Organic Chemistry Chem 2014. Organic Chemistry Organic Chemistry: - the chemistry of carbon and carbon-based compounds - (C – C or C – H or C – R) - (can

Organic Chemistry

Chem 2014

Organic ChemistryOrganic Chemistry: - the chemistry of carbon

and carbon-based compounds- (C – C or C – H or C – R)- (can be a few to hundreds of carbons covalently

bonded to one another)

Characteristics of Organic Compounds: *Usually have strong odors and low boiling points * Most do not conduct electricity

* Most will ignite and burn * Slower rates of reactions

Smells & tastes: fruits, chocolate, fish, mint

Medications: Aspirin, Tylenol, Decongestants, Sedatives

Addictive substances: Caffeine, Nicotine, Alcohol, Narcotics

Hormones/Neurotransmitters: Adrenaline, Epinephrine

Food/Nutrients: Carbohydrates, Protein, Fat, Vitamins

Genetics: DNA, RNA

Consumer products: Plastics, Nylon, Rayon, Polyester

Organic Chemistry in everyday life:

• Animals, plants, and other forms of life consist of organic compounds.– Nucleic acids, proteins, fats, carbohydrates,

enzymes, vitamins, and hormones are all organic compounds

• Besides carbon, the most common elements in organic compounds are hydrogen, oxygen, nitrogen, sulfur, and the halogens.– All of the preceding elements are non-metals, therefore

organic compounds have covalent bonding.

Copyright © Houghton Mifflin Company. All rights reserved. 14 | 5

Numbers and Types of Bonds for Common Elements in Organic CompoundsApplication of the octet rule indicates that these elements should

bond as shown below:

Section 14.1

Review: Octet Rule

• Rule of Eight – elements want either 8 or 0 electrons in its outermost level (except for H and He which want 2 or 0)

Each energy level can only hold a certain number of electrons.

1st level 2 electrons2nd level 8 electrons3rd level 8 electrons4th level 18 electrons

*Helium only has 2 valence electrons

Group Number Number of Valence Electrons

1 1

2 2

13 3

14 4

15 5

16 6

17 7

18 8

Periodic Table and Valence electrons

• http://phet.colorado.edu/sims/html/build-an-atom/latest/build-an-atom_en.html

Let’s Practice Bohr DiagramsEnergy Levels Diagram HW wkst

http://phet.colorado.edu/sims/html/build-an-atom/latest/build-an-atom_en.html

Lewis Structure

Placing valence electrons around element symbol to decipher bonding patterns

Lets practice Lewis dot structures

Practice Lewis Dot Structures1. Oxygen (e = _________) 2. Potassium (e = _______) 3. Bromine (e = ________)

4. Germanium (e= ______) 5. Aluminum (e = ______) 6. Phosphorus (e = ______)

Big Idea in Organic Chemistry

Structure controls Function

Each functional group has predictable reactivity

= atom or group of atoms that gives characteristic chemical properties to a class of organic compounds

Drawing Organic Structures

Butane: C4H10

C C C C

H

H

H

H

H

H

H

H

H

H

CH3 CH2 CH2 CH3

CH3CH2CH2CH3

CH3(CH2)2CH3

Shortcuts make structures easier & faster to draw

Line Structure Carbon Skeleton

• Only shows bonds• C atoms assumed at each end and

intersection of bonds• H atoms not shown• Assume 4 bonds to each C• Fulfill C’s 4 bonds by adding H’s

Lewis Structure Structural formula

Condensed Structuresmolecular formula

Carbon Atoms

Types of Organic CompoundsClassified according to functional group

Alkane

Alkene

Alkyne

Halocarbon

Alcohol

Ether

Ketone

Aldehyde

Carboxylic acid

Amine

Amino acid

AmideO

H

O

NH2

O

OH

O

H2NOH

O

OH

Cl

Br

NH2

C C

O

Hyd

roca

rbon

s (H

& C

onl

y)

Ester

Characteristics and ExamplesHydrocarbons

Alkane Alkene Alkyne

Contain C – C single bond

C = Cdouble bond

C ≡ C triple bond

Formulan is # of carbons

CnH2n+2 CnH2n CnH2n-2

Naming Prefix (# of C’s)-ane # (count from smallest direction of =) – Prefix (# C’s) - ene

