Download 2202 Chapter 9 10 11 Partial

Unit 3 Organic
Chemistry
Chemistry 2202
CHAPTERS 9-11 (PARTIAL)
Introduction

Organic Chemistry is the study of the
molecular compounds of carbon.


eg. CH4
CH3OH
CH3NH2
Organic compounds exclude oxides of
carbon and ions containing carbon.

ie. CO, CO2, KCN, CaCO3
are NOT organic compounds!!
History of Organic Chemistry


Can be traced back to ancient times when
medicine men extracted chemicals from
plants and animals to treat members of their
tribes
First defined as a branch of modern science
in the early 1800's by Jon Jacob Berzelius



Berzelius believed in Vitalism - organic
compounds could only originate from living
organisms through the action of some vital
force
organic compounds originate in living or
once-living matter
inorganic compounds come from "mineral" or
non-living matter


In 1828, Friedrich Wöhler discovered that
urea - an organic compound - could be made
by heating ammonium cyanate (an inorganic
compound).
NH4OCN(aq)  (NH2)2CO(s)
inorganic
organic


organic chemistry branched into disciplines
such as polymer chemistry, pharmacology,
bioengineering and petro-chemistry
98% of all known compounds are organic

The huge number of organic compounds is
due mainly to the ability of carbon atoms to
form stable chains, branched chains, rings,
branched rings, multiple rings, and multiple
bonds (double and triple bonds) to itself and
to many other non-metal atoms.
Sources of Organic
Compounds
1.
Carbonized Organic Matter


2.
fossil fuels such as coal, oil, and natural gas
basis for the petrochemical industry
Living Organisms


penicillin from mold
ASA from the bark of a willow tree
Sources of Organic
Compounds
3.
Invention


antibiotics, aspirin, vanilla flavoring, and heart
drugs are manufactured from organic starting
materials
plastics
Structural Isomers


Structures that have the same molecular
formula but different structural formulas are
called structural isomers
eg. C4H10
Structural Isomers

Draw all structural isomers
of C5H12 and C6H14
Structural Isomers

Have the same chemical formula but have
different chemical and physical properties.

Handout Organic #1
Classifying Organic
Compounds
Organic
Compounds
Hydrocarbons
Hydrocarbon
Derivatives
Classifying Organic
Compounds

hydrocarbons consist of carbon and
hydrogen atoms only


Methane - CH4
hydrocarbon derivatives have one or more
hydrogen atoms replaced by another
nonmetallic atom


bromomethane - CH3Br
methanol - CH3OH
Hydrocarbons
Aliphatic
Hydrocarbons
Aromatic
Hydrocarbons
(benzene based)
AlkAnes
AlkEnes
AlkYnes
Hydrocarbons


aliphatic hydrocarbons have carbon atoms
bonded in chains or rings with only single,
double, or triple bonds
aromatic hydrocarbons contain at least one 6
carbon benzene ring
Aliphatic Hydrocarbons

1. Alkanes

hydrocarbons that have only single bonds
between carbon atoms
general formula CnH2n+2

eg. C3H8

C6H14
IUPAC
prefixes
Prefix
meth
eth
prop
but
pent
hex
hept
oct
non
dec
# of carbon
atoms
1
2
3
4
5
6
7
8
9
10
Complete this methane
ethane
table for the
first 10 alkanes propane
CH4


A series of compounds which differ by the
same structural unit is called a homologous
series
eg. each successive member of the
alkanes increases by CH2
Representing Alkanes (4 ways)
1.

