By: Sarah Russell and Edward Moore
What are organic halides?
Organic halides are organic compounds
that contain one or more halogen atoms.
 In a hydrocarbon, one or more hydrogen
atoms are replaced by halide atoms
(fluorine, chlorine, bromine, iodine,
astatine)
 Also known as Halocarbons or Alkyl
Halides.

General formula: CnH2n+1X, where C
represents the carbon atoms, H
represents the hydrogen atoms, and X
represents the halide.
 Also represented as R-X, where R=alkyl
group, X=halogen substituent.

1,2-dichloroethane
http://en.wikipedia.org/wiki/1,2-Dichloroethane
Physical Properties
Bond strength decreases with an
increase in the size of the halogen
attached (the size of the p orbital
increases). This also causes the bond to
be longer.
 Boiling points are higher then alkanes.
Increase with increasing chain length
(containing the same halogen)
 Little solubility in water, but good
solubility in nonpolar solvents.

Naming
Same format as branched chain
hydrocarbons.
 1. Identify and name the parent chain
(longest) of Carbons.
 2. Identify and name the halogen
substituent(s) (remember to use lowest
possible numbers).
 3.List substituents in alphabetical order
with prefixes.

Note: the halogen branch is named by
shortening (fluoro, chloro, bromo, etc.)
 4. Write the IUPAC name of the
compound.

1.Parent chain: 4 (saturated) = BUTANE
2.Halogen substituent: 1-Bromine = 1-BROMO
3.1-bromo + butane
4.1-bromobutane (or just bromobutane)
http://science.pc.athabascau.ca/reagentstud.nsf/c982974ea911edc887257093006b238d/ee1bb4eb15b5e
248872570b2007751b0?OpenDocument
Condensed structural formula: CH3-CH2-CH2-CH2-Br
http://www.lookchem.com/cas-471/471-43-2.html
1.Parent chain: 2 (saturated): ETHANE
2.Halogen substituent: 1,1-Flourine=FLUORO, 2,2Chlorine=CHLORO
3.2,2-Dichloro-1,1-Difluoro + Ethane
4.2,2-dichloro-1,1-difluoroethane
Drawing structural formula
1. Draw the parent chain of Carbons
 2. Add the position and symbol for each
halogen atom
 3. Add the remaining Hydrogen atoms
(Carbon forms four covalent bonds
because it has 4 electrons)

1,3-dichloropropane
1. Parent chain of Carbon: “PROPANE” = 3 Carbon (saturated)
C–C–C
2. Position 1 and 3= DI (2), CHLORO = chlorine
C–C–C
|
|
Cl
Cl
3. Add Hydrogen (each Carbon need 4 bonds)
H
H H
|
|
|
H–C –C–C–H
|
| |
Cl H Cl
Reactions
2 main reactions that result in the
formation of organic halides:
Substitution and Addition.
 Difference between the 2 is the
hydrocarbons involved.

Addition reactions
Reaction in which substituents are
added to both carbons that share a
multiple bond.
 Similar to “Hydrogenation”, because
instead of Hydrogen, a halide is added
to an unsaturated hydrocarbon and
makes it saturated.
 Rapid rate of reaction because no
strong covalent bond is broken, no
separation of carbon atoms.

H H
| |
H-C=C-H
Ethene
+
+
Cl-Cl
Chlorine


H H
| |
H-C-C-H
| |
Cl-Cl
1,2-dichloroethane
As seen here, chlorine is being added to ethene, an unsaturated
hydrocarbon, which produces 1,2-dichloroethane, a saturated hydrocarbon.
Indicated by the arrows, Chlorine is being added to the new product, but for
this to happen the double bond in Ethene is broken up making it Ethane.
This process allows the electrons involved in the double bond to be freed so
that the chlorine atoms can attach.
H-C≡C-H
+
Br-Br
Ethyne
+
Bromine


Br Br
| |
H-C=C-H
1,2-dibromoethene
As seen here, bromine is being added to ethyne, an alkyne, which produces
1,2-dibromoethene, an alkene.
Indicated by the arrows, Bromine is being added to the new product, but for
this to happen the triple bond in Ethyne is broken up making it Ethene. This
process allows the electrons involved in the triple bond to be freed so that
the bromine atoms can attach.
Substitution reactions
Occurs when a hydrogen atom is
removed from a hydrocarbon and
replaced by a halide.
 The breaking of a carbon-hydrogen
bond in an alkane or aromatic ring
produces an organic halide and a
hydrogen halide.
 Slow reaction at room temp. (very few
molecules that collide are energetic
enough to break C-H bonds.

