[{"from": "human", "value": "Generate a molecule based on the given description. The molecule appears as a colorless liquid. Less dense than water. Vapors heavier than air. May be mildly toxic by ingestion, inhalation and skin absorption. Used to make plastics."}, {"from": "gpt", "value": "[C][C][C][=Branch1][C][=O][O][C][C][Branch1][C][C][C]"}]