Organic Chemistry

Organic Compounds

• Def: Cmpds that are contain mostly carbon and hydrogen (millions)

Ex) plastics, foods, fabrics • Inorganic cmpds – derived from nonliving

things

General Characteristics of Organic Cmpds

• Major diff in organic vs inorganic• inorganic – formed from ionic, covalent, or coordinate

covalent bonds• Organic – formed from covalent bonds • Generally non-polar

insoluble in H2O

soluble in nonpolar solvents (hexanes, benzene)

• Nonelectrolytes (no ions dissociate)

General Characteristics of Organic Cmpds

• Weak intermolecular forces of attraction– London Dispersion forces only (low MP and BP,

high vapor pressure)

• Slow to react (strong covalent bonds)• Major natural resource

Ex) petroleum, coal, natural gas

Structural formulas

• Def: show bonding arrangement of atoms• Carbon has 4 bonding sites• Draw Lewis dot diagram

Methane

Structural formulas

• The 4 bonds of carbon are pushed to the 4 corners of a tetrahedron

• Carbon forms so many diff cmpds because it can bond to itself, by forming– single bonds– double bonds– triple bonds

Saturated compounds

• Def: organic compounds in which all carbon to carbon bonds are single bonds

Ex) ethane propane

Unsaturated Cmpds

• Def: organic cmpds in which at least one Carbon to Carbon bonds is a double or triple bond

Ex) ethene propene

Ethyne propyne

Homologous Series of Hydrocarbons

• Homologous series – grp of organic cmpds that have similar properties and related structures

– hydrocarbons – cmpds containing only carbon and hydrogen

Alkane series

• Def: grp of hydrocarbons which contain carbon atoms linked by single bonds

• Alkanes are saturated cmpds•

Alkane series

• Naming: prefixes are used to relate the # of carbons in the cmpd

• (Table P)meth - hex- eth - hept - prop - oct- but - non - pent - dec-

• - all end in suffix -ane

• Pentane (C5H12)

• General formula (CnH2n+2)

Isomers

• cmpds that have the same molecular formula, but different structural formulas

• isomers represent different compounds with different chem and physical properties

Isomers

• Isomerism begins with butane, C4H10

Naming isomers

• system is based on the longest continuous chain of carbon atoms

• number the longest carbon chain so that the attached group gets the lowest possible #

• branch is named using the # of Carbons prefix,• followed by – yl• name ends in longest carbon chain name

2 methyl propane

Practice: Name the following

Write a structural formula for the following

4-ethyl decane

If a halogen is attached to the C chain, use the following prefixes

Cl – chloro

F – flouro

Br – bromo

I - iodo• number the halogen

Practice

1 – chloropropane 2 – chloropropane 1,2 – dibromopropane 1,1 – dichlorobutane

Alkenes

• a homologous series of unsaturated hydrocarbons which contain one double bond

• General Formula: CnH2n

• prefixes remain same• end in –ene

Alkenes

propene

Isomers of alkenes

1- butene, C4H8 2-butene

Alkynes

• unsaturated hydrocarbons that contain at one triple bond

• General Formula: CnH2n-2

• - end in -yne

• Isomers of alkynes, named for the position of the triple bond

Alkynes

1-butyne, C4H6 2- butyne

Other Organic Compounds (table R)

• Functional Groups• atoms or groups of atoms that give certain

characteristics to an organic molecule (determine how a molecule will react)

Halides

• Def: cmpds in which a halogen atom (F, Cl, Br, or I) replaces a hydrogen on from an alkane.

• on long carbon chains use a number to note the location of the halogen on the carbon chain

Ex) CH3Cl CH3CH2Br

Chloromethane Bromoethane

Alcohols

• contain the functional grp: -OH• (not a hydroxide ion)• ex) R – OH• R represents some carbon chain • Naming: named for the parent alkane chain,

replace last e with -ol

Draw the following:

CH3OH – methanol CH3CH2OH – ethanol

3- pentanol

Ethers

• contain functional grp C - O – C

• General formula: R – O – R • Where the R grps do not have to be the same

• Naming: the RO in the group is the alkoxy group

CH3OCH3 CH3CH2OCH3

Diethyl ether

Organic Acids (carboxylic acids)

• Contain the functional grp: -COOH• Draw actual orientation.