# (count from smallest

direction of ≡) – Prefix (# C’s) - yne

Examples See following Slides for examples

Linear/skeletal

structure

\/ \

Organic Prefixes

• Meth- 1 carbon• Eth- 2 carbon• Prop- 3 carbon• But- 4 carbon• Pent- 5 carbon• Hex- 6 carbon

• Hept- 7 carbon• Oct- 8 carbon• Non- 9 carbon• Dec- 10 carbon

Examples

NameMolecular Formula

Lewis/ Structural Formula

Condensed Structural Formula

Linear

propane C3H8 CH3CH2CH3 \/

ethane C2H6 CH3CH3 \

2-pentene C5H10 CH3CHCHCH2CH3

2-butene C4H8 CH3CHCHCH3

NameMolecular Formula

Structural Formula Condensed Structural Formula

3-heptyne C7H12 CH3CH2CCCH2CH2CH3

1-propyne

C3H5 CHCCH3


Alkanes – Energy Related Products

• Methane = primary component of natural gas• Propane & Butane = primary component of

bottled gas• Gasoline = pentane to decane• Kerosene = alkanes with n = 10 to 16• Alkanes with n > 16 diesel fuel, fuel oil,

petroleum jelly, paraffin wax, lubricating oil, and asphalt

Section 14.3


Organic Compound Nomenclature

• Due to the large number, variety, and complexity of organic compounds, a consistent method of nomenclature has been developed.

Section 14.3


IUPAC System of NomenclatureFor Alkanes

• Compound is named as a derivative of the longest continuous chain of C atoms.

• Positions & names of the substituents added– If necessary, substituents named alphabetically– More than one of same type substituent – di, tri, tetra

• The C atoms on the main chain are numbered by counting from the end of the chain nearest the substituents.– Each substituent must have a number.

Section 14.3

Hydrocarbons wkst

Names of Linear Alkanes and Alkyl Substituents

Alkane Alkyl substituents# of

C atoms

CH4

CH3CH3

CH3CH2CH3

CH3CH2CH2CH3

-CH3

-CH2CH3

-CH2CH2CH3

Methyl

Ethyl

Propyl

etc.

Methane

Ethane

Propane

Butane

Pentane

Hexane

Heptane

Octane

Nonane

Decane

Root: number of C atomsSuffix: functional group (-ane for alkanes) (-yl for alkyl groups)

1

2

3

4

5

6

7

8

9

10


An Example to Consider• The longest continuous chain of C atoms is five• Therefore this compound is a pentane derivative

with an attached methyl group– Start numbering from end nearest the substituent– The methyl group is in the #2 position

• The compound’s name is 2-methylpentane.

Section 14.3


Drawing a Structure from a NameAn Example

• Draw the structural formula for 2,3-dimethylhexane.

• Note that the end name is hexane .• Draw a continuous chain of six carbon (C)

atoms, with four bonds around each.

Section 14.3


Drawing a Structure from a NameAn Example (cont.)

• Number the C atoms from right to left.• Attach a methyl group (CH3--) to carbon

number 2 and number 3.– Add necessary H atoms.

• 2,3-dimethylhexane

Section 14.3


Drawing a Structure from a NameConfidence Exercise

• Draw the structural formula for 2,2,4-trimethylpentane.

• Note that the end name is pentane .• Draw a continuous chain of five carbon (C)

atoms, with four bonds around each.

Section 14.3


Drawing a Structure from a NameConfidence Exercise (cont.)

• Number the C atoms from right to left.• Attach two methyl groups (CH3--) to carbon

number 2 and one to number 4.

Section 14.3


Drawing a Structure from a NameConfidence Exercise (cont.)

• Add necessary H atoms.• 2,2,4-trimethylpentane

Section 14.3

C H

H

H

H

Methane CH4

H

CC C C

H H H

H

HHHH

H

Butane C4H10

Butyl -C4H9

Methyl-CH3

C H

H

H

?R

H

CC C C

H H H

H

HHHH

?

