Organic Chemistry and Biochemistry The study of carbon-containing compounds and their properties. The vast majority of organic compounds contain chains and rings of carbon atoms. The study of the chemistry of living things.

Hydrocarbons... compounds composed of carbon and hydrogen. Saturated: carbon-carbon bonds are all single - alkanes [C n H 2n+2 ]

Hydrocarbons (continued) Unsaturated: contains carbon-carbon multiple bonds.

24.1 Classification of Hydrocarbons

24.2 Alkanes Alkanes have the general formula C n H 2n+2 where n = 1,2,3,… only single covalent bonds saturated hydrocarbons because they contain the maximum number of hydrogen atoms that can bond with the number of carbon atoms in the molecule CH 4 C2H6C2H6 C3H8C3H8 methaneethanepropane

Rules for Naming Alkanes 1. For alkanes beyond butane, add -ane to the Greek root for the number of carbons. C-C-C-C-C-C = hexane 2. Alkyl substituents: drop the -ane and add -yl. -C 2 H 5 is ethyl

Rules for Naming Alkanes 3.Positions of substituent groups are specified by numbering the longest chain sequentially. C  C-C-C-C-C-C 3-methylhexane 4.Location and name are followed by root alkane name. Substituents in alphabetical order and use di-, tri-, etc.

24.2 Structural isomers are molecules that have the same molecular formula but different structures

How many structural isomers does pentane, C 5 H 12, have? CCCC C HHHHH H HHHHH H CCC C HCH 3 HH H HHHH H CC C H H H HH H n-pentane 2-methylbutane 2,2-dimethylpropane 24.2

Alkane Nomenclature 1.The parent name of the hydrocarbon is that given to the longest continuous chain of carbon atoms in the molecule. CH 3 CH 2 CHCH 2 CH methylheptane 2.An alkane less one hydrogen atom is an alkyl group. CH 4 CH 3 methane methyl

24.2 Alkane Nomenclature

24.2 Alkane Nomenclature 3.When one or more hydrogen atoms are replaced by other groups, the name of the compound must indicate the locations of carbon atoms where replacements are made. Number in the direction that gives the smaller numbers for the locations of the branches. CH 3 CHCH 2 CH methylpentane CH 3 CH 2 CHCH methylpentane

24.2 Alkane Nomenclature 4.Use prefixes di-, tri-, tetra-, when there is more than one alkyl branch of the same kind. CH 3 CH CH 2 CH ,3-dimethylhexane CH 3 CHCCH 2 CH ,3-dimethylhexane

24.2 Alkane Nomenclature 5.Use previous rules for other types of substituents. CH 3 CH CH 3 Br 1234 NO 2 2-bromo-3-nitrobutane CH 2 CHCH 3 Br 1234 NO 2 1-bromo-3-nitrobutane

What is the IUPAC name of the following compound? CH 3 CHCH 2 CHCH 2 CH 3 C2H5C2H5 CH 2 CH 3 2-methyl-4-ethyloctane What is the structure of 2-ethyl-4-methylhexane? CH 3 CHCH 2 CHCH 2 CH 3 C2H5C2H5

24.2 Alkane Reactions CH 4 (g) + 2O 2 (g) CO 2 (g) + 2H 2 O (l)  H 0 = kJ Combustion Halogenation CH 4 (g) + Cl 2 (g) CH 3 Cl (g) + HCl (g) light Cl 2 + energy Cl + Cl Cl + CH H H H CH H H + HCl CH H H + Cl Cl CCl H H H + Cl

Substitution Reactions Primarily where halogen atoms replace hydrogen atoms.

24.2 achiralchiral

24.2 Cycloalkanes Alkanes whose carbon atoms are joined in rings are called cycloalkanes. They have the general formula C n H 2n where n = 3,4,…

Alkenes and Alkynes Alkenes: hydrocarbons that contain a carbon- carbon double bond. [C n H 2n ] C  C=C propene Alkynes: hydrocarbons containing a carbon- carbon triple bond. C  C  C  C  C 2-pentyne

Nomenclature for Alkenes 1.Root hydrocarbon name ends in -ene C 2 H 4 is ethene 2.With more than 3 carbons, double bond is indicated by the lowest numbered carbon atom in the bond. C=C  C  C is 1-butene

24.2 Alkenes Alkenes have the general formula C n H 2n where n = 2,3,… contain at least one carbon-carbon double bond also called olefins CH 2 CHCH 2 CH 3 1-butene CH 3 CH CH 3 2-butene CC Cl HH CC H H cis-dichloroethylenetrans-dichloroethylene

Addition Reactions...in which (weaker)  bonds are broken and new (stronger)  bonds are formed to atoms being added.

