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

Types of structure searches: Family search

  • Family search retrieves substances which match the query exactly and any multi-component substances that contain the exact query as one of the components
    • All positions in query are blocked for further substitution
    • All query rings are isolated
    • No variable nodes are allowed in the query
    • Variable bond values are allowed in the query
    • Retrieves all substances having the same connection table
      • Unsubstituted substance
      • Stereoisomers
      • Isotopically labelled substances
      • Radicals
      • Ions
      • Homopolymers
    • Retrieves multi-component substances that have the query as one of the components
  • Family search may be used to find polymers of a specific monomer
  • Family search will add hydrogens to all vacant atoms on the substructure drawn
  • Family search will not permit any other non-hydrogen atoms to be present in the component corresponding to the substructure drawn. Any atoms may be present in other component(s).