Structural formulas
eg. propane
H
H
H
H–C–C–C–H
H
H
H
Representing Alkanes (4 ways)


Hydrogen atoms may be omitted from
structural formulas
eg. propane
–C–C–C–
Representing Alkanes (4 ways)
2.
Condensed Structural Formula

eg. Propane
CH3-CH2-CH3
Representing Alkanes (4 ways)

3. Line Structural Diagrams

eg: propane

(the endpoint of each segment is a carbon atom)
Representing Alkanes (4 ways)

4. Expanded Molecular Formulas

eg. Propane
CH3CH2CH3
Alkyl Groups




An alkyl group has one less hydrogen than
an alkane.
General Formula: CnH2n + 1
To name an alkyl group, use the prefix to
indicate the # of carbon atoms followed by
the suffix –yl
eg. -C7H15
heptyl
Alkyl Groups
methyl -CH3
ethyl -C2H5 or -CH2CH3
propyl -C3H7 or -CH2CH2CH3
Alkyl Groups

Branched alkanes are alkanes that contain
one or more alkyl groups

eg.
Naming Branched Alkanes
1.
Find the longest continuous chain of
carbons and name it using the alkane name.
This is the parent chain.
1.
Number the carbons in the parent chain
starting from the end closest to branching.
These numbers will indicate the location of
alkyl groups.
Naming Branched Alkanes
3.
List the alkyl groups in alphabetical order.
Use Latin prefixes if an alkyl group occurs
more than once.
(di = 2, tri = 3, tetra = 4, etc.)
4.
Use a number to show the location of each
alkyl group on the parent.
Naming Branched Alkanes
5.
Use commas to separate numbers, and
hyphens to separate numbers and letters.
Naming Branched Alkanes
eg.
ethyl
7
6
5
4
3
2
1
methyl
4-ethyl-3-methylheptane
Naming Branched Alkanes


Pages 336 - 339 #’s 5 – 11
Handout Organic #2
Alkenes and Alkynes

saturated compounds contain only single
bonds between carbon atoms


eg. alkanes
saturated compounds have the maximum
number of hydrogen atoms bonded to carbon
atoms
Alkenes and Alkynes



unsaturated compounds contain double or
triple bonds between carbon atoms
eg. alkenes and alkynes
General Formulas:


Alkenes
Alkynes
CnH2n
CnH2n - 2
Naming Alkenes and Alkynes
1.
Name the longest continuous chain that
contains the double/triple bond. Use the
smallest possible number to indicate the
position of the double or triple bond.
Naming Alkenes and Alkynes
2.
Branches are named using the same rules
for alkanes. Number the branches starting
at the same end used to number the multiple
bond.
Naming Alkenes and Alkynes



Page 347 #’s 17 - 19
Page 354 #’s 28 & 29
Handout Organic #3
Cyclic hydro carbons


Carbon chain is joined together to form a
circle
Lose two Hs
Naming cyclic hydrocarbons
1.
2.
3.
4.
Use the general formula (prefix + root +
suffix)
All carbons are equal start at 1 anywhere
Two or more branches, CW or CCW
Double bonds must be 1 and 2
3-ethyl-1-methylcyclopentane
cyclopentane
2
1
ethyl
3
methyl
1-ethyl-3-methylcyclopentane
methyl
1,2,3,4-tetramethylcyclohexane
Cyclic Hydrocarbons

Pages 356 – 358


questions 30 & 31
Handout Organic #4
Aromatic Compounds



Aromatic hydrocarbons contain at least one
benzene ring.
The chemical formula for benzene, C6H6 ,
was determined by Michael Faraday in 1825.
Structural formula was determined by August
Kekulé in 1865.
Aromatic Compounds

benzene ring consists of six carbon atoms,
each of which is bonded to a hydrogen atom


(Try to draw this!!)
C6H6 can be drawn with alternating single
and double bonds.
Aromatic Compounds


While C=C double bonds are shorter than CC single carbon bonds, x-ray crystallography
shows that all six C-C bonds in benzene are
the same length.
Benzene molecules behave like alkanes in
chemical reactions, not like the alkenes
Aromatic Compounds


