Drawing Structural Formulas Using ChemDraw
In this PC Lab exercise in the ChemTech PC Lab (Foster Hall
326), you will be using the software ChemDraw, purchased from Cambridge
Software by a National Science Foundation grant to the Chem Dept. This software
allows one to easily generate structural formulas of complicated organic
molecules for printout or inclusion in other documents. Today we will use this
program to draw the structural formula of aspirin.
- Launch ChemDraw by clicking on
START/Programs/Chemistry/Cambridge Software/ChemDraw Pro.
- Familiarize yourself with the graphical user interface of
the program. First use the expand button in the upper right hand corner
of a window to make use of the entire screen.
- Note the Tool bar that appears on the right side
of the screen. By positioning the cursor over any one of these buttons the
program tells you the function of that tool button.
- Select the benzene ring tool button (appears at
the bottom of the tool bar).
- Click somewhere near the center of the white drawing
space and a benzene ring will appear on the screen. This is the basic
structural element of the compound.
- At any time, a command may be "undone" by
choosing Undo in the Edit menu.
- Additional groups may be added to the benzene ring by
selecting the Bond tool near the top of the tool bar. With this
selected, drag from one of the carbon atoms on the ring to a point outside the
ring to append a carbon atom to the ring. Continue doing this until you have
the basic skeleton of the molecule of interest, not worrying yet that some of
these new atoms should not be carbons but should be Oxygens. That will be fixed
- To make a double bond use the Bond tool and drag over the
top of an existing single bond to make it into a double bond. This will be
needed to create C=O bonds.
- Now you are ready to convert some of these atoms from
carbon (the default) to oxygen. To do this, simply position the cursor over the
top of the desired atom until the black square box appears, but DO NOT click the
atom. Simply type an "O" to change the selected atom to an Oxygen.
- After you have finished getting the structure you want,
use the Text tool to annotate the drawing by putting the name of the compound
above it, and putting your name in the upper right hand corner.
- Save the structure on your U: drive and generate a
printout of the structure to hand in.
OPTIONAL: Convert this 2-D structural formula to 3-D by
copying it and pasting it into the program CHEM3D. After the paste you need to
select MM/Minimize Structure to refine the structures geometry into
something energetically plausible.