Chapter 19 & 20 - Organic Chemistry

1

Organic Compounds

An organic compound

• _{is a compound with one or more C atoms} • _{has many H atoms}

2

Organic Compounds

Typical organic compounds

• _{contain carbon}

• _{have covalent bonds} • _{have low melting points} • _{have low boiling points} • _{are flammable}

3

4

Organic Molecules

In organic molecules with more carbon atoms,

• _{valence electrons are shared}

• _{covalent bonds form between C atoms}

• _{covalent bonds form between C and H atoms}

H H H H • • • •

H







• • • •

Carbon always has 4 bonds

C C C C C C C

7

Properties of Alkanes

Alkanes

• _{are nonpolar}

• _{are less dense than water}

• _{with 1-4 carbon atoms are gases}

• with 5-8 carbon atoms are liquids at room temperature

• with 9-17 carbon atoms are liquids such as

kerosene, diesel, and jet fuel

Properties of Alkanes

• _{Methane (CH4), propane (C3H8),}

and butane(C₄H₁₀) are all used as fuels.

• _{Cyclopropane (C}

3H6) is a safe,

effective, and fast acting anesthetic.

• _{Pyrethrins are cyclopropane}

derivatives found in the

Properties of Alkanes

•

Liquid alkanes (gasoline)

dissolve and wash away

oils.

•

Solid alkanes make up the

waxy coating on fruits and

vegetables. They are also

applied to the skin as

10

Structural Formulas

Alkanes are written with structural formulas that are

• _{expanded to show each bond}

• _{condensed to show each carbon atom and its}

11

Drawing Structures for Butane

In the expanded structure formula, each bond from the C atom to the attached H atoms is shown.

Representing Organic Compounds

•

Molecular Formula -- C

H

•

_{Complete structural formula –}

•

_{Condensed structural formula –}

•

_{Line formula}

•

_{***PREFERRED**}

C C C

C HH H H H H H H H H or

CH3CH2CH2CH3 CH3CHCH3

CH3

or

Isomers - Compounds that have

the same molecular formula but

different structural formulas.

CH₃ CH₃

H₃C CH

CH₃ CH₃

CH CH₃

CH₃ CH₂

CH₂ CH₃

CH CH₂ CH₂ CH₃

CH₃ CH_CH2

2 CH₂ CH₂ CH₂ CH₂ CH₃

H₃C

CH₂ CH₃

CH₂ CH₃ C

CH₂ CH₃

Isomers - Compounds that have

the same molecular formula but

CH₃CH₂CH₂CH₂CH₂CH₂CH₃ CH₃CHCH₂CH₂CH₂CH₃ CH₃

CH₃CH₂CHCH₂CH₂CH₃ CH₃

CH₃

CH₃CHCH₂CHCH₃

CH₃ CH₃

CH₃CCH₂CH₂CH₃ CH₃

CH₃

CH₃CHCHCH₂CH₃ CH₃

CH₃

CH₃CH₂CCH₂CH₃ CH₃

CH₃CH₂CHCH₂CH₃ CH₂

CH₃

CH₃ CH CH₃ CH₃ CH₃

C CH₃

Isomers of Heptane

n-heptane _{2-methylhexane}

3-methylhexane

2,4-dimethylpentane _{2,3-dimethylpentane 2,2-dimethylpentane}

17

Functional groups are

• _{a characteristic feature of organic molecules}

that behave in a predictable way

• _{composed of an atom or group of atoms} • _{replace H on a carbon chain}

• _{a way to classify families of organic}

compounds

Functional Groups in Organic

Compounds

•

_Hydrocarbons

•

Alcohols (“-ol”) and Ethers

•

Aldehydes (“-al”) and Ketones (“-one”)

•

_{Carboxylic acids (“-oic acid”) and Esters}

•

_{Amines and Amides}

Unsaturated Hydrocarbons

20

Alkenes, Alkynes, and Aromatic

Compounds

• _{Alkenes contain a double}

bond between adjacent carbon atoms.

• _{Alkynes contain a triple}

bond between adjacent carbon atoms.

• _{Aromatic compounds}

Alcohols and Ethers

• Alcohol

• contains the

hydroxyl (-OH)

functional group.

• General formula R-OH

• Ether

• an oxygen atom is bonded to two

carbon atoms.

• General formula R-O-R

Methanol CH₃OH

Ethanol CH₃CH₂OH

Dimethyl ether CH₃OCH₃

Aldehydes and Ketones

•

_{Contain a}

_carbonyl

group

•

_Aldehydes

– _{Carbonyl attached to}

at least 1 hydrogen

•

_Ketones

– _{No hydrogen attached}

Aldehydes and Ketones

C CH₃

CH₃CH₂ O

Carboxylic Acids and Esters

•

_{Contain a}

_carboxyl

group

•

_{Carboxylic acid}

– _{Oxygen attached to H}

•

_Esters

– _{Carbon (R) group}

attached to H O C O

O

C O H

O

Carboxylic Acids and Esters

C O CH₃

CH₃CH₂ O

Amines and Amides

•

_{Contain nitrogen}

•

_Amines

•

_Amides

– _{Carbonyl attached to a}

nitrogen (like carboxylic acid) H R₁ N R₂ O

Amines and Amides

H

H N CH₃

H

H N CH₂CH₃

H O C NH₂

CH₃ O C NH₂

CH₃CH₂ O

C NH₂ Methyl amine

Ethyl amine

Methanamide

Ethanamide

Examples of Amines

Amines are found

• _{in the body and in drugs}

• _{in amino acids}

Examples of Amides

Amides are found

• _{in sweeteners}

• _{in peptide bonds between}

amino acids in proteins

34

Learning Check

Classify each of the following as alcohol, ether,

aldehyde, ketone, carboxylic acid, ester, amide, or amine:

