organic chemistry
Organic chemistry is the study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds, which include not only hydrocarbons but also compounds with any number of other elements, including hydrogen
4. What is Chemistry ?
Composition
Chemistry
StructureProperties
What in the world isn’t Chemistry??
5. Branches of
chemistry
I. Physical chemistry
II. Organic chemistry
III. Inorganic chemistry
IV. Analytical chemistry
V. Industrial chemistry
VI. Bio chemistry
VII. Nuclear chemistry
VIII. Agricultural chemistry
IX. Geo chemistry
8. What is pencil lead made of if it isn't lead?
Pencil lead is a mixture of
graphite and clay.
Graphite is one form of the
element carbon.
Other forms of carbon are
diamond - the hardest naturally
occurring substance on the
earth, soot, charcoal and coke.
10. “I used to experiment with
Chloroform as I wanted to get
into the subconscious mind. It
is a highly powerful state of
mind where you can memorise
quickly.”
11.
12. “My mother made me a scientist without ever intending to. Every other Jewish mother in
Brooklyn would ask her child after school: So? Did you learn anything today? But not my
mother. “Izzy,” she would say, “did you ask a good question today?” That difference — asking
good questions — made me become a scientist.”
The Nobel Prize in Physics 1944 was awarded to Isidor Isaac
Rabi "for his resonance method for recording the magnetic
properties of atomic nuclei".
13.
14. What is Organic chemistry?
The study of carbon and its compounds.
First we will concentrate on compounds just containing carbon
and hydrogen, these compounds are called hydrocarbons.
Hydrocarbon Classification
Hydrocarbons
Alkanes AlkenesCycloalkanes AlkynesCycloalkenes
16. Sometimes the hydrocarbon chains are
not straight and sometimes they have
other elements attached to them. Here is
how they are named:
CH3 - CH2 - CH2 – CH – CH – CH - CH3
CH2 CH3
CH3
CH3
17. CH3 - CH2 - CH2 – CH – CH – CH - CH3
CH2 CH3
CH3
CH3
Step 1: Find the longest continuous chain of
carbons.
1234567
There are 7 continuous carbons, so the parent chai
is heptane.
All bonds in the chain of carbons
are single bonds so ending is… ane.
18. • Step 2: Number the carbons in the main
sequence starting with the end that will give the
attached groups the smallest #.
This chain is numbered from right to left because
there is a substituent closest to the right.
CH3 - CH2 - CH2 – CH – CH – CH - CH3
CH2 CH3
CH3
CH3
1234567
1 2 3
4 5 6 7
19. • Step 3 : Add numbers to the names of the groups to
identify their positions on the chain.
- these numbers become prefixes to the parent chain.
In this ex. the positions are:
- methyl, - methyl, - ethyl
CH3 - CH2 - CH2 – CH – CH – CH - CH3
CH2 CH3
CH3
CH3
1234567
2 3 4
ethane
yl
C2H6
5
20. • Step 4: Use prefixes to indicate the appearance of a
group more than once in the structure.
CH3 - CH2 - CH2 – CH – CH – CH - CH3
CH2 CH3
CH3
CH3
1234567
Di =
Tri =
= four times
= five times
twice
three times
Tetra
Penta
21. • This chain has 2 methyl groups so
is used.
CH3 - CH2 - CH2 – CH – CH – CH - CH3
CH2 CH3
CH3
CH3
1234567
dimethyl
Step 5: List the alkyl groups in alphabetical order.
In this ex. dimethyl is listed before the ethyl.
22. CH3 - CH2 - CH2 – CH – CH – CH - CH3
CH2 CH3
CH3
CH3
1234567
Step 6: Use punctuation
- use commas to separate numbers
-hyphens to separate numbers with
words.
23. • The name of this compound is:
CH3 - CH2 - CH2 – CH – CH – CH - CH3
CH2 CH3
CH3
CH3
1234567
2,3-dimethyl – 4-ethyl heptane
24. Organic Chemistry- The study of
carbon & carbon compounds
• Organic compounds are the primary
constituents of all living organisms.
25. What makes carbon so special?
• It has a “central” role in all living organisms.
• It has 4 valence electrons.
• It makes 4 covalent bonds.