H
|
H-C-H
|
H
+
Br-Br

H-Br
+
H
|
H-C-Br
|
H
Methane + Bromine  Hydrogen Bromide + Bromomethane
In this reaction, Bromine is added to Methane to produce Hydrogen Bromide and
Bromomethane. As a substitution reaction, a hydrogen atom must be removed
from a hydrocarbon and replaced my a halide. One hydrogen on Methane is
replaced by a Bromine atom to produce Bromomethane. The left over product of
this reaction is a hydrogen atom and a bromine atom, which make Hydrogen
Bromide.
H HH
| | |
H-C-C-C-H
| | |
H HH
+
Cl-Cl

H-Cl
+
H HH
| | |
H-C-C-C-Cl
| | |
H H H
OR
H HH
Proane + Chlorine  Hydrogen Chloride + 1| | |
Chloroproane OR 2-Chloroprpane
H-C-C-C-H
| | |
In this reaction, Chlorine is added to Propane to produce Hydrogen H Cl H
Chloride and 1-Chloropropane OR 2-Chloropropane . As a substitution
reaction, a hydrogen atom must be removed from a hydrocarbon and
replaced my a halide. One hydrogen on Propane is replaced by a Chloride
atom to produce 1-Chloropropane OR 2-Chloropropane. The left over
product of this reaction is a hydrogen atom and a chlorine atom, which
make Hydrogen Chloride. This reaction does produce an isomer because
Propane can Chlorine can replace the hydrogen atoms in position 1 and 2.
Elimination Reactions
There is also a third type of reaction
involving organic halides, elimination
reactions.
 Elimination reactions are almost like the
opposite of addition reactions. Instead of
adding halogens to a hydrocarbon to
create an organic halide, halide atoms
can be removed from an organic halide
with a base to produce an unsaturated
hydrocarbon.

HH HH
| | | |
H-C-C-C-C-H
| | | |
H Cl H H
+
OH ̄

H HHH
| | | |
H-C=C-C-C-H
| |
HH
+
Cl ̄
+
H2O
OR
H H HH
| | | |
H-C-C=C-C-H
|
|
H
H
2-chlorobutane + hydroxide  1-butene + chlorine + water
2-butene
This is an example of an elimination reaction, where a base is added to an organic
halide to produce an unsaturated hydrocarbon and a halide. Here, the base which is
Hydroxide, breaks up the organic halide, 2-chlorobutane. This produces the
hydrocarbon of either 1-butene or 2-butene, because the halogen atom, chlorine,
has been removed which produces a chlorine ion also. Water is also produced
because 2 hydrogen atoms are sacrificed to make a double bond in the hydrocarbon
and the oxygen from hydroxide is left over.
Everyday use
Freons (chlorofluorocarbons) are used
in refrigerators and air conditioners
 Teflon (polytetraf) in cookware
 Many are toxic (carcinogenics)
 DDT (dichlorodiphenyltrichloroethane),
insecticide.
 PCB’s, (polychlorinated biphenyls) used
in electrical transformers

http://www.benbest.com/cryonics/s21cm99.html
http://www.jrank.org/health/pages/15856/dichlorodiphenyltrichloroethane-(DDT).html
http://www.lenntech.com/teflon.htm
http://www.axysanalytical.com/services/organochlorine_lega
cy_compounds/pcb_polychlorinated_biphenyls/
Fire retardation
 Anaesthesia
 Plastics manufacturing

http://www.diytrade.com/china/4/products/7291276/Alcopanel_FR__Aluminium_
Composite_Panel_Fire_Retardation_Grade.html
http://news.bbc.co.uk/2/hi/health/7468753.stm
http://inhabitat.com/scientists-develop-plastic-producing-bacteria/