ORGANIC CHEMISTRY

Organic Chemistry Study of carbon and carbon compounds Organic compounds contain carbon atoms which covalently bond to each other in chains, rings, and networks to form a variety of structures

General Characteristics of Organic Compounds Nonpolar Soluble in nonpolar solvents / insoluble in polar solvents (water) “Like dissolves Like” Poor conductors of heat and electricity –Exception: aqueous organic acids conduct Low melting and boiling points React slower than inorganic compounds –High activation energies

Molecular Formulas –Indicates the kind and number of atoms of each element in the compound –Example: C 2 H 6 Empirical Formulas –Reduced formula, in lowest terms –Example: What is the empirical formula for C 4 H 10

Structural Formulas –Attempts to show the bonding patterns and approximate shapes –Ex: Condensed Structural Formulas –Shows the connections without showing the shape and bonds –Ex:

Bonding Carbon- has 4 valence electrons, needs 4 more, forms 4 bonds Oxygen – has 6 valence electrons, needs 2 more, forms 2 bonds Hydrogen – has 1 valence electron, needs 1 more, forms 1 bond Halogens (group 17) – has 7 valence electrons, needs 1 more, forms 1 bond

Homologous Series (Families) Group of related compound in which each member has one more group –Ex: CH 3 CH 2 CH 3 and CH 3 CH 2 CH 2 CH 3 Members of a group will have similar structures and properties As the members of a series increase in mass, their boiling (and melting) points increase – due to increased intermolecular forces

Hydrocarbons Organic compounds that contain only CARBON and HYDROGEN ALKANES... SINGLE bonds between Carbons Saturated hydrocarbon C x H 2x+2 ONE TRIPLE bond between two Carbons Unsaturated Hydrocarbon ONE DOUBLE bond between two Carbons Unsaturated hydrocarbon C x H 2x C x H 2x-2 ALKYNES... ALKENES... Family Name

…counting the CARBONS PREFIXES

ALKANES Contain all single bonds Naming: carbon prefix + -ane Example: Ethane Octane Butane C 4 H 10

ALKENES Contain 1 double bond Naming: carbon prefix + -ene –A number is used in front to indicate the location of the double bond –If a number is not indicated the double bond comes after the 1 st carbon Example: 2-Pentene

Diene Contains 2 double bonds Naming: location-carbon prefix-diene Example: 1,3-pentadiene Propadiene C 3 H 4

ALKYNES Contains 1 triple bond Naming: carbon prefix + -yne Example: Ethyne Ethyne Propyne

Saturated Compounds – contains all single carbon-carbon bonds Unsaturated Compounds – contains at least multiple carbon-carbon bond

Branched Hydrocarbons Contain 1 or more branches off the main chain Methyl group on carbon 4 4-methyl-ocatane

Naming Branched Hydrocarbons Find the longest continuous chain, name it To name the branches: number of carbons + “-yl” –Examples: CH 3 = methyl CH 2 CH 3 = ethyl The location of the alkyl (branched group) is indicated –If there is more than one of the same branch, use prefixes (di, tri, tetra, …) –The carbon chain must be numbered from the end that will give the lowest numbers for the branches Example: 2, 2, 3 – trimethyl pentane

SAME…BUT DIFFERENT 2 CARBONS 6 HYDROGENS 1 OXYGEN ETHANOL a primary alcohol DIMETHYL ETHER C 2 H 5 OH CH 3 OCH 3 Same – number and type of atoms Different – structure and name  Have different physical and chemical properties

GROUPS and COMPOUNDS

Functional Group: halogen (group 17 element) Name: location-halide-carbon chain Examples: 1. 2-bromobutane 2. 1,3 - dichloropentane

ALCOHOLS Functional Group: -OH No more than one –OH group can be attached to any one carbon The carbon to which the –OH group is attached must have all single bonds Alcohols are not bases (do not ionize in water) Name: hydrocarbon name, replace the final –e with –ol Examples: 1.Methanol 2.2-Propanol