• General formula: R- COOH• Name: name for # of Carbons use alkane

name drop –e and and add – oic acid.

HCOOH CH3COOH

propanoic acid

Amines (considered derivatives of ammonia)

– Functional Grp : - NH2

– General Formula: R – NH2

• R2 – NH

• R3 – N– Naming: name the alkane group to which the

amine is attached• drop the –e ending and add amine

CH3NH2 CH3CH2NH2

2-propanamine

Aldehydes

–contains the functional group:

O R – C – H

– Name: use alkane name for the carbon chain (including carbon attached to the Oxygen) • drop –e and add – al

=

methanal pentanal

ethanal

Ketones

– contain the functional group:

– Name: use alkane name for longest carbon chain• drop –e ending, add - one • number the carbon in which the doublely bonded

oxygen is located

butanone propanone (acetone) 2-pentanone

Amides

• contain the functional grp: O

R- C or RCONH2

NH2

Naming: name the longest carbon chain as you would an alkane drop the –e and add amide

=

_

ethanamide N, N dimethylamide

- N’s denote the

methyl grps attached to the

nitrogens

Do Now:

Identify whether the following are saturated or unsaturated:

C5H10 C4H10

C3H4 C7H16

Esters• contain the functional grp:

OR - C O - R

• Name: names are derived from the alcohol and the acid from which it

is formedportion from the alcohol comes 1st (this is R’)portion from the acid comes 2nd using the alkane name, dropping the –e and adding -

oate

=

_

ethyl pentanoate. ethyl ethanoate

Amino Acids

• Contain both the amino and the organic acid functional group.

• Do not need to name

Organic Reactions

Combustion Reactions of Alkanes

• C3H8(g) + 5O2(g) ----> 3CO2(g) + 4HOH(g)

• 2C4H10(g) + 13 O2(g) ----> 8CO2(g) + 10HOH(g)

Addition Reactions

- The addition of one or more atoms or groups of atoms across a double or triple bond (unsaturated hydrocarbons)

CH CHCH H CH CH CHcatalyst2 3 2 3 2 3

propene propane

Halogenation

CH2=CHCH2CH2CH3 + Br2 ---> CH2BrCHBrCH2CH2CH3

1-pentene 1,2-dibromopentane

Hydrogen AdditionHydrogenation

C2H4(g) + H2(g) ---> C2H6(g)

unsaturated saturated

Substitution Reactions for Alkanes

•Primarily where halogen atoms replace hydrogen atoms on saturated hydrocarbons.

CHCl Cl CCl HClh3 2 4

Esterification

Acid + Alcohol → Ester + water

+ CH3COOH

Do Now: Identify the type of reaction that occurs between the following

compounds and name the products formed.

Butanol + Butanoic acid →

Saponification Reaction:

Fat + strong base Soap + Glycerol

NaOHKOH

O HC17H35-C-O-C-H + NaOH

OC17H35-C-O-C-H + NaOH

OC17H35-C-O-C-H + NaOH

H

Fat Lye (Triglyceride)

O H

C17H35-C-ONa H-C-OH

OC17H35-C-ONa + H-C-OH

OC17H35-C-ONa H-C-OH

H

Soap! Glycerol

How does it happen?? O• Break the ester linkages C – O- by

hydrolyzing the bonds between the carbon backbone and the fatty acid chains.

• (Reversal of esterification reaction)

• Form the sodium salt of a fatty acid (soap) and a trihydroxy alcohol (glycerol).

Fermentation

zymaseC6H12O6 2 C2H5OH + 2 CO2

The basic fermentation reaction:

Polymers

• . . . are large, usually chainlike molecules that are built from small molecules called monomers.

• Monomer PolymerEthylene PolyethyleneVinyl chloride Polyvinyl

chlorideTetrafluoroethylene Teflon

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)

Addition Polymerization

Condensation Polymerization