[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule appears as a colorless, fuming liquid with a pungent odor. Density 9.2 lb / gal. Flash point 40 \u00b0F. Vapor, which is heavier than air, irritates the eyes and mucous membranes. Corrosive to metals and tissue."}, {"from": "gpt", "value": "[C][C][=Branch1][C][=O][Cl]"}]