24.2 Alkene Reactions Cracking Addition Reactions CH 2 CH 2 (g) + HBr (g) CH 3 CH 2 Br (g) CH 2 CH 2 (g) + Br 2 (g) CH 2 Br CH 2 Br (g) C 2 H 6 (g) CH 2 CH 2 (g) + H 2 (g) Pt catalyst

24.2 Alkynes Alkynes have the general formula C n H 2n-2 where n = 2,3,4,… contain at least one carbon-carbon triple bond 1-butyne2-butyne CH CCH 2 CH 3 CC Production of acetylene CaC 2 (s) + 2H 2 O (l) C 2 H 2 (g) + Ca(OH) 2 (aq)

24.2 Alkyne Reactions Addition Reactions Hydrogenation CH CH (g) + H 2 (g) CH 2 CH 2 (g) CH CH (g) + HBr (g) CH 2 CHBr (g) CH CH (g) + Br 2 (g) CHBr CHBr (g) CH CH (g) + 2Br 2 (g) CHBr 2 CHBr 2 (g)

24.3 Aromatic Hydrocarbons C C C CC C H H H H H H C C C CC C H H H H H H

24.3 Aromatic Compound Nomenclature CH 2 CH 3 ethylbenzene Cl chlorobenzene NH 2 aminobenzene NO 2 nitrobenzene Br 1,2-dibromobenzene Br 1,3-dibromobenzene

Aromatic Hydrocarbons A special class of cyclic unsaturated hydrocarbons. + Cl 2 + HCl benzeneChlorobenzene

24.3 Aromatic Compound Reactions H H H H H H Br H H H H H + HBr+ Br 2 FeBr 3 catalyst H H H H H H CH 2 CH 3 H H H H H + HCl+ CH 3 CH 2 Cl AlCl 3 catalyst Substitution reaction

24.3 Polycyclic Aromatic Hydrocarbons

The Common Functional Groups ClassGeneral Formula HalohydrocarbonsR  X AlcoholsR  OH EthersR  O  R Aldehydes

The Common Functional Groups ClassGeneral Formula Ketones Carboxylic Acids Esters AminesR  NH 2

24.4 Functional Group Chemistry Alcohols contain the hydroxyl functional group and have the general formula R-OH.

C 6 H 12 O 6 (aq) 2CH 3 CH 2 OH (aq) + 2CO 2 (g) enzyme CH 2 CH 2 (g) + H 2 O (g) CH 3 CH 2 OH (g) H 2 SO 4 Biological production of ethanol Commercial production of ethanol Metabolic oxidation of ethanol CH 3 CH 2 OH CH 3 CHO + H 2 alcohol dehydrogenase 24.4

Functional Group Chemistry Ethers have the general formula R-O-R’. CH 3 OH + HOCH 3 CH 3 OCH 3 + H 2 O H 2 SO 4 catalyst Condensation Reaction

24.4 Functional Group Chemistry Aldehydes and ketones contain the carbonyl ( ) functional group. O C R C H O aldehydes have the general formulaR C R’ O ketones have the general formulaH C H O H C O CH 3 C O H3CH3C formaldehydeacetaldehydeacetone

24.4 Functional Group Chemistry Carboxylic acids contain the carboxyl ( -COOH ) functional group.

24.4 Functional Group Chemistry Esters have the general formula R’COOR, where R is a hydrocarbon group. CH 3 COOH + HOCH 2 CH 3 CH 3 C O CH 2 CH 3 + H 2 O O ethyl acetate

24.4 Functional Group Chemistry Amines are organic bases with the general formula R 3 N. CH 3 NH 2 + H 2 O RNH OH - CH 3 CH 2 NH 2 + HCl CH 3 CH 2 NH 3 + Cl -

24.4

Polymers...are large, usually chainlike molecules that are built from small molecules called monomers. MonomerPolymer EthylenePolyethylene Vinyl chloridePolyvinyl chloride TetrafluoroethyleneTeflon

Types of Polymerization Addition Polymerization: monomers “add together” to form the polymer, with no other products. (Teflon) Condensation Polymerization: A small molecule, such as water, is formed for each extension of the polymer chain. (Nylon)

Proteins Natural polymers made up of  -amino acids (molecular weight from  6000 to >1,000,000 g/mol). Fibrous Proteins: provide structural integrity and strength to muscle, hair and cartilage.

 -Amino Acids  NH 2 always attached to the  -carbon (the carbon attached to  COOH) C =  -carbon

Bonding in  -Amino Acids + H 2 O  A peptide linkage There are 20 amino acids commonly found in proteins.