ChemSketch: Drawing polymers with repeating units

Description
ChemSketch supports drawing polymers using repeating unit notation, which is useful for documenting structures of macromolecules and for communication in reports.

Solution

1. Open ChemSketch and switch to the Structure mode.
2. Draw the repeating unit monomer:

Include open valences or appropriate end groups where polymerization occurs.
Note: The draw chains () tool may be useful. Click, drag and release to draw a chain (length is defined by the cursor ); holding “Ctrl” while using this tool will produce a linear chain.

It is sometimes desirable to leave undefined end groups. To adjust the display settings for terminal carbons, select the structure using the Select button () then right-click and select Structure Properties from the context menu. Turn off Terminal Carbons in the Common tab and click Apply.

3.  Use polymer tools:

Mark the repeating unit and specify repeat brackets.
The Brackets Tool in the top toolbar ( ) allows you to draw brackets of a selected style and type around an existing structure. There are a number of possible combinations of styles and types; explore the drop-down menus for each option to find the combination that suits your needs. You can also define mole/mass fraction and number-average MM. Note: The Brackets Tool can be used to modify existing brackets. Open the tool and select the brackets you would like to modify, make changes, and then click Apply.

If the repeat unit of your polymer has been defined with a number, as shown above, the status bar at the bottom of the window will show the full molecular formula, FW, and M_mi.

4.  You can also use Template Window

Access the polymer templates by clicking ( ) to open the Template Window or from the menu Templates > Template Window:

Go to Organizer and place a check mark next to Polymer Templates. It will appear in the Template Window list.