1. CH₃─CH₂─CH₂─OH 2. CH₃─O─CH₂─CH₃ 3. CH₃─CH₂─NH₂

O O ║ ║

Functional Group Condensed Formula Suffix

Alkane -C-C- -ane

Alkene -C=C- -ene

Alkyne -C≡C- -yne

Alcohol R-OH -ol

Ether R-O-R -ether

Aldehyde R-CHO -al

Ketone R-CO-R -one

Carboxylic Acid R-CO₂H or R-COOH -ic acid

Ester R-COOR -oate

Nomenclature – alkanes

•

_{Find the longest chain of carbon atoms ---}

this is the base name of the alkane.

•

_{Alkyl groups branch off of the main chain}

43

Naming Alkanes with Substituents

In the IUPAC system,

• _{a carbon branch is named as an alkyl}

group

44

Learning Check

Give the IUPAC name of

Cl CH₃

 

45

Learning Check

Give the IUPAC name for the following:

Cl CH₃ | |

CH₃─CH₂─CH─CH₂─C─CH₂─CH₃

46

Learning Check

47

Unsaturated Compounds: Alkenes

and Alkynes

Unsaturated compounds

• _{have fewer hydrogen}

atoms attached to the

carbon chain than alkanes

• _{are alkenes with C=C}

double bonds

48

Naming Alkenes and Alkynes

The names of alkenes and alkynes

• use the corresponding alkane names

• change the end to ene for alkenes

49

Learning Check

Write the IUPAC name for the following: Br



50

Learning Check

Cycloalkanes

cyclopropane CH2 CH₂ H₂C

cyclobutane CH2_CH 2 CH₂ H₂C

cyclopentane

CH₂

CH₂ CH₂ CH₂

H₂C

or

or

52

Benzene

Benzene

• has six electrons shared equally among six carbon atoms in a ring

• is written as two possible ring structures

53

54

Naming Aromatic Compounds

Aromatic compounds are named

• with benzene as the parent chain

• with the name of a substituent in front of the

name benzene

• with common names for some substituted

55

Naming Aromatic Compounds

56

Example of Naming an Aromatic

Compound

57

Compounds with Oxygen

Atoms

Alcohols

• contain a hydroxyl group (-OH)

Phenols

58

Naming Alcohols

Alcohols are named

• _{with an IUPAC name that replaces the e in alkane}

name with ol

• _{as simple alcohols using the name of the alkyl}

group of the corresponding alkane followed by alcohol

CH₄ methane

CH₃─OH methanol (methyl alcohol) CH₃─CH₃ ethane

59

Phenols

Phenol

• _{is the IUPAC name for benzene}

with a carbon attached to an OH hydroxyl group

• _{is part of the structure of many}

60

Derivatives of Phenol

61

Ethers

An ether

• _{contains an ─O─ between two carbon atoms} • _{has a common name of the two alkyl names}

62

Carbonyl Group in Aldehydes and

Ketones

The carbonyl group

• _{in an aldehyde is}

attached to at least one H atom

• _{in a ketone is attached}

63

Carboxylic Acids

A carboxylic acid

• contains a carboxyl group, which is a carbonyl

group attached to a hydroxyl group

64

Naming Carboxylic Acids

Carboxylic acids are named

• _{in the IUPAC system by replacing the e in the alkane}

name of the longest carbon chain with oic acid

• _{with common names using prefixes: form, acet,}

propion, and butyr

H─COOH methanoic acid formic acid

CH₃─COOH ethanoic acid acetic acid

CH₃─CH₂─COOH propanoic acid propionic acid

65

Example of Naming a Carboxylic

Acid

Give the IUPAC name of the following: CH₃

|

CH₃—CH—CH₂—COOH

STEP 1 Identify the carbon chain containing the carboxyl group and replace the e in the alkane name with oic acid.

66

Example of Naming a Carboxylic

Acid

(continued)

STEP 2 Give the location and name of each

substituent on the main chain by counting the carboxyl group as carbon 1.

CH₃

|

CH₃—CH—CH₂—COOH

4 3 2 1

67

Learning Check

Give the IUPAC name for the following:

CH₃ CH₃

| |

68

Esters

In an ester, the H in the carboxyl group is replaced with an alkyl group.

O ║

CH₃—C—O—CH₃ ester group

The ester methyl ethanoate (methyl

69

Amines

Amines

• are derivatives of

ammonia, NH₃

• contain N attached to one

70

Aromatic Amines

71

Alkaloids

Alkaloids are

• _{physiologically active nitrogen-containing}

compounds obtained from plants

• _{used as anesthetics, antidepressants, and}

stimulants such as caffeine

• _{often addictive}

Caffeine is a stimulant found in coffee, tea, energy drinks, and

72

Morphine and Codeine

Morphine and codeine are

• _alkaloids

• _{found in the oriental}

poppy plant

Cocaine

Coc-H

Cl

+ NaHCO

3

→ Coc + H

O + CO

+ NaCl

Half life = 1 hour

74

Amides

Amides

• are derivatives of carboxylic

acids

• have an amino (-NH₂) group

that replaces the –OH group