Structure searching in CAS Online using STN Express:
An introductory workshop

Building structures

  1. Launch STN Express
  2. Choose Query from menu bar at top
    1. Choose Prepare Structure Query
    2. Choose New to create a new structure
    3. Choose Open to modify an existing structure
  3. The structure drawing part of STN Express will appear and consists of 4 main parts
    1. Blank screen
    2. Tool Palette
    3. Common Atoms and Bonds Palettes
    4. Pull-Down Menus
Tool palette
Tool Function
Pencil Draw atoms/bonds using current atom/bond
Rxn Enable reaction drawing tools
Ring Draw 3- to 15- member ring systems
Chain Draw 1- to 30- member chains
Eraser Delete objects
Rectangle Select (highlight) objects
Lasso Select (grab) objects
A Add text to screen (not searched)
? Help for this Palette

Common atoms and bonds palettes:

  • Click once for single use
  • Click twice in rapid succession for multiple use
  • Current atom or bond is shown in thick-line bordered boxes
  • Click box on far right to return to default values (carbon/single bond)