Solomons/SoloCh01
1.17 REPRESENTATION OF STRUCTURAL FORMULAS
HC
H
H
C
H
H
C
H
H
O H
Ball-and-stick model Dash formula
CH^3 CH^2 CH^2 OH OH
Condensed formula Bond-line formula
Figure 1.36 Structural formulas for propyl alcohol.
H COCH C
H
H
OC
H
H
H H CH 3 OCH 3
HH
HH
==
Dot structure Dash formula Condensed formula
1.17A Dash Structural Formulas
- Atoms joined by single bonds can rotate relatively freely with respect to one
another.
C
C
C
H H
H O
H
H HHH
C
C
C
H H
H O
H
H HH H
C C C
H H
H H
H HHO
H
or or
Equivalent dash formulas for propyl alcohol ⇒ same connectivity of the atoms
- Constitutional isomers have different connectivity and, therefore, must have
different structural formulas. - Isopropyl alcohol is a constitutional isomer of propyl alcohol.