Kekulé thought benzene could exist in two
forms and used the idea of resonance to
explain its structure.
The resonance structure is an average of
the electron distributions.
Aromatic Compounds
or
Aromatic Compounds


bonding electrons that were thought to be in
the double bonds are delocalized and
shared equally over the 6 carbon atoms
the bonds in benzene are like “1 ½” bonds –
somewhere between single and double.
Naming Aromatic Compounds


an alkyl benzene has one or more H atoms
replaced by an alkyl group.
name the alkyl groups, using numbers where
necessary, followed by the word benzene.
Aromatic Compounds
methylbenzene
ethylbenzene
propylbenzene
Aromatic Compounds
1,3-dimethylbenzene
1,4-dimethylbenzene
1,2-dimethylbenzene
Aromatic Compounds
ortho- means positions 1 and 2 and is
represented by an italicized "o"
 meta- means positions 1 and 3 and is
represented by an italicized "m"
 para- means positions 1 and 4 and is
represented by an italicized "p"

Aromatic Compounds
m-dimethylbenzene
p-dimethylbenzene
o-dimethylbenzene
Aromatic Compounds


Benzene is treated as a branch if it is not
attached to the terminal carbon of an alkyl
group
Benzene as a branch is called phenyl
Aromatic Compounds
CH3
CH2
CH2
propylbenzene
2-phenylpropane
CH3 CH CH3
Aromatic Compounds
CH3 CH2 CH2 CH CH CH3
CH2
CH3
Aromatic Compounds
CH3
CH2
CH2 CH3
CH3 CH2 CH2 CH CH2 CH CH CH3
Aromatic Compounds
Page 361 #’s 32 – 35
 Pages 363, 364 #’s 4 – 9
 Handout organic #5

Hydrocarbon Derivatives


Hydrocarbon Derivatives have one or more H
atoms replaced by another nonmetallic atom
Types of derivatives:







alcohols
ethers
aldehydes
Ketones
carboxylic acids
organic halides
esters
Hydrocarbon Derivatives




A functional group is the reactive group of
atoms that gives a family of derivatives its
distinct properties.
The general formula for a derivative is
R - functional group
where R stands for any alkyl group.
Bonded to
Hydrocarbon Derivatives
eg. ALCOHOLS
ethanol
propanol
hydroxyl
group
R-OH
C2H5OH
carboxyl
C3H7OH group
CARBOXYLIC ACIDS R-COOH
ethanoic acid
CH3COOH
propanoic acid
C2H5COOH
Hydrocarbon Derivatives

Types of derivatives (See p. 378)






Alcohols – pp. 386 - 388
Ethers – pp. 394 – 396
Aldehydes & Ketones – pp. 402,403
Carboxylic Acids – pp.405, 406
Alkyl Halides – pp. 390, 391
Esters – pp. 410, 411
Structure and naming

Handout organic #6


Handout organic #7


Aldehydes and ketones
Handout organic #8


Alcohols and esthers
Caboxylic acids and alkyl halides
Handout organic #9

Esters
Reactions in hydrocarbons
1.

Combustion
Uses O2 to produce CO2 and H2O
Reactions in hydrocarbons
2.

Cracking and reforming
Cracking:



Large hydrocarbon is broken in smaller pieces
Requires H2
Reforming:


Small hydrocarbons combine
Releases H2
Reactions in hydrocarbons
3.



Substitution
In alkanes and aromatics
In the presence of light
H is replaced by and halogen
Reactions in hydrocarbons
4.


Addition
In alkene and alkynes
Molecules added across a double/triple
bond
Reactions in hydrocarbons
5.


Esterification
Between an alcohol and a carboxylic acid
Acid catalyst (H2SO4 or H+) and heat (Δ) is
necessary
Reactions in hydrocarbons
6.
Elimination
a)


In alcohol
Water is removed
Acid catalyst (H2SO4 or H+) and heat (Δ) is
necessary
Reactions in hydrocarbons
6.
Elimination
b)


In alkyl halide
Halogen atom is removed
Metal hydroxyde (eg. NaOH) is required

Handout organic #10