Specifying Variable Attachment Points

The Variable Attachment Point tool is used to specify multiple positions on a ring system where a substituent can attach.

 

 

  1. Click the Variable Attachment Point    icon.

  2. Click-and-drag your cursor from the substituent (unattached atom) to a position on the ring to create an attachment line.


  1. (Optional) You can click the Marquee    icon to move the variable point of attachment to a new location for easier viewing.

 

 

  Component

Characteristics
Substituent Atoms

Can be:

  • A single atom or an atom in a larger fragment.

  • Or contain an element, variable, shortcut, R-group with no additional attachments, or repeating group.

  • Locked to prevent additional substitution.

Cannot:

  • Have variable attachments to more than one ring system.

  • Be part of a repeating group.

  • Have the substituent for a variable point of attachment contain the ring attachment for a different variable point of attachment.

Variable Attachment Atoms

Can be:

  • A single atom or an atom in a larger fragment.

  • Or contain a non-metal element or the X, Q, or A variables.

  • Locked to prevent additional substitution.

Cannot:

  • Be a shortcut, a metal atom, or the M, Ak, Cb, Cy, or Hy variables.

  • Have an atom in a Repeating group selected as part of the variable point of attachment.

  • Have the substituent for a variable point of attachment contain the ring attachment for a different variable point of attachment.

Variable Attachment Bonds

  • Can be a single, double, triple, or unspecified bond.

  • Cannot be a stereo bond.

Core Structure

  • One or more substituents can be variably attached to the same atoms in the ring system.

  • No more than 20 total substituents can be variably attached to an individual ring system.

 

To Remove a Variable Attachment Point

  1. Click the Eraser    icon.

  2. To remove one of the ring attachments, click the individual dashed line.

  3. To remove the entire variable, click the substituent (attached atom). To remove the bond line, dashed line, or asterisk, click the individual components.

 

Learn More

Drawing and Editing Structures

Drawing Substructure Queries

Drawing Reaction Queries