• It can bond with any
element,
but really loves to bond with other carbon atoms and
make long chains
26. CONTENTS
SPECIAL NATURE OF CARBON - CATENATION
CATENATION is the ability to form bonds between atoms of the same element.
Carbon forms chains and rings, with single, double and triple covalent bonds, because it is able to FORM
STRONG COVALENT BONDS WITH OTHER CARBON ATOMS
Carbon forms a vast number of carbon compounds because of the strength of the C-C covalent bond.
Other Group IV elements can do it but their chemistry is limited due to the weaker bond strength.
BOND ATOMIC RADIUS BOND ENTHALPY
C-C 0.077 nm +348 kJmol-1
Si-Si 0.117 nm +176 kJmol-1
The larger the atoms, the weaker the bond. Shielding due to filled inner orbitals and greater distance from the
nucleus means that the shared electron pair is held less strongly.
29. Silicon is similar to carbon. Why are there no
life forms based on silicon?
Silicon is unsuitable because, although it is a valence
IV element like carbon (4 electrons to share),
BUT the silicon-silicon covalent bond is not strong
enough for it to form long stable chains.
So, it can not form molecules of the complexity
needed to make up cells like carbon can!
30. Characteristics of Organic Compounds
• They are nonpolar compounds – they do not
dissolve in polar solvents like Water.
*remember the rule –
“likes dissolve likes”
O -
H + +H
31.
32. • These plants and their flowers are
made up of a mixture of carbohydrates
that were manufactured from carbon
dioxide and water, with the energy of
sunlight. The simplest of the
carbohydrates are the
monosaccharides, simple sugars (fruit
sugar) that the plant synthesizes. Food
is stored as starches, which are
polysaccharides made from the simpler
monosaccharides. The plant structure
is held upright by fibers of cellulose,
another form of a polysaccharide.
33. • Ethylene is the gas that ripens fruit, and a ripe fruit emits the gas, which
will act on unripe fruit. Thus, a ripe tomato placed in a sealed bag with
green tomatoes will help ripen them.
34. • Crude oil from the ground is separated into usable groups of
hydrocarbons at this Louisiana refinery. Each petroleum
product has a boiling point range, or "cut," of distilled vapors that
collect in condensing towers.
35. • Refinery and tank storage facilities, like this one in Texas, are needed
to change the hydrocarbons of crude oil to many different petroleum
products. The classes and properties of hydrocarbons form one topic of
study in organic chemistry.
36. • Gasoline is a mixture of hydrocarbons (C8H18 for example) that contain
no atoms of oxygen. Gasohol contains ethyl alcohol, C2H5OH, which
does contain oxygen. The addition of alcohol to gasoline, therefore,
adds oxygen to the fuel. Since carbon monoxide forms when there is an
insufficient supply of oxygen, the addition of alcohol to gasoline helps
cut down on carbon monoxide emissions. An atmospheric inversion,
with increased air pollution, is likely during the dates shown on the
pump, so that is when the ethanol is added.
37. • These red ants, like other ants, make the simplest of the organic acids,
formic acid. The sting of bees, ants, and some plants contains formic
acid, along with some other irritating materials. Formic acid is
HCOOH.
38. I’m made of what???
• Guess how many elements your body is
made up of?
• 25 elements make up all living things
• About 97% of your body’s mass is made
of just 4 elements: oxygen, carbon,
hydrogen, & nitrogen.
• Two other major elements are
phosphorous & sulfur.
39. The most important element is…
• The word “organic” has lots of
meanings. Eventually, scientists
realized that the reactions occurring
inside the body could occur outside
it as well.
• They also learned how important
carbon is in all living things,
because of its ability to bond with
other atoms.
44. So, what do u think about table salt,
chlorophyll & hemoglobin ??
45. Polymers
.Teflon is polymer with a strong bond between carbon
and fluorine atoms. It is used as a no-stick surface in
cookware.
46. Cellulose in wood is extracted and converted to paper at
this plant in Maine. Microorganisms in the stomachs of
cows help them digest cellulose in plants.
Polysaccharides
49. Organic and
Biological
Chemistry
Chirality
• Carbons with four different groups attached to them are
handed, or chiral.
• Optical isomers or stereoisomers
• If one stereoisomer is “right-handed,” its enantiomer is “left-
handed.”
