Organic Chemistry Organic Chemistry ((the study of organic compounds, those

containing the element carbon)

CARBON

• Of the millions of known compounds in our world, 95% have a single element in common – CARBON.

• What is so special about carbon?

1. Our bodies are made up of organic comp’ds

We study organic compounds because they are very important to our lives.

• Most of the energy to run autos, trains and aircrafts, to heat our homes and offices, and to operate electrical equipment come from organic comp’ds.

• Organic compd’s in naturally occurring and synthetic medicines—aspirin, penicillin, anesthetics etc—relieve pain and illness.

• The active ingredients in soaps, detergents, polishes, cosmetics, deodorants, and shampoos are organic comp’ds.

• Materials for manufacturing artificial body parts, such as hip and knee prostheses, heart valves, and dentures, are organic comp’ds

• Synthetic plastics, textiles, and rubber are organic comp’ds. Our clothing are made from organic compd’s.

C lies at top of Grp 4A and is relatively small element.

The Position of Carbon in the Periodic TableThe Position of Carbon in the Periodic Table

Carbon

• Smallest member, and only nonmetal, of Group 4

• Forms 4 covalent bonds

• Forms single, double, and triple bonds

• Bonds to itself, forming rings

“I am Carbon and I am Special”

1. I can form strong and short C-C bonds.

2. I gladly form carbon-carbon double bonds (C=C), and I can even form carbon-carbon triple bonds (C≡C).

3. I have no problem bonding to other elements (H, O, N, S, etc.–I love them all). Given where I am in the periodic table, I typically form four bonds, except in carbon monoxide (CO).

You can spend your whole life learning about me!

Some bonding possibilities for C

I Can Amaze You With Diversity

Consider the number of compounds possible (23) from just 4 single bonded C atoms, one O atom, the required H atoms

These are called structural isomersstructural isomers –compounds with the same chemical formulas, but different ways of connecting the atoms together to form different functional groups, or different compounds with completely different chemical and physical properties.

Two isomers of butane (C4H10)

Fig. 10.3a n-butane

Fig. 10.3b iso-butane

Molecular & Structural FormulasMolecular & Structural Formulas

• Molecular Formula - formula of the comp’d showing the number of atoms of each element in a molecule of the compound.

Examples: CH3COOH, C2H4, etc.

• Structural Formula -- formula showing how various atoms in molecule are bonded together.

Examples: See previous slide

Certain Parts of Me Make Me Behave in Certain Predictable Ways

Functional Groups – atoms or specific groups of atoms in a molecule that impart specific chemical and physical properties to the molecule.

The secret to learning organic chemistry.

As the periodic table is to inorganic chemistry, functionalgroups are the easy way to learn organic chemistry.

Four of the Functional Groups

C O H

Alcohol

Alcohol group - Hydroxyl group

..

..Ether group

C O C....

Ether

Carboxylic acid group Ester group

.. ..

C O C

O

..

..

..

C O H

O

Carboxyl

..

..

..Ester

Structures & Classes of Structures & Classes of Hydrocarbons (HCs)Hydrocarbons (HCs)

There are four families of hydrocarbons: alkanes, alkenes, alkynes, and aromatics.

SaturationSaturation

• Alkanes are saturated; they contain the maximum number of hydrogen atoms per carbon atom.

• Alkenes and alkynes are unsaturated. They contain at least one double or triple bond, respectively. They have fewer hydrogen atoms per carbon atom than alkanes.

Hydrocarbons (HCs) C + H

Saturated hydrocarbonsSaturated hydrocarbonsAlkanes: general formula is CnH2n+2 (all C-C bonds)

Cycloalkanes: general formula is CnH2n

(n is a positive whole number for all HCs)

Unsaturated hydrocarbonsUnsaturated hydrocarbons Alkenes: general formula is CnH2n (C=C bonds)

Alkynes: general formula is CnH2n–2 (CC bonds)

Aromatics: usually contain one or more rings of six C atoms called benzene rings

(n is a positive whole number for all HCs)

Naming

• Straight chain alkanes are named with a base name depending on the number of atoms in the carbon chain and the suffix –ane.

The most important property of the alkanes is their flammability, the combustion reaction between oxygen and the alkane producing

carbon dioxide and water.

More on Functional More on Functional GroupsGroups

Functionalized Hydrocarbons• Basic hydrocarbon structures form a foundation for a

major grouping of organic compounds.

• Contain additional atoms or groups of atoms

• Insertion of functional groups to a hydrocarbon dramatically alters its properties.

Representing Functionality

Compounds containing the same functional group are called a family.

Generic symbolism is R-FG where R is the hydrocarbon part of the molecule and FG is the functional group.

R-OH symbolizes the alcohols.

Functional groups help organize and classify organic compounds.

Chlorinated Hydrocarbons

• Found in pesticides, solvents, refrigerant liquids• One or more chlorine atoms substitute for one or

more hydrogen atoms• Lower flammability and reactivity than hydrocarbons

CFCs

• Chlorofluorocarbons are a subfamily of chlorinated hydrocarbons.

• Chemically stable . . .

• Until they reach the high-energy sunlight in the upper atmosphere

• Ozone destruction led to bans.

Alcohols

• General formula: R-OH

• Additional of the –OH makes alcohols polar.

• Increased intermolecular attractive forces makes alcohols liquids.

• Naming involves modifying the hydrocarbon name with an ending of –ol.

Ethanol• Alcoholic beverages• Gasoline additive• Sugar fermentation

• CNS depressant• Adverse health effects

Other Alcohols

• Isopropyl alcohol is commonly known as rubbing alcohol. • Methanol is toxic to

the human liver.• Ethanol is

administered as an antidote.

Aldehydes and Ketones• Commonly found in pleasant flavors and aromas• Contain the carbonyl group: Carbon double

bonded to an oxygen atom

Formulas

• Aldehydes– General formula:

RCHO, includes carbonyl group

– Named according to length carbon chain with the ending of –al or –aldehyde

– Methanal or formaldehyde

• Preservation of biological specimens

Formulas

• Ketones– Similar to aldehydes

but have two R groups with the carbonyl

– Names end in –one

– Acetone is the simplest ketone.

• Nail polish removal

Carboxylic Acids

• Commonly found in sour foods

• General formula: RCOOH

• One of these oxygen atoms is bonded as a carbonyl group, as in aldehydes and ketones.

Esters

• Esters have pleasant odors.• General formula: RCOOR• Named according to the relevant R

groups and ending with –ate

Ethers

• Ethers contain the functional group –O-• General formula: ROR• Named according to the two R groups

and given the ending ether

• Formerly used as an anesthetic

Amines• Amines are organic compounds that

contain nitrogen.

• General formula: NR3

• Notable for disagreeable odors• Named for R groups present and

ending in –amine