
Organic chemistry is the study of
carbon-containing compounds
(especially compounds containing C-C
bonds)
 The
field of organic chemistry is very
important for a wide variety of reasons.
A huge number of carbon-containing
compounds are known.
 More than 16 million known compounds
 About 90% of new compounds made each
year contain carbon

Most of the advances in the
pharmaceutical industry are based on a
knowledge of organic chemistry.
 Many drugs are organic compounds

Life as we know it is based on organic
chemistry.
 Most biologically important compounds contain
carbon:
 DNA, RNA
 proteins
 carbohydrates
Organic compounds are
those compounds found in
any organism that is living or
was once living containing
carbon. Compounds lacking
carbon and not from living
organisms referred to as
“inorganic”.
Organic compounds are
those compounds found in
any organism that is living or
was once living containing
carbon.

Most organic compounds have a
“skeleton” that is composed of C-C
bonds.
 The C-C bonds may be single bonds, double
bonds, or triple bonds.

The “skeleton” of an organic compound
has H’s attached to it.
other “heteroatoms” like O, halogens or N
may be present as well
The number of bonds formed by C in an
organic compound is determined by the
electron configuration of C.
 Carbon has four valence electrons:
1s22s22p2

Carbon generally forms 4 equivalent
bonds.
 The formation of four equivalent bonds is
best explained using the concept of
hybrid orbitals.

Hybrid orbitals

When C forms four single bonds:
 sp3 hybrid orbitals are involved tetrahedral
geometry

When C forms a double bond:
 sp2 hybrid orbitals are used trigonal planar
geometry

When C forms a triple bond:
 sp hybrid orbitals are used linear geometry
Organic compounds contain not only
C-C bonds but also C-H bonds.


C-C and C-H bonds tend to be non-polar
because there is a small difference in
electronegativites

Most (but not all) organic compounds are
relatively non-polar
generally not very soluble in water

When we write a simple chemical formula,
such as CH4, we are actually writing what
we call a molecular formula

Molecular Formulas – show the atoms and
the number of atoms involved in a
molecule but nothing else

In organic chemistry, it is often more useful
to show structural formulas instead

Structural Formulas – show each type of
atom and how they are arranged in a
molecule
H
CH4
H - C - H
H
Molecular Formula
Structural Formula
3-D Structure
Structural formulas are important
in organic chemistry because of
isomers
Isomers are two compounds with
the SAME MOLECULAR formulas
but different structural formulas
-- they have different
chemical and physical properties
C3H8O

The simplest organic compounds are the
hydrocarbons:
organic compounds that contain only
carbon and hydrogen
four general types:
alkanes
alkenes
alkynes
aromatic hydrocarbons

Alkanes:
hydrocarbons that contain only single bonds

Examples:
Methane
Ethane

CH4
C2H6
Alkenes:
hydrocarbons that contain a C = C double
bond
H2C = CH2 (ethylene)

Alkynes:
hydrocarbons that contain a C
bond
H – C
C triple
C – H (acetylene)
There are others to follow but these are the
first three simplest organic molecules.
Organic compounds that are soluble in polar
solvents such as water generally have a polar
functional group present in the molecule.
An atom or group of atoms that influences
the way the molecule functions, reacts or
behaves.
An atom or group of atoms in a molecule that
undergoes predictable chemical reactions
The center of reactivity in an organic
molecule
Since functional groups are responsible for the many
of the chemical and physical properties of organic
compounds, we often classify and study organic
compounds by the type of functional group present.
Functional Type of
Group
Compound
C=C
alkene
C
alkyne
C
Example
H2C = CH2
HC
CH
C–O–H
alcohol
CH3OH
C–O–C
ether
CH3CH2OCH2CH3
C–N
amine
CH3NHCH3
Functional
Group
Type of
Compound
O
C–H
O
aldehyde
O
C–C–C
Example
CH3C – H
O
ketone
CH3 – C – CH3
Functional
Group
O
Type of
Compound
Carboxylic
C–O–H
acid
O
C–O–C
Example
O
CH3C – O – H
O
ester
CH3C – O – CH2CH3
Example: Name the
functional groups that are
present in the following
compounds:
O
CH3CH2OH
H2C = CHCOH
CH3CH2NCH3
CH3
1)Acyclic—contains no rings
in the structure
2)Carbocyclic—contains at
least one ring only made up
of carbon
3)Heterocyclic—contains at
least one ring that has an
element other than carbon in
it
acyclic
carbocyclic
heterocyclic