52. Organic and
Biological
Chemistry
Amino Acids and Proteins
• Proteins are polymers of -
amino acids.
• A condensation reaction
between the amine end of
one amino acid and the acid
end of another produces a
peptide bond.
53. Organic and
Biological
Chemistry
Amino Acids and Proteins
• Hydrogen bonding in
peptide chains causes coils
and helices in the chain.
• Kinking and folding of the
coiled chain gives proteins
a characteristic shape.
62. Alkanes = CnH2n+2
• A saturated hydrocarbon contains 20 carbons.
What is the formula?
C20H2(20)+2 = C20H42
• A saturated hydrocarbon contains 5 carbons.
What is the formula?
=C5H2(5)+2
Saturated = Single
C5H12
66. Naming Organic Compounds
• Organic compounds are named according to the
IUPAC (international union of pure & applied
chemistry) system of nomenclature.
Alkanes – end in
Alkenes – end in
Alkynes – end in
ane
ene
yne
67. Alkenes – CnH2n
series of unsaturated hydrocarbons having
one double bond (C=C)
• Also called ethylene series
(IUPAC name is ethene)
• General formula CnH2n
68. Alkenes
• C2H4 = Ethene
• C3H6 = Propene
• C4H8 = Butene
• C5H10 = Pentene
• To find the number of
hydrogens, double the
number of carbons.
69. 1-Butene
This is 1-butene, because the double bond is
between the 1st and 2nd carbon from the end.
ISOMERS: Molecules have the same
molecular formula, but have different
structural formulas.
70. This is 1-pentene. The double bond is on the
first carbon from the end.
This is not another isomer of pentene. This is
also 2-pentene, just that the double bond is
closer to the right end.
Pentene
71. Alkynes –
a series of unsaturated hydrocarbons that
contain 1 triple bond.
• Also called the acetylene series
General formula CnH2n-2
C C
76. Carbon forms Rings
• Carbon-based molecules also can be shaped like rings. Most carbon
rings contain 5 or 6 carbon atoms.
• One of the most important carbon rings is benzene.
• It has 6 carbons & 6 hydrogens , with alternating double bonds.
77. Carbon forms Rings
• Many compounds are based on Benzene.
• They often have very strong smells or aromas, so they are
called aromatic compounds.
• An example of one aromatic compound is a molecule called
vanillin.
• Guess what that smells like!
78. Benzene – a series of cyclic unsaturated
hydrocarbons.
General formula CnH2n-6
Benzene – C6H6 the simplest in the family
C
C
C
C
C
C H
H
H
H
H
H
80. Step 1: 6 carbons =
CH3 - CH2 – CH – CH2 – CH - CH3
123456
CH3 CH3
hex
All single bonds = ends in ane
hexane
Step 2: start numbering from right to left
Step 3: -methyl and -methyl2 4
So parent chain is
82. C CC C C
CH3 CH3
1 2 3 4 5
3,4 dimethyl, 2-pentene
When naming with a double/triple bond-start #
carbons closest to the bond.
83. Now start with name and draw the structure.
• 3-ethylhexane
CC CC C C
CH2
CH3
You can place H’s all around or just leave as is.
ethane
yl
C2H6
5
C
C
HH
H H
H
85. Other Organic Compounds
Functional Groups – specific groupings of atoms that give
characteristic properties to organic compounds.
halides F (fluoro-)
Cl (chloro-)
Br (bromo-)
I (iodo-)
What group do these belong to?
Halogens
97. IUPAC naming of Aldehydes-
• Replace the final “e” the the ending “al”
First member of the aldehyde family is methanal
-its common name is formaldehyde
C
H
O
H
1
2
3
4
Used to preserve
biological
samples
98. • Alcohols can be oxidized to aldehydes
C
H
R
H
OH + Oxidizing
agent
C
H
O
R + H20
methanol methanal water
100. Ketones – contain the functional group R-
CO-R
• The simplest member of the
ketone family is propanone.
Replace the final “e” with “-one”.
101. • IUPAC name is propanone but its common
name is acetone, it is an important industrial
solvent.
