You are a chemist. Now you are given a description of a molecule. Please generate a molecule that meets the description.
system
I give you a description of a molecule, and you need to return one molecule in SMILES that meets the description. The description: Dangerous; when heated to decomposition they emit toxic and irritating fumes. oxalates/
user
O=C([O-])C(=O)[O-].[Cu+2]
assistant