Download Introduction to Organic Chemistry (Carbon Chemistry)

Introduction to Organic Chemistry (Carbon Chemistry)!!
Carbon has the ability to form long chains of atoms held together by strong covalent bonds. Molecules with
over 700 carbon atoms bonded together are not uncommon! The carbon-carbon single bond is very strong and
very stable – it takes strong UV light or lots of heat to crack it.
The PROPERTIES OF ORGANIC COMPOUNDS are generally determined by three factors:
a) The carbon skeleton is a very stable, chemically unreactive structure.
b) The presence of double or triple bonds increases the reactivity of carbon skeletons.
c) “Functional groups" which are other atoms or groups of atoms attached to the carbon skeleton give
organic compounds their special chemical properties. For example alcohols derive their special properties
from the presence of the -OH group, carboxylic acids possess the -COOH group, etc.
Table 1: The Alkanes: compounds of only carbon and hydrogen with only single bonds
Molecular Formula
Structural Formula
Name
expanded
condensed
H
CH4
CH4
Methane
H C
Boiling Point C
-162
H
H
C2H6
H
H
H
C
C
H
H
CH3-CH3
ethane
CH3-CH2-CH3
Propane
H
Butane
Pentane
Hexane
Heptane
Octane
Nonane
Decane
“Monkeys Eat Purple Bananas” or whatever….
-89
ALKYL GROUPS
Carbon chains that ‘branch’ off a longer chain are named abit differently, they are called "alkyl" groups.
Complete the following chart.
Parent Alkane
Alkyl Group
Name
H
H
CH4 methane
-CH3
Methyl
H C
H
H
C2H6 ethane
H
H
H
C
C
H
H
C
H
H
H
H
H
C
C
H
H
-CH2CH3
Ethyl
H
C3H8 propane
STRUCTURAL ISOMERS - compounds that have the same molecular formulae but different structural formulae are
called structural isomers. One check on drawing isomers, is that they must have different names
Example 1: C4H10 has two (2) structural isomers:
1) butane as CH3-CH2-CH2-CH3 i.e.
H
OR
2) 2-methyl propane
H
H
H
C
C
C
C
H
H
H
H
H
or
CH3
CH3 CH
H
CH3
Types of drawings:
structural formula: shows all atoms and all bonds
condensed structural formula: shows all atoms and only the bonds that are important to help distinguish
compounds. CH2 =O.
simplified structural formulae: the atoms C and H are not written.
Naming Alkanes (hydrocarbons with only C-C single bonds):
1. Identify the longest chain – this is the base name.
2. Number the longest chain in a way to give any branches (alkyl groups) the lowest possible numbers.
3. Name the branches in alphabetical order, using a number to specifiy the position AND using prefixes (di,
tri…) if there are more than one of the same type. (e.g. 2,2-dimethylpentane)