C
H
H
C
H
H
H C
O
H
RR
102. Ethers -
• when two primary alcohols are treated with a
dehydrating agent, water is removed and the 2
alcohols are joined together by an oxygen
“bridge”.
R-OH + R-OH R-O-R + H20
Primary
alcohol
Primary
alcohol
ether
H2O
103. Diethyl ether- used as a general
anesthetic
C
H
H
C
H
H
H O H
ethylethyl
C
H
H
C
H
HOxygen bridge
-O-
Condensed formula
CH2CH3 CH2 CH3
106. Esters – are organic cmpds with the
general formula R-CO-O-R
OC
O
They are formed in a rxn
between an organic acid and
an alcohol.
Esters have strong fragrant aromas and are what
make pineapples, bananas, wintergreen & oranges
so YummY!
Draw this:
107. IUPAC naming of Esters:
1. Look at chain after the –C-O- write its prefix
Ex.(meth,eth, etc.) and add –yl to the end of prefix
OC
O
C
H
H
H
C
H
H
C
H
H
C
H
H
H
O
In this ex. : eth + yl = ethyl
108. 2. Give the name of the carbon chain that includes the
C=O, leave off the last letter and add –oate.
OC
O
C
H
H
H
C
H
H
C
H
H
C
H
H
H
Propane - 3 C’s and single bonds
Ethyl propanoate
propane + oate = propanoate
Condensed formula
CH3 CH2 COO CH2CH3
109. Ex.) Draw ethyl pentanoate
OC
O
C
H
H
H
C
H
H
C
H
H
C
H
H
HC
H
H
C
H
H
Now you’ve got it!
110. Amines – contain the functional group -N-
• It is a derivative of ammonia – NH3
• IUPAC naming of amines –
- replace the final –e with “-amine”
C
H
H
H
NH2 CC NH2
methanamine
ethanamine
Draw:
111. Amides – contain the functional
group:
• IUPAC naming of amides:
-drop the final –e and add “amide”
NHC
O
Found at the end of a carbon chain
C
H
H
NH2C C
O
H
H
H
propanamide
113. Organic Reactions
• Substitution – replacement of one kind of atom or
group with another atom or group
• If this rxn occurs between an alkane and a
halogen, it is called halogenation.
*only happens with alkanes –
single bonds!!!!
114. Substitution
Butane bromine
+ Br2
+
Br + HBr
Bromobutane
Hydrogen
bromide
+
C4H10 + Br2 C4H9Br + HBr
The second Br can then substitute for another H.
For Ex: Find the products of
C3H8 + F2 C3H7F + HF
115. Addition –adding one or more groups at
a double or triple bond.
• Double bond is broken…becomes a single
bond.
*only happens with alkenes & alkynes
– double/triple bonds!!!!
116. Addition
• Alkene + Halogen Alkyl Halide
• The double bond is broken, and the halogen
adds at either side of where the double bond
was.
saturated
unsaturated
118. Esterification
• Organic Acid + Alcohol Ester + Water
-COOH -OH -COO -H2O
-These are slow reversible reactions
-similar to neutralization rxn in inorganic
Acid + base = salt + water
119. Saponification – is the hydrolysis of fats by
bases.
• The breaking of an ester to produce an organic
acid plus an alcohol.
Fat + water = organic acid + glycerol
(glycerol ester) (soap) (alcohol)
What is this the reverse process of?
Organic Acid + Alcohol Ester + Water
Esterification
120. Saponification - hydrolysis of an ester in
presence of a hot base (alkali)
Glycerol ester + 3 NaOH soap + glycerol
Fat base alcohol soap
121. Polymers- are composed of many repeating
units of monomers
• Natural polymers
-starch – long chains of sugars
-proteins – long chains of amino acids
-cellulose – made of repeating units of sugar
starch cellulose
123. Polymerization- formation of polymers
from monomers
• Formation of larger molecules from smaller ones.
2 Methods :
1. Condensation polymerization: bonding of
monomers by dehydration synthesis
Monomers have at least two functional groups
-OH on ends
125. Addition Polymerization -
C C C C C C+ +
monomer monomer
monomer
CC CC C C
polymer
ethylene
ethylene
ethylene
polyethylene
126. Finding missing reactants & products in
organic rxns
• In balanced rxns the number of atoms on the left must
equal the number of atoms on the right.
