Ch. 11: Carbon A Multifarious Element

Why Carbon? Versatility Versatility Single, double, triple bonds Single, double, triple bonds Structural diversity Structural diversity

Short-hand for expressing carbon- based compounds C 4 H 10 : butane C 4 H 10 : butane Structural formula Structural formula Condensed structural formula Condensed structural formula Carbon skeleton formula Carbon skeleton formula C 4 H 8 C 4 H 8 C 4 H 6 C 4 H 6

Isomers Isomers – same composition, diff. structures Isomers – same composition, diff. structures Structural isomers: same # atoms, diff. structures Structural isomers: same # atoms, diff. structures Ethanol (C 2 H 6 O) vs. dimethylether (C 2 H 6 O)

Problems Draw all isomers of C 3 H 8 O. There are 3. Draw all isomers of C 4 H 8 Br 2. There are 9.

Stereoisomers Same formula, diff. orientation Same formula, diff. orientation Two types: Two types: 1) geometric 1) geometric 2) optical isomers 2) optical isomers

Geometric isomers Require double bond! Require double bond! Cis vs. trans Cis vs. trans

Optical isomers Nonsuperimposable mirror images Nonsuperimposable mirror images Called chiral molecules (chirality) Called chiral molecules (chirality) Pairs of chiral molecules = enantiomers Pairs of chiral molecules = enantiomers

Classes of Carbon-Containing Cmpds Hydrocarbons Hydrocarbons Only C & H Only C & H Alkane: C n H 2n+2 Alkane: C n H 2n+2 (Saturated every C-C bond single) (Saturated every C-C bond single) Alkene: C n H 2n (at least one double bond btwn C’s) Alkene: C n H 2n (at least one double bond btwn C’s) (Unsaturated  double, triple bonds) (Unsaturated  double, triple bonds)

Classes of Carbon-Containing Cmpds Alkyne: C n H 2n-2 (at least one triple bond btwn C’s) Alkyne: C n H 2n-2 (at least one triple bond btwn C’s) Cyclohydrocarbons: rings of carbon Cyclohydrocarbons: rings of carbon Aromatic: rings w/pi-bonding Aromatic: rings w/pi-bonding –benzene

Naming Alkanes Suffix: -ane Suffix: -ane Count out longest carbon chain Count 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 Alkanes Hydrocarbon substitution = alkyl groups Hydrocarbon substitution = alkyl groups Meth  methyl, etc. Meth  methyl, etc. Use number, followed by “-”, to designate placement of substituent Use number, followed by “-”, to designate placement of substituent –2-methylpentane If 2 or more of same subs.  di, tri, tetra, etc. If 2 or more of same subs.  di, tri, tetra, etc. –2,3-dimethylpentane If more than one different alkyl group, use alphabetic ordering If more than one different alkyl group, use alphabetic ordering –Butyl precede ethyl precedes methyl 4-ethyl-3-methylheptane 4-ethyl-3-methylheptane In naming hydrocarbons always go with longest carbon-chain In naming hydrocarbons always go with longest carbon-chain

Draw out the following alkanes and rename them, if needed Hexane Hexane 2-methylhexane 2-methylhexane 2,2-diethylpropane 2,2-diethylpropane 4-ethyl-2-methylnonane 4-ethyl-2-methylnonane Now, I’ll draw some and you name them Now, I’ll draw some and you name them

Naming Alkenes, alkynes Start counting carbon chain from lowest carbon containing double/triple bond Start counting carbon chain from lowest carbon containing double/triple bond 1-propene, not 2-propene 1-propene, not 2-propene Use number, followed by “-”, to designate placement of double or triple bond Use number, followed by “-”, to designate placement of double or triple bond –1-butene –2-octyne

Draw the following and if there is isomerism draw both structures and name them 1-hexene 1-hexene 2-hexene 2-hexene 3-heptyne 3-heptyne 2-methyl-3-heptyne 2-methyl-3-heptyne Now, I’ll draw some and you name them Now, I’ll draw some and you name them

Naming Halohydrocarbons Same rules apply Same rules apply –In alphabetical order –Bromine  bromo –chlorine  chloro –fluorine  fluoro –iodine  iodo Ex: 2-chlorobutane Ex: 2-chlorobutane Practice (fix if necessary): Practice (fix if necessary): 3-bromo-2-chloropentane 3-bromo-2-chloropentane 3,3-diiodobutane 3,3-diiodobutane Now, I’ll draw some and you name them Now, I’ll draw some and you name them

Naming Aromatic Cmpds Monosubstitution: Monosubstitution: –Methylbenzene  toluene –Phenol –Aniline Disubstitution: Disubstitution: o- = ortho o- = ortho m- = meta m- = meta p- = para p- = para

Practice Chlorobenzene (does it make a difference where you put the Cl?) Chlorobenzene (does it make a difference where you put the Cl?) Draw all isomers (and name them) of a benzene that has 1 bromine and one fluorine Draw all isomers (and name them) of a benzene that has 1 bromine and one fluorine –Which combinations are disallowed and why?

