone2-pentanone

• 4-decanone4-decanone

• Now, I’ll draw some and you name Now, I’ll draw some and you name themthem

Other functional groupsOther functional groups

• Carboxylic acidsCarboxylic acids• RCOOHRCOOH• Start counting the carbon-chain from the C=OStart counting the carbon-chain from the C=O• Methanoic acid, ethanoic acid, etc.Methanoic acid, ethanoic acid, etc.

• EstersEsters• RCOOR’RCOOR’• Start counting the carbon-chain from the C=OStart counting the carbon-chain from the C=O• -OR’ -OR’ takes on alkyl name takes on alkyl name• RCO RCO takes on –oate suffix takes on –oate suffix• Thus, HCOOCHThus, HCOOCH33 methyl methanoate methyl methanoate• By the way, acetate = ethanoateBy the way, acetate = ethanoate

Practice Practice

• Hexanoic acidHexanoic acid

• 2-methylpropanoic acid (give its other name)2-methylpropanoic acid (give its other name)

• Hexyl ethanoateHexyl ethanoate

• Butyl butanoateButyl butanoate

• 3-methylbutyl ethanoate (has a more 3-methylbutyl ethanoate (has a more common name)common name)

• Now, I’ll draw some and you name themNow, I’ll draw some and you name them

Other functional groupsOther functional groups

• AmidesAmides

• RCONRRCONR22

• Ex: methanamide, ethanamideEx: methanamide, ethanamide

PolymersPolymers

• Huge molecules with repeating monomers Huge molecules with repeating monomers (subunits)(subunits)

• ThermoplasticsThermoplastics (polyethylene, (polyethylene, styrofoam): respond to heatingstyrofoam): respond to heating

• Soften and flow when heated, harden Soften and flow when heated, harden when cooled; reversiblewhen cooled; reversible– Over 60 million tons of polyethylene produced Over 60 million tons of polyethylene produced

annually!annually!• Thermosetting plasticsThermosetting plastics (Formica- (Formica-

brand): initially soft, but solid when brand): initially soft, but solid when heated; irreversibleheated; irreversible

Styrofoam, Teflon, silicone, Styrofoam, Teflon, silicone, KevlarKevlar

Condensation PolymersCondensation Polymers

• Combining monomers and splitting Combining monomers and splitting out small molecules (like water)out small molecules (like water)– DemoDemo

•Making nylonMaking nylon

• DemoDemo– Green “snot”Green “snot”

Green “snot”Green “snot”

CopolymersCopolymers

• Polymerization of 2 Polymerization of 2 (or more) diff. (or more) diff. monomersmonomers

• Such as:Such as:– Styrene-butadiene Styrene-butadiene

rubber (SBR)rubber (SBR)• Predominately used Predominately used

for car and light-for car and light-truck tirestruck tires