Types of Alcohols Monohydroxy – contain 1 –OH group –Primary –Secondary –Tertiary Dihydroxy (Diol) – contain 2 –OH groups Trihydroxy (Triol) – contain 3 –OH groups

Primary Alcohols Contain 1 –OH group -OH group is attached to the end of the chain Examples: 1.Ethanol 2.Propanol

H SECONDARY ALCOHOL R-C-R O H -OH GROUP ON SECOND CARBON FROM RIGHT 4 CARBONS Contain 1 –OH group Carbon that is attached to the –OH group is attached to 2 other carbon atoms 2-Butanol

R TERTIARY ALCOHOL R-C-R O H Methyl group -OH GROUP ON SECOND CARBON FROM RIGHT 2METHYL,2-BUTANOL 4 CARBONS in sequence Ethyl group Methyl group Contain 1 –OH group Carbon attached to the –OH group is attached to three other carbon atoms

2 -OH groups are present 1,2 ethanediol

3 -OH groups are present 1,2,3 propanetriol

CH 3 COOH Functional Group = -COOH Name: Hydrocarbon name, drop the final “e” and replace it with “–oic” followed by the word “acid” Examples: 1. Ethanoic Acid 2. Butanoic Acid

ethanal 2 carbons alkane aldehyde CH 3 CHO Functional Group: -CHO Name: drop the final “e” and add “-al” Propanal

Propanone CH 3 COCH 3 Functional Group: -CO- Name: Hydrocarbon name, drop the final “e”, add “one” 2-Butanone

Functional group: -O- (chain-O-chain) Name: 1. Name each hydrocarbon chain – drop the ending add “yl” 2. Add “ether” to the end diethyl ether C2H5OC2H5C2H5OC2H5 Ethyl methyl ether

Functional Group: -COOR Formed from a dehydration reaction of an alcohol and an acid Fruity odor Name: Name each hydrocarbon chain –The part with the –CO gets the “-oate” ending –The other part gets the “-yl” ending

Ester Examples Ethyl Methanoate Ethyl Ethanoate HCOOC 2 H 5

ethanamine C 2 H 5 NH 2 Functional Group: NH 2 Name the chain, add “amine” to the end

Butanamide C 3 H 7 CONH 2 Propanamide Functional Group: R-CONH 2 Name: Name the chain, add “amide” to the end

Functional Groups: -NH 2 and –COOH

Just like an alcohol, but –SH instead of – OH Example: Methyl Thiol (CH 3 SH)

ADDITION SUBSTITUTION ESTERIFICATION SAPONIFICATION POLYMERIZATION COMBUSTION FERMENTATION

C2H6C2H6 Cl 2 C 2 H 4 Cl 2 H2H2 Something takes the place of something else Starts with a saturated hydrocarbon

C2H4C2H4 Cl 2 C 2 H 4 Cl 2 Start with an unsaturated hydrocarbon Break the double (or triple) bond Add in an atom (or group)

ORGANIC ACID + ALCOHOL H 2 SO 4 ESTER + WATER C 2 H 5 COOH CH 3 OH C 2 H 5 COOCH 3 H2OH2O Concentrated H 2 SO 4 acts as a dehydrating agent

FAT (glycerol ester) Strong base (NaOH or KOH) SOAPglycerol (trihydroxy alcohol) 1,2,3 propane triol Reverse of esterification, carried out in the presence of a base See p.169 for an example

GLUCOSE ZYMASE ETHANOL CARBON DIOXIDE C 6 H 12 O 6 C 2 H 5 OHCO 2

Hydrocarbon + O 2 CO 2 + H 2 O Exothermic Example: C 2 H 6 + O 2

Poly...poly...poly…poly...poly...polymeri zation Chains of small units make up a MACROMOLECULE Examples: Plastics, proteins

Condensation Polymerization Bonding of monomers by a dehydration reaction –OH groups of adjacent alcohols react, water is removed, the 2 molecules are connected by the remaining O Examples: Nylon, Protein, Polyester

Addition Polymerization Bonding of monomers of unsaturated compounds by “opening” a multiple bond in the carbon chain Example: polyethylene and many plastics n C2H4n C2H4 (C 2 H 4 ) n