Other functional groups Functional group = characteristic grouping or arrangement of atoms Functional group = characteristic grouping or arrangement of atoms Alcohols = R-OH Alcohols = R-OH Methanol, ethanol, propanol, etc. Methanol, ethanol, propanol, etc. Structural isomers of alcohols Structural isomers of alcohols 1,2-ethanediol = ethylene glycol 1,2-ethanediol = ethylene glycol

Practice: rename if necessary 1-propanol 1-propanol 2-propanol 2-propanol 3-propanol 3-propanol Now, I’ll draw some and you name them Now, I’ll draw some and you name them

Other functional groups Ether: ROR’ Ether: ROR’ 1) Select the longest carbon chain and name it as the correct alkane. 2) Change the “-yl” ending of the other (shorter) hydrocarbon group to “-oxy” to obtain the alkoxy group name. obtain the alkoxy group name. 3) Combine the two names giving the alkoxy group name first.

Practice Dimethylether Dimethylether Butoxyhexane Butoxyhexane methoxyethane methoxyethane Now, I’ll draw some and you name them Now, I’ll draw some and you name them

Other functional groups Amines Amines RNH 2 RNH 2 Putrescine = 1,4-butanediamine Putrescine = 1,4-butanediamine Cadaverine = 1,5-pentanediamine Cadaverine = 1,5-pentanediamine

Practice Triethylamine Triethylamine Triisopropylamine Triisopropylamine Now, I’ll draw some and you name them Now, I’ll draw some and you name them

Other functional groups Aldehydes Aldehydes RCOH RCOH Start counting the carbon-chain from the C=O Start counting the carbon-chain from the C=O Methanal, butanal, hexanal Methanal, butanal, hexanal Ketones Ketones RCOR’ RCOR’ Start counting the carbon-chain from the C=O Start counting the carbon-chain from the C=O 2-propanone, 3-heptanone 2-propanone, 3-heptanone

Practice Methanal Methanal Hexanal Hexanal 2-pentanone 2-pentanone 4-decanone 4-decanone Now, I’ll draw some and you name them Now, I’ll draw some and you name them

Other functional groups Carboxylic acids Carboxylic acids RCOOH RCOOH Start counting the carbon-chain from the C=O Start counting the carbon-chain from the C=O Methanoic acid, ethanoic acid, etc. Methanoic acid, ethanoic acid, etc. Esters Esters RCOOR’ RCOOR’ Start counting the carbon-chain from the C=O Start counting the carbon-chain from the C=O -OR’  takes on alkyl name -OR’  takes on alkyl name RCO  takes on –oate suffix RCO  takes on –oate suffix Thus, HCOOCH 3  methyl methanoate Thus, HCOOCH 3  methyl methanoate By the way, acetate = ethanoate By the way, acetate = ethanoate

Practice Hexanoic acid Hexanoic acid 2-methylpropanoic acid (give its other name) 2-methylpropanoic acid (give its other name) Hexyl ethanoate Hexyl ethanoate Butyl butanoate Butyl butanoate 3-methylbutyl ethanoate (has a more common name) 3-methylbutyl ethanoate (has a more common name) Now, I’ll draw some and you name them Now, I’ll draw some and you name them

Other functional groups Amides Amides RCONR 2 RCONR 2 Ex: methanamide, ethanamide Ex: methanamide, ethanamide

Polymers Huge molecules with repeating monomers (subunits) Huge molecules with repeating monomers (subunits) Thermoplastics (polyethylene, styrofoam): respond to heating Thermoplastics (polyethylene, styrofoam): respond to heating Soften and flow when heated, harden when cooled; reversible Soften and flow when heated, harden when cooled; reversible –Over 60 million tons of polyethylene produced annually! Thermosetting plastics (Formica-brand): initially soft, but solid when heated; irreversible Thermosetting plastics (Formica-brand): initially soft, but solid when heated; irreversible

Styrofoam, Teflon, silicone, Kevlar

Condensation Polymers Combining monomers and splitting out small molecules (like water) Combining monomers and splitting out small molecules (like water) –Demo Making nylon Making nylon Demo Demo –Green “snot”

Green “snot”

Copolymers Polymerization of 2 (or more) diff. monomers Polymerization of 2 (or more) diff. monomers Such as: Such as: –Styrene-butadiene rubber (SBR) Predominately used for car and light-truck tires Predominately used for car and light-truck tires