C2H6Ex.) Cl2 C2H5Cl+ +
Left side Right side missing
C = C = C =
H = H = H =
Cl = Cl = Cl =
Missing product must be HCl
This is a substitution rxn because hydrogen atom of
ethane is replaced by chlorine.
2
6
2
2
5
1
0
1
1
127. • Try this one: C2H4Ex.) C2H4 Br2+
What process makes…
fermentation
saponification
combustion
Condensation
polymerization
addition
polymerization
Br2
This is a addition rxn
128. Constitutional Isomers (Structural Isomers) are different compounds
of the same formula. The different structures from the previous slide for
the formula C4H10 is an example of Constitutional isomers.
Isomerism
129. Constitutional Isomers (Structural Isomers) are different compounds
of the same formula. The different structures from the previous slide for
the formula C4H10 is an example of Constitutional isomers.
How many isomers are there of an alkane containing five carbons
(C5H12)?
Isomerism
Isomer Strategy – Draw Lewis possible different length chains of
carbons atoms connected with a covalent bond.
130. Constitutional Isomers (Structural Isomers) are different compounds
of the same formula. The different structures from the previous slide for
the formula C4H10 is an example of Constitutional isomers.
How many isomers are there of an alkane containing five carbons
(C5H12)?
Isomerism
Isomer Strategy – Draw Lewis possible different length chains of
carbons atoms connected with a covalent bond.
C C C C C
Chains of 5 carbon atoms
H
H
HH
H HHH
HH
H H
131. What is an isomer?
• These compounds are
said to be isomers of one
another.
• Isomerism also occurs in
inorganic chemistry, but it
is less common.
132. If isomers have the same atoms in them, surely
they have the same properties, so what's the
point?
• In fact, these small changes in structure can have
significant effects on the properties of the substance!
• But, it is important to realize that this can have
significant effects in a living system.
• One optical isomer of glucose, for example, can be used
by a living cell, but the other isomer cannot.
• This is because the enzyme in the cell which recognizes
glucose is sensitive to only one form.
134. There are two types of isomerism common in
organic chemistry:
1. structural isomerism
• Which have the atoms of their molecules
linked in a different order.
• This can come about in one of three
ways:
135. Chain Isomerism
• Chain isomers of the same compound are very similar.
• There may be small difference in physical properties such
as melting or boiling point due to different strengths of
intermolecular bonding.
• Their chemistry is likely to be identical.
136. Positional Isomers
• Positional isomers are also usually similar.
• There are slight physical differences, but the chemical
properties are usually very similar.
• However, occasionally, positional isomers can have quite
different properties
137. Functional Group Isomers
• Functional group isomers are likely to be both
physically and chemically dissimilar.
138. NOMENCLATURE
1. Common system
a. Works best for low molecular weight hydrocarbons
b. Steps to give a hydrocarbon a common name:
1. Count the total number of carbon atoms in the molecule.
2. Use the Latin root from the following slide that corresponds to the
number of carbon atoms followed by the suffix “ane”.
3. Unbranced hydrocarbons use the prefix normal, or n-,
4. Branched hydrocarbons use specific prefixes, as shown on a
subsequent slide
139. NOMENCLATURE
Common system Examples
CH C
H
H
H
H
C
H
H
H
1. Give a name for the following compound
Step #1, count the number of carbons and write down the memorized Latin name
for that number (next slide)
Step #2, since this structure fits the alkane general formula, use the “ane” suffix
propane
Three carbon Latin root
Alkane suffix
140. Latin
Hydrocarbon
Roots
Number of
Carbons
Latin
Root
1 meth
2 eth
3 prop
4 but
5 pent
6 hex
7 hept
8 oct
9 non
10 dec
11 undec
Latin
Hydrocarbon
Roots
Number of
Carbons
Latin
Root
12 dodec
13 tridec
14 tetradec
15 pentadec
16 hexadec
17 heptadec
18 octadec
19 nonadec
20 eicos
21 unicos
22 doicos
C
H
H
H
C
H
C
H
HH
C
H
H
H
CH
H
H
C
C
H H
C
H
H
H H
H
n-butane
isobutane
H C C C H
H C H
H C H
H
H
H
H
H
H
Examples
neopentane