[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule appears as a yellow-brown powder. Insoluble in water. Toxic by ingestion and inhalation and is a strong irritant. It is used in medicines."}, {"from": "gpt", "value": "[O].[O].[O].[O].[O].[O-2].[O][As][Branch1][C][O][O].[Fe+3]"}]