Organic Chemistry-1. Organic Chemistry is the study of carbon- containing compounds and their properties.

Organic Chemistry-1

Organic Chemistry

• is the study of carbon-containing compounds and their properties.

• Compounds are broken down

into 2 general categories:

• Inorganic Compounds:–Do not contain carbon

Timberlake LecturePLUS 4

Organic Compounds

• Contain significant amounts of carbon.

• are mostly composed of 4 elements:

H, O, N, C “honk”Have covalent bondsHave low melting pointsHave low boiling pointsBurn in air (oxygen) Are soluble in nonpolar solventsForm large molecules

• Exceptions:

–oxides of carbon (CO2, CO)

–carbonates,bicarbonates(NaHCO3,CaCO3)

–cyanides (NaCN, etc)

Origin of organic compounds• Naturally occurring organic

compounds are found in plants, animals, and fossil fuels

• Synthetic organic compounds are derived from fossil fuels or plant material

Carbon:

Carbon is essential to life for several reasons:

–It can form strong stable covalent bonds

–It can form up to 4 chemical bonds

–It can form multiple bonds

Organic Compounds

hydrocarbons (C,H) heteroatomic (O, N, P, S, X, etc.)

aliphatic (fatty) aromatic (pleasant smelling)

alkane alkene alkyne cyclic

C C C CC C

Hydrocarbons:

• Contain C and H only

1.HydrocarbonsC C C C

C CC

C

C

C

C

C

H

H

H

H

H

H

C C C C C

H

H

H

H

H H

H

H

H

H

H

H

Alkanes Alkenes

Alkynes Aromatics

C C C C C

H

H

H

H

H

H

H

H

H

H

C C C C CH

H

H

H

H

H

H

H

1.1.1. AlkanesAlkanes• Hydrocarbon chains where all the bonds Hydrocarbon chains where all the bonds between carbons are SINGLE bondsbetween carbons are SINGLE bonds

• Have 4 bonds to every carbon (C)atom

• Are nonpolar molecules• Saturated• General formula: [CnH2n+2], where n is the

number of C atoms in the compound.• Name uses the ending –Name uses the ending –aneane

12

International

Union of

Pure and

Applied

Chemistry

“eye-you-pac”

colloquially:

Devised following WWII ca. 1946-1950

Nomenclature

Timberlake LecturePLUS 13

IUPAC Names

Name # carbons condensed formulas

Methane 1 CH4

Ethane 2 C2H6

Propane 3 C3H8

Butane 4 C4H10

Pentane 5 C5H12

Hexane 6 C6H14

Timberlake LecturePLUS 14

Structural Formulas

H H

H C H H C H H H

CH4 , methane

• Each pair of electrons is shown as a line in the structural formula.

Timberlake LecturePLUS 15

More Alkanes Condensed Structural Formulas

Ethane

H C C H CH3 CH3

H H H Propane

CH3 CH2 CH3

H H

H H

H H

HHH

C C C

1.1.1.a. Alkyl Groups

• Alkyl group s are obtained when one H is removed from an alkane

Timberlake LecturePLUS 1999 17

Alkyl Groups

H

H C CH3 methyl H H H H C C CH3CH2 ethyl H H

• Shown as R- in general• Name: replace -ane ending of alkane with -yl

ending– CH3 is “methyl” (from methane)–CH2CH3 is “ethyl” (from ethane)–CH2CH2CH3 is “propyl” (from propane)

• CH3Cl methyl chloride

• CH2CH3Br ethyl bromide

1.1.2. Cycloalkanes

• Cycloalkanes are alkanes having carbon atoms that form a ring.

• The two ends of the carbon chain are attached in a ring in a cyclic hydrocarbon

• General formula: CnH2n

• Structure is shown as a regular polygon with the number of vertexes equal to the number of C’s.

• H2C CH2

or • H2C CH2

• cyclobutane• C4H8

Cyclohexane

C

C

C

C

C

C

H

H

H HH

H

H

HH H

H

H

or

to name, prefix the name of the corresponding

open-chain alkane with cyclo-.

Cyclopropane

C3H6

Cyclobutane

C4H8

Cyclopentane

C5H10

Cyclohexane

C6H12

1.1.3.Alkenes:•hydrocarbons that contain a carbon-carbon double bond.

• the simplest member is ethene (ethylene).

No. of Carbon

Atoms in One

Molecule

Alkene Member

Structure of One Molecule

2ethene(C2H4)

3propene

(C3H6)

4butene(C4H8)

HH

CH

HC

H

HC

H

HH C

HC

H

HH C

H

HC

HC

H

HC

•General formula: [CnH2n], where n is the number of C atoms in the compound.•names of alkenes end with –ene.

1.1.4. alkynes:• hydrocarbons containing a carbon-

carbon triple bond.• Acetylene, the simplest alkyne.• “-yne” as a suffix indicates an

alkyne• General formula is CnH2n-2.

Alkynes: CnH2n-2

C2H2 H—C C—H

ethyne (acetylene)

C3H4 CH3CCH

propyne (methylacetylene)

1.2.Aromatic hydrocarbons:• A special class of cyclic unsaturated

hydrocarbons.• Called as “aromatic hydrocarbons”, because

of pleasant odor• Also called as arenes.

–simplest aromatic is benzene

(C6H6)

– or

–Benzene is a six-carbon ring, with alternating double and single bonds

• One derivative of Benzene is called phenylethene, or commonly named STYRENE.

• Foamed styrene is trademarked by Dow Chemicals as “styrofoam”

• Other manufacturers usually just called “foam cups”

CHCH2

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Organic Chemistry- 2.”