Structure searching in CAS Online using STN Express:
An introductory workshop
Types of structure searches
| Type of Substance Retrieved | Exact | Family | Sub-structure (SSS) |
|---|---|---|---|
| Structure with no additional substitution | X | X | X |
| Radiolabeled forms of the substance | X | X | X |
| Steroisomers | X | X | X |
| Homopolymers | X | X | X |
| Free radicals | X | X | X |
| Charged compounds | X | X | X |
| Salts and mixtures | X | X | |
| Addition compounds | X | X | |
| Copolymers | X | X | |
| Structures with additional substitution | X |
A fourth type of structure search is also available.
Closed substructure searches (CSS)
- Substance search which matches exactly a query and which contains system-defined variables.
- No further substitution is allowed except where specified.