Where R = any other C atom or arrangement of C atoms

R

H

C H

H

H CC C

H H

HHH

C

H

HH

2 - methylbutane

Example of R groupExpanded Structure

Line Structure

First Ten Hydrocarbons: PropertiesName

Methane

Ethane

Propane

Butane

Pentane

Hexane

Heptane

Octane

Nonane

Decane

1

2

3

4

5

6

7

8

9

10

CH4

C2H6

C3H8

C4H10

C5H12

C6H14

C7H16

C8H18

C9H20

C10H22

Number ofCarbon Atoms

Molecular Formula

Melting Point, oC

# of Isomers

Boiling Point, oC

-182.5

-183.2

-187.7

-138.3

-129.7

- 95.3

- 90.6

- 56.8

- 53.6

- 29.7

-161.5

-88.6

-42.1

-0.5

36.1

68.7

98.4

125.7

150.8

174.0

1

1

1

2

3

5

9

18

35

75

Properties of Alkanes

CompoundMethaneEthanePropaneButanePentane

MW1630445872

Boiling point (°C)-164-88.6-42.1-0.5

+36.0

Linear Alkanes:1 - 4 C atoms: gas at room temp

5 - 15 C atoms: liquid at room temp>15 C atoms: solid at room temp

Larger molecular weight → Stronger London dispersion forcesNonpolar → only London Dispersion Forces IMF

Formula

CH4

C2H6

C3H8

C4H10

C5H12

Naming Branched Alkanes (IUPAC)

1. Root name: name of longest continuous C chain (parent chain)• 2 equally long? Choose the one with more branches

2. Number C atoms in chain, starting at end with first branch3. Identify substituents, give each a number (C it is connected to)

• Two or more identical substituents: use prefixes (di-, tri-, tetra-, etc.)

4. List substituents alphabetically before root name• Do not alphabetize prefixes

5. Punctuation: commas separate numbers from each otherhyphens separate numbers from namesno space between last substituent & root name

4-ethyl-3,5-dimethyloctane1

2

3

658

74

4-ethyl

3-methyl and 5-methyl = 3,5-dimethyl

Octane


Alkenes are very Reactive and are termed “unsaturated hydrocarbons”

• Alkenes will characteristically react with hydrogen to form the corresponding alkane.

Section 14.3


Alkynes are Unsaturated Hydrocarbons

• Due to the triple carbon bond, each alkyne molecule can react with two molecules of hydrogen.

Section 14.3

Chapter 26

Hydrocarbon Derivatives

Hydrocarbon Derivatives

Derivatives = molecules that contain C and H, as as hydrocarbons, but also contain other elements

• derivatives depend on their functional groups which are atoms or group of atoms that give the derivative its characteristic chemical behavior

Derivatives

Alkane

Alkene

Alkyne

Halocarbon

Alcohol

Ether

Ketone

Aldehyde

Carboxylic acid

Amine

Amino acid

AmideO

H

O

NH2

O

OH

O

H2NOH

O

OH

Cl

Br

NH2

C C

O

Esters

Halocarbon Definition One or more of hydrogen atoms replaced with a member of

halogen family

General Formula R – XR symbolizes the hydrocarbon portionX symbolizes the halogen atomX can be F, Cl, Br, or I

Naming (IUPAC)

1. Name hydrocarbon portion2. Add prefix to indicate halogen, add -o3. # of halogen placement

Properties Primarily non polarLow boiling pointsInsoluble in waterSoluble in hydrocarbon solvent

Structure

Examples CFC’s –chlorofluorocarbons Methanol (aerosol cans, refrigerate gases) PesticidesDry cleaning chemicals

AlcoholsDefinition One or more of hydrogen atoms replaced with a member of

hydroxyl group (-OH)

General Formula R – OHR symbolizes the hydrocarbon portionOH – hydroxyl group

Naming (IUPAC)

Suffix –ol added to hydrocarbon root

Properties *Similar to water (OH)*Up to 4 C are soluble in water*Higher boiling points *Can be –diol (2 –OH) or –triol (3 -OH)

