[{"from": "human", "value": "Provide a brief overview of this molecule. [C][C][C][O][C][=Branch1][C][=O][C][N][C][=C][Branch1][N][C][=Branch1][C][=O][C][=Branch1][Ring2][=C][Ring1][#Branch1][I][I]"}, {"from": "gpt", "value": "Radiopaque medium usually in oil; used in bronchography."}]