1. SIDE-GROUP ISOMERS

2. SIDE-GROUP ISOMERS
Isomers
- Isomers are
chemicals which
have the same
chemical formula,
but different
arrangement of
atoms.
- Nomenclature
should help
differentiate one
isomer from
another.

3. SIDE-GROUP ISOMERS
Propyl isomers:
n-propyl group CH3
l
CH2
l
CH2
CH3-CH2-CH2-CH2-CH-CH2-CH2-CH2-CH2-CH3
l
isopropyl group
CH3-CH-CH3
l
CH3-CH2-CH2-CH2-CH-CH2-CH2-CH2-CH2-CH3

4. SIDE-GROUP ISOMERS
Propyl isomers:
n-propyl group
isopropyl group

5. SIDE-GROUP ISOMERS
Butyl isomers:
n-butyl group sec-butyl group
(s-butyl)
CH3
l
CH2
l
CH2
l
CH3-CH-CH2-CH3
CH3-CH2-CH2-CH2-CH-CH2-CH2-CH2-CH3
CH2 CH3-CH2-CH2-CH2-CH-CH2-CH2-CH2-CH3
l
isobutyl group
l
tert-butyl group
(t-butyl)
CH3-CH-CH3 CH3
l l
CH2 CH3-C-CH3
CH3-CH2-CH2-CH2-CH-CH2-CH2-CH2-CH3
l
CH3-CH2-CH2-CH2-CH-CH2-CH2-CH2-CH3
l

6. SIDE-GROUP ISOMERS
Butyl isomers:
n-butyl group sec-butyl group
(s-butyl)
isobutyl group tert-butyl group
(t-butyl)

7. SIDE-GROUP ISOMERS
Terms:
Iso – “equal”/”middle”
CH3-CH-CH3
(unlike prefixes like “di” l
and “tri”, the “i” in iso CH2
affects the alphabetical CH3-CH2-CH2-CH2-CH-CH2-CH2-CH2-CH3
l
order)
Sec – “secondary”
2 carbons adjacent to the CH3-CH-CH2-CH3
carbon that is attached to CH3-CH2-CH2-CH2-CH-CH2-CH2-CH2-CH3
l
the main chain
Tert – “tertiary” CH3
l
3 carbons adjacent to the CH3-C-CH3
carbon that is attached to CH3-CH2-CH2-CH2-CH-CH2-CH2-CH2-CH3
l
the main chain

8. SIDE-GROUP ISOMERS
IUPAC naming system:
Name the following molecules
H3C CH3
H3C CH3
H3C CH3
H3C CH2
CH3
5-tert-butylnonane 4-isopropylhept-1-ene

9. AROMATIC HYDROCARBONS

10. AROMATIC HYDROCARBONS
Aromatic hydrocarbons contain a benzene
ring, C6H6, as a base
Most of these compounds are volatile (easily
vaporized) and are associated with a distinct
aroma (good or bad)

11. AROMATIC HYDROCARBONS
IUPAC naming system:
With side-chains, aromatic naming follows similar
rules as for C-chains.
methylbenzene chlorobenzene ethylbenzene

12. AROMATIC HYDROCARBONS
IUPAC naming system:
When benzene is considered to be a side group,
it is called a phenyl group
3-phenylheptane

13. AROMATIC HYDROCARBONS
IUPAC naming system:
When only two groups are present on benzene,
the following prefixes are used:
ortho meta para
o-dimethylbenzene m-dimethylbenzene p-dimethylbenzene
1,2-dimethylbenzene 1,3-dimethylbenzene 1,4-dimethylbenzene

14. AROMATIC HYDROCARBONS
Solve these Rebus puzzles: