Atom Maps:

• Atom map is part of Isomeric SMILES. Recent change.

• General Syntax:

The map is always the last part of the atom expression, delimited by the colon character.

[13C@H1+:34]

Why the change?

+ Convenient. A single string defines all relevant connectivity data.

+ Processing maps is automatic.

+ Hydrogens mapped easily / correctly.

- Harder to read reaction SMILES with maps.

- Isomeric SMILES are larger.