[{"from": "human", "value": "Synthesize a molecule that matches the given characteristics. The molecule is the monohydrate of calcium acetate. It has a role as a chelator. It contains a calcium acetate."}, {"from": "gpt", "value": "[C][C][=Branch1][C][=O][O-1].[C][C][=Branch1][C][=O][O-1].[O].[Ca+2]"}]