Structure

Examples

Methanol Ethanol – grain alcohol

Butanol

Definition Oxygen atom that is bonded to two carbon atoms

General Formula R – O – R’R and R’ → hydrocarbon chains-O- → functional group

Naming (IUPAC)

1. Suffix –oxy added to smaller chain bonded to central oxygen atom, remainder is named as before2. Or use similar name: add suffix –yl to each hydrocarbon and add ether

Properties Oxygen creates slightly polar regionSome smaller molecules are soluble in waterNo H bonds so lower boiling points than alcohol but higher than hydrocarbons

Structure

Examples

Ethe

rs

Worksheet Review

Definition -oxygen atom bonded to single carbon atom by a double bond -called a carbonyl group (C=O) Aldeyde has carbonyl group attached to end of hydrocarbon chain

General Formula R – CHO

Naming (IUPAC)

Add suffix –al to the root name

Properties More polar than hydrocarbonsHigher melting and boiling points than hydrocarbonsLower melting and boiling points than alcohol

Structure

Examples -Methanol (HCOH) = formaldehyde – used to make polymers and used to be used for biological preservation – found to be carcinogenic-Used as flavorings in food and candy and as fragrances in inhalants and perfumes-Vanilla flavor in ice cream and cinnamon in hot chocolate

Alde

hyde

s

Keto

nes

Definition Ketone has a carbonyl group on the interior of a hydrocarbon

General Formula R-COR’

Naming (IUPAC)

Add suffix –one to the root nameName must include which C it is attached to b/c always on interior C when a Ketone

Properties More polar than hydrocarbonsHigher melting and boiling points than hydrocarbonsLower melting and boiling points than alcohol

Structure

Examples -Propanone (CH3COCH3) = acetone - volatile liquid and vapor is flammable-Cortisone= hormonal response to fight or flight, treatment of severe allergic reactions; too much bad b/c breaks down connective tissue, increases production of stomach acid and decreasing protective mucus membranes resulting in gastric ulcer

Worksheet Review

Definition Characterized by presence of a carboxyl group

General Formula R – COOH

Naming (IUPAC)

Prefix + -anoic acid

Properties -carboxyl end is very polar making it soluble in water-higher boiling points than hydrocarbons

Structure

Examples

(see also book pg 852)

-Fatty acids -Formic acids (simplest form HCOOH) – from ants-Acetic acid – (CH3COOH) – responsible for sour taste of vinegar-lactic acid – responsible for sour cow’s milkCa

rbox

ylic

Aci

ds

Definition Similar to carboxylic acid, but has hydrocarbon group in place of H atom of carboxy group

General Formula

R-COOR’

Naming (IUPAC)

-named for the alcohol and acid from which they are produced-alcohol name (suffix changed to –yl) + acid name (suffix changed to –oate)

Example : ethanol + propanoic acid = ethyl propanoate

OR-alcohol name (-yl) + acid (-ate) = propyl alcohol + formic acid = propyl formate

Properties -polar but do not form H bonds with each other-boiling points are lower than BP of similar alcohols or acids -distinctive odors based on alcohol and acid reaction (typically fruity odors)

Structure

Examples

(see also book pg 856)

Este

r

Worksheet Review

Definition Contains an amino group (-NH2) attached to hydrocarbon chain

General Formula R-NH2 2◦ = R-NHR’ 3◦ = R-NR’R”

Naming (IUPAC)

-add suffix –amine to root name of hydrocarbon

Properties -amino group is polar -higher boiling points than HC but lower than alcohols-weak bases

Structure

Examples -amino groups found in DNA, vitamins, anesthetic drug-basis of nicotine, cocaine, amphetamines-unpleasant odors = cadaverine produced by bacteria on decaying organisms – can cause food poisoning-found in suntan lotion

Amin

es

Definition Amino group attached to carbon of carboxyl group

General Formula R-CONH2

Naming (IUPAC)

-add suffix –amide to root of hydrocarbon

Properties

Structure

Examples

Amid

es

nylon and urea, which exist in chains, and caffeine, which exists in a ring

Worksheet Review

Documents

Organic Chemistry Chem 2014. Organic Chemistry Organic Chemistry: - the chemistry of carbon and carbon-based compounds - (C – C or C – H or C – R) - (can