[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule appears as a colorless oily liquid with a penetrating odor. Reacts with water and denser than water. Contact may irritate skin, eyes and mucous membranes. Toxic by ingestion and inhalation. Used to make pesticides."}, {"from": "gpt", "value": "[C][=Branch1][C][=O][C][Branch1][C][Cl][Branch1][C